Title of Invention	A TUNABLE DISTRIBUTED VOLTAGE CONTROLLED OSCILLATOR FOR GENERATING HIGH FREQUENCY MICROWAVE SIGNALS
Abstract	This invention relates to a tunable distributed voltage controlled oscillator for generating high frequency microwave signals.According to the invention there is provided a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, the oscillator comprising a plurality of stages of complimentary metal oxide semiconductor (CMOS) inverters in parallel configuration, each of the inverters comprising a p-metal oxide semiconductor field effect transistor (MOSFET) at the top and a n-metal oxide semiconductor field effect transistor (MOSFET) at the bottom with their gates connected to a supply voltage and to a gate transmission line and their drains connected to the supply voltage and to a drain transmission line, the drain transmission line and the gate transmission line being connected to each other through a feed back path, the drain transmission line and the gate transmission line each comprising a plurality of coplanar wave guides in series, the number of coplanar wave guide in each of the gate and drain transmission lines being greater than the number of stages of CMOS inverters by a factor of 1, the body of the p-MOSFET being inwardly directed and connected to a forward body bias voltage and the source of the p-MOSFET being connected to the supply voltage and the body of the n-MOSFET being outwardly directed and the body and source of the n-MOSFET being earthed, the gate transmission line further comprising a frequency collector.

Title of Invention

A TUNABLE DISTRIBUTED VOLTAGE CONTROLLED OSCILLATOR FOR GENERATING HIGH FREQUENCY MICROWAVE SIGNALS

Abstract

This invention relates to a tunable distributed voltage controlled oscillator for generating high frequency microwave signals.According to the invention there is provided a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, the oscillator comprising a plurality of stages of complimentary metal oxide semiconductor (CMOS) inverters in parallel configuration, each of the inverters comprising a p-metal oxide semiconductor field effect transistor (MOSFET) at the top and a n-metal oxide semiconductor field effect transistor (MOSFET) at the bottom with their gates connected to a supply voltage and to a gate transmission line and their drains connected to the supply voltage and to a drain transmission line, the drain transmission line and the gate transmission line being connected to each other through a feed back path, the drain transmission line and the gate transmission line each comprising a plurality of coplanar wave guides in series, the number of coplanar wave guide in each of the gate and drain transmission lines being greater than the number of stages of CMOS inverters by a factor of 1, the body of the p-MOSFET being inwardly directed and connected to a forward body bias voltage and the source of the p-MOSFET being connected to the supply voltage and the body of the n-MOSFET being outwardly directed and the body and source of the n-MOSFET being earthed, the gate transmission line further comprising a frequency collector.

Full Text	FORM 2 THE PATENTS ACT, 1970 (39 of 1970) As amended by the Patents (Amendment) Act, 2005 & The Patents Rules, 2003 As amended by the Patents (Amendment) Rules, 2006 COMPLETE SPECIFICATION (See section 10 and rule 13) TITLE OF THE INVENTION A tunable distributed voltage controlled oscillator for generating high frequency microwave signals APPLICANTS Indian Institute of Technology, Bombay, an autonomous research and educational institution established in India by a special Act of the Parliament of the Republic of India under the Institutes of Technology Act 1961, Powai, Mumbai 400076, Maharashtra, India INVENTOR Bhattacharyya Kalyan, Electrical Engineering Department, Indian Institute of Technology, Bombay, Powai, Mumbai 400076, Maharashtra, India, an Indian national PREAMBLE TO THE DESCRIPTION The following specification particularly describes the nature of this invention and the manner in which it is to be performed : FIELD OF THE INVENTION This invention relates to a tunable distributed voltage controlled oscillator for generating high frequency microwave signals. BACKGROUND OF THE INVENTION Electrical or electronic communication networks like telecommunication, satellite communication, terrestrial communication, microwave communication or radar communication networks operate on different frequency signals. Microwave radiations have a wide range of frequencies and their application areas differ depending upon their frequencies. For instance, microwave frequency signals of 1 - 2 GHz find application in mobiles. Microwave frequency signals of 2 - 4 GHz are used in heating / cooking applications. High frequency electrical or electronic communication networks like radar or satellite networks or mobile telecommunication backbone networks operate on k band (frequencies of 18 to 27 GHz) and ku band (frequencies of 12 to 18 GHz). Microwave tubes are generally used for generating high frequency microwave signals. Microwave tubes are heavy and bulky and occupy large area and are unwieldy to handle. Besides, they are very expensive and their power consumption is very high. Distributed voltage oscillators for generating frequency signals are reported. A distributed voltage oscillator comprises n-MOSFETs (metal oxide semiconductor field effect transistors). (Exploiting CMOS Reverse Interconnect Scaling in Multigigahertz Amplifier and Oscillator Design by Bendik Kleveland et ai, IEE Journal of Solid State Circuits, Vol 36 No 10 October 2001). Its power consumption and fabrication cost are high and power output (output signal strength) is low. It generates a fixed frequency and hence a fixed frequency signal. In order to generate a range of frequency signals corresponding number of oscillators will be required. Cost, power consumption and size and space for occupation of the oscillator are increased because of this also. Distributed voltage controlled oscillators for generating frequencies are also reported. A distributed voltage controlled oscillator also comprises (n-MOSFETs (metal oxide semiconductor field effect transistors). (Silicon Based Distributed Voltage-Controlled Oscillators by Hui Wu et al, IEE Journal of Solid State Circuits, Vol 36 No 3 March 2001). It generates a range of low frequency signals and its power consumption is high and power output is low. OBJECTS OF THE IVENTION An object of the invention is to provide a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, which oscillator is economical, compact, light weight, occupies reduced surface area and is easy to handle. Another object of the invention is to provide a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, which oscillator consumes very low power and gives high power output (output signal strength). Another object of the invention is to provide a high frequency electrical or electronic communication network comprising a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, which oscillator is economical, compact, light weight, occupies reduced surface area and is easy to handle. Another object of the invention is to provide a high frequency electrical or electronic communication network comprising a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, which oscillator consumes very low power and gives high power output (output signal strength). DETAILED DESCRIPTION OF THE INVENTION According to the invention there is provided a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, the oscillator comprising a plurality of stages of complimentary metal oxide semiconductor (CMOS) inverters in parallel configuration, each of the inverters comprising a p-metal oxide semiconductor field effect transistor (MOSFET) at the top and a n-metal oxide semiconductor field effect transistor (MOSFET) at the bottom with their gates connected to a supply voltage and to a gate transmission line and their drains connected to the supply voltage and to a drain transmission line, the drain transmission line and the gate transmission line being connected to each other through a feed back path, the drain transmission line and the gate transmission line each comprising a plurality of coplanar wave guides in series, the number of coplanar wave guide in each of the gate and drain transmission lines being greater than the number of stages of CMOS inverters by a factor of 1, the body of the p-MOSFET being inwardly directed and connected to a forward body bias voltage and the source of the p-MOSFET being connected to the supply voltage and the body of the n-MOSFET being outwardly directed and the body and source of the n-MOSFET being earthed, the gate transmission line further comprising a frequency collector. According to the invention there is also provided a high frequency electrical or electronic communication network comprising a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, the oscillator comprising a plurality of stages of complimentary metal oxide semiconductor (CMOS) inverters in parallel configuration, each of the inverters comprising a p-metal oxide semiconductor field effect transistor (MOSFET) at the top and a n- metal oxide semiconductor field effect transistor (MOSFET) at the bottom with their gates connected to a supply voltage and to a gate transmission line and their drains connected to the supply voltage and to a drain transmission fine, the drain transmission line and the gate transmission line being connected to each other through a feed back path, the drain transmission line and the gate transmission line each comprising a plurality of coplanar wave guides in series, the number of coplanar wave guide in each of the gate and drain transmission lines being greater than the number of stages of CMOS inverters by a factor of I, the body of the p-MOSFET being inwardly directed and connected to a forward body bias voltage and the source of the p-MOSFET being connected to the supply voltage and the body of the n-MOSFET being outwardly directed and the body and source of the n-MOSFET being earthed, the gate transmission line further comprising a frequency collector. The following is a detailed description of the invention with reference to the accompanying drawings, in which: The tunable distributed voltage controlled oscillator 1A as illustrated in Figs 1 and 2 of the accompanying drawings comprises 3 stages of complementary metal oxide semiconductor (CMOS) inverters 2, 3 and 4 in parallel configuration. Each of the inverters comprises a p-metal oxide semiconductor field effect transistor (MOSFET) 5 at the top and a n-metal oxide semiconductor field effect transistor (MOSFET) 6 at the bottom.. The gates 7 and 8 of the transistors are connected to a supply voltage 9 and to a gate transmission line 10, respectively. The drains 11 and 12 of the transistors are connected to the supply voltage 9 and to a drain transmission line 13, respectively. The gate transmission line and drain transmission line are connected to each other through a feed back path 14. The gate transmission line and drain transmission line each comprises four coplanar wave guides (CPW) 15 and 16 in series, respectively. The body 17 of transistor 5 is inwardly directed and connected to a forward body bias (FBB) voltage 18 and the source 19 of transistor 5 is connected to the supply voltage 9. The body 20 of transistor 6 is outwardly directed and the body 20 and source 21 of transistor 6 are earthed. 22 is a frequency collector connected to the gate transmission line. Preferably each of the transistors is 0.18 Mm size. A supply voltage is given to the transistors to keep them in the operative mode. On applying varying FBB voltages to the body nodes of the transistors, correspondingly varying frequency signals are generated in the drains. Varying frequency signals also can be generated by varying the supply voltage. The frequency signals add up in the drain transmission Vine in the forward propagating direction. The frequency signals travel down the gate transmission line through the feed back path and are collected at frequency collector Fig 1 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to an embodiment of the invention; Fig 2 is an enlarged view of the portion marked X in Fig 1; Fig 3 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to another embodiment of the invention; Fig 4 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to another embodiment of the invention; Fig 5 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to another embodiment of the invention; Fig 6 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to another embodiment of the invention; and Fig 7 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to another embodiment of the invention. The tunable distributed voltage controlled oscillator 1A as illustrated in Figs 1 and 2 of the accompanying drawings comprises 3 stages of complementary metal oxide semiconductor (CMOS) inverters 2, 3 and 4 in parallel configuration. Each of the inverters comprises a p-metal oxide semiconductor field effect transistor (MOSFET) 5 at the top and a n-metal oxide semiconductor field effect transistor (MOSFET) 6 at the bottom. The gates 7 and 8 of the transistors are connected to a supply voltage 9 and to a gate transmission line 10, respectively. The drains 11 and 12 of the transistors are connected to the supply voltage 9 and to a drain transmission line 13, respectively. The gate transmission line and drain transmission line are connected to each other through a feed back path 14. The gate transmission line and drain transmission line each comprises four coplanar wave guides (CPW) IS arvd 16 in series, respectively. The body 17 of transistor 5 is inwardly directed and connected to a forward body bias (FBB) voltage 18 and the source 19 of transistor 5 is connected to the supply voltage 9. The body 20 of transistor 6 is outwardly directed and the body 20 and source 21 of transistor 6 are earthed. 22 is a frequency collector connected to the gate transmission line. Preferably each of the transistors is 0.18 (pm size. A supply voltage is given to the transistors to keep them in the operative mode. On applying varying FBB voltages to the body nodes of the transistors, correspondingly varying frequency signals are generated in the drains. Varying frequency signals also can be generated by varying the supply voltage. The frequency signals add up in the drain transmission line in the forward propagating direction. The frequency signals travel down the gate transmission line through the feed back path and are collected at frequency collector In the case of the tunable distributed voltage controlled oscillators IB and 1C of Figs 3 and 4 of the accompanying drawings respectively the oscillators comprise a variable capacitance device 23 in series with the gate transmission line and parallel to the drain transmission line, respectively. The varactors are connected to the supply voltage 9. Preferably, the variable capacitance device comprises a pair of metal oxide semiconductors (MOS) varactors. By changing the voltage to the varactors the capacitance of the varactors and hence the capacitance of the oscillators can be varied. Thus by changing both the FBB voltages and the supply voltage to the varactors additional high frequency microwave signals can be generated by the oscillator of Figs 3 and 4. The tunable distributed voltage controlled oscillators of Figs ID, IE and IF, of Figs 5, 6 and 7 of the accompanying drawings include an additional stage of CMOS inverter 24. The oscillators of Figs 5 to 7 are otherwise similar to and function in the same manner as the oscillators of Figs 1 and 2, 3 and 4 respectively. It is understood that the number of stages of CMOS inverters can vary and can be more than 3 or 4 and that the number of (CPWs) in each of the gate and gain transmission lines should be greater than the number of CMOS inverters by a factor 1. Oscillators comprising such configurations of CMOS invertors and (CPWs) are obvious to a person skilled in the art and are to be construed and understood to be within the scope of the invention. The tunable distributed voltage controlled oscillator of the invention generates high frequency microwave signals in the range of 17.33 to 24.09 GHz. Power consumption by the oscillator is very low as it operates at low voltages in the range of 0.9 to 1.8 volts. The power output (output signal strength) of the oscillator is high in the range of 4.9 to 4.8 dBm (3.1 to 3.05 milliwatts). The oscillator is very compact as the CMOS inverters used in the invention are miniature in size being of the order of 0.18 urn. Therefore, the oscillator is light weight and occupies reduced surface area and is easy to handle. It is also economical in terms of initial cost and operating cost. The oscillator can be advantageously used in high frequency electrical or electronic communication networks like radar or satellite communication networks or mobile telecommunication backbone networks. The following examples are illustrative of the invention but not limitative of the scope thereof: Example 1 Simulation tests were carried out with a typical oscillator of Fig 1. The supply voltage was maintained at 1 .IV and the FBB voltages were varied and the results were as shown in the following Table 1 below: Table 1 FBB voltage Oscillator Frequency (GHz) Power Output (dBm) Phase Noise dBc/Hz (1 MHz offset) 1.8 V 23.97 0.301 -97.696 1.35 V 23.59 0.827 -99.26 Simulation tests were also carried out with the typical oscillator of Fig 1, where the FBB voltage was maintained at 1.8V and the supply vol results were as shown in the following Table 2: Table 2 Supply Voltage Oscillator Frequency (GHz) Power Output (dBm) Phase Noise dBc/Hz at 1 MHz offset 0.9 V 23.84 -0.8 -96.155 1.0V 23.88 0.2 -96.593 1.1 V 23.97 0.301 -97.696 1.2 V 24.09 -1.0 -95.6 It is seen from the data in Table 1 that with small change of FBB voltage by 0.45V (1.8V to 1.35V), it is possible to achieve a frequency of 380 MHz (23.97 to 23.59 GHz) at low noise level of operation. It is seen from the data in Table 2 that by varying the supply voltage from 0.9V to 1.2 V, it is possible to achieve frequency tuning from 23.84GHz to 24.09GHz. In other words, tuning of frequency of (24.09 -23.84 GHz) = 250MHz is achieved by change of supply voltage by 0.3V (1.2V -0.9V) keeping the body bias voltage constant. It shows that the centre frequency of the oscillator is tunable by 250MHz by changing the supply voltage from 0.9V to 1.2V, In real-life the voltage can be increased up to 1.8V and hence the projected tuning range of centre frequency over the supply voltage is at least 500MHz. The noise level of operation is also very low. Example 2 Simulation tests were carried out with a typical oscillator of Fig 3 by varying both the FBB voltage and the varac voltage and the results were as shown in Table 3 below: Table 3 FBB Voltage Varac Voltage Oscillator Frequency (GHz) Power output (dBm) Phase noise dBc/Hz (1MHz offset) 1.8 V I.8V 23.53 -6.862 -92.26 1.35 V 1.8V 23.14 -6.757 -93.286 1.35 V 1.0 V 23.10 -7.996 -93.2 It is seen from the data in Table 3 that a frequency tuning of 390MHz (23.53-23.14 GHz) is achieved by varying FBB voltage by 0.45V (1.8V to 1.35V). It is also possible to carry out frequency tuning of 40MHz (23.14-23.10 GHz) concurrently by changing varactor bias voltage by 0.8V (1.8V to 1.0V). Total tuning by FBB voltage and series varactors is 430MHz (23.53 to 23.10 GHz). The noise level of operation is also very low. Example 3 Simulation tests were carried out with a typical oscillator of Fig 4 by varying both the FBB voltage and the varac voltage and the results were as shown in Table 4 below: Table 4 FBB Voltage Varac Voltage Oscillator frequency (GHz) Power output (dBm) Phase Noise dBc/Hz (1MHz offset) 1.8 V 0.9 V 22.79 0.622 -99,06 1.35 V 0.9 V 22.45 1.095 -99.968 1.35 V 1.8 V 22.11 0.56 -98.959 It is seen from the data in Table 4 that a frequency tuning of 340MHz (22,79 - 22. 45 GHz) is achieved by varying FBB of voltage by 0.45V (1.8V to 1.35V). It is also possible to carry out frequency tuning of 340MHz (22.45-22.11 GHz) concurrently by changing varactor bias voltage by 0.9V (0.9V to 1.8V). Total tuning by FBB voltage and parallel varactors is 680MHz (22.79 to 22.11 GHz). The noise level of operation is also very low. Example 4 Simulation tests were carried out with a typical oscillator of Fig 5 by keeping the supply voltage at I.IV and varying the FBB voltage and the results were as shown in Table 5 below: Table 5 FBB Voltage Oscillator frequency (GHz) Power (dBm) Phase Noise dBc/Hz at 1 MHz offset 1.8 V 18.64 4.918 -102.407 1.35 V 18.37 4.842 -103.46 Simulation tests were also carried out with a typical oscillator of Fig 5 by keeping the FBB voltage at 1.8V and varying the supply voltage and the results were shown in Table 6 below: Table 6 Supply Voltage Oscillator Frequency (GHz) Power (dBm) Phase Noise dBc/Hz (1 MHz offset) 0.9 V 18.44 3.822 -98.622 1.0V 18.54 4.362 -101.2 1.1 V 18.64 4.918 -102.407 1.2 V 18.73 4.836 -100.14 1.3 V 18.83 4.887 -94.872 1.4 V 18.93 4.841 -89.362 1.5 V 19.02 4.708 -87.307 1.6 V 19.08 4.524 -92.307 1.7 V 19.11 4.302 -92.157 It is seen from the data in Table 5 that with small change of FBB voltage by 0.45V (1.8V to 1.35V), it is possible to achieve a frequency change of 270 MHz (18.64 to 18.37 GHz) at low noise level of operation. It is seen from the data in Table 6 that it is possible to achieve frequency tuning of 18.44 GHz to 19.11 -GHz by varying supply voltage from 0.9 to 1.7V ie a tuning of frequency (19.11 - 18.44 GHz = 670 MHz by change of supply voltage by 0.8V (1.7V - 0.9V). Example 5 Simulation tests were carried out with a typical oscillator of Fig 6 by changing both the FBB voltage and varac voltage and the results were as shown in Table 7 below: Table 7 Body Bias Varac Bias Oscillator Frequency (GHz) Power output (dBm) Phase Noise dBc/Hz (1MHz offset) 1.8V 1.8V 18.09 -4.404 -100.4 1.35 V 1.8 V 17.82 -4.621 -101.49 1.35 V 1.0V 17.79 -5.817 -100.90 It is seen from the data in Table 7 that frequency tuning of 270MHz (18.09 to 17.82 GHz) is achieved by varying FBB voltage by0.45V (1.8V to 1.35V). Frequency tuning of 30 MHz (17.82 - 17.79 GHz) is concurrently achieved by series varactors by changing the varactor bias by 0.8V (1.8V to 1.0V). Total tuning by FBB and series varactors is 300 MHz (18.09 to 17.79 GHz). The oscillator thus performs in both K and Ku bands. The noise level of operation is also very low. Example 6 Simulation tests were carried out with a typical oscillator of Fig 7 by changing both the FBB voltage and varac voltage and the results were as shown in Table 8 below: Table 8 FBB voltage Varac voltage Oscillator Frequency GHz Power (dBm) Phase Noise dBc/Hz at 1MHz offset 1.8 0.9 17.77 4.845 -101.491 1.35 0.9 17.53 4.821 -102.037 1.35 1.8 17.33 4.681 -103.067 It is seen from the data in Table 8 that a frequency tuning of 240MHz (17.77 -17.53GHz) is achieved by varying FBB voltage by 0.45V (1.8V to 1.35V). It is also possible to achieve frequency tuning of 200MHz (17.53-17.33GHz) concurrently by changing varactor bias by 0.9V (1.8V to 0.9V). Total tuning by FBB and parallel varactor is 440MHz (17.77 to 17.33 GHz). The noise level of operation is also very low. Example 7 The oscillators of the invention were also found to emit very low power in 2nd and 3rd harmonics frequencies as can be seen from the typical examples in Tables 9 and 10 below. Table 9 gives harmonics of the typical oscillator of Fig 4 and Table 10 gives harmonics of the typical oscillator of Fig 7. Table 9 FBB Voltage Varac Voltage Harmonics Oscillator Frequency (GHz) Power emitted (dBm) 1.8 0.9 1 22.79 0.622 2 45.57 -23.387 3 68.36 -46.094 1.35 0.9 1 22.45 1.095 2 44.90 -24.539 3 67.35 -45.075 1.35 1.8 1 22.11 0.56 2 44.22 -26.565 3 66.33 -47.013 Table 10 FBB Voltage Varac Voltage Harmonics Oscillator Frequency (GHz) Power emitted (dBm) 1.8 1.8 1 18.09 -4.404 2 36.18 -21.714 3 54.27 -27.447 1,35 1.8 1 17.82 -4.621 2 35.63 -23.437 3 53.45 -29.247 1.35 1.2 1 17.79 -5.817 2 35.58 -23.037 3 53.37 -38.437 We Claim : 1. A tunable distributed voltage controlled oscillator for generating high frequency microwave signals, the oscillator comprising a plurality of stages of complimentary metal oxide semiconductor (CMOS) inverters in parallel configuration, each of the inverters comprising a p-metal oxide semiconductor field effect transistor (MOSFET) at the top and a n-metal oxide semiconductor field effect transistor (MOSFET) at the bottom with their gates connected to a supply voltage and to a gate transmission line and their drains connected to the supply voltage and to a drain transmission line, the drain transmission line and the gate transmission line being connected to each other through a feed back path, the drain transmission line and the gate transmission line each comprising a plurality of coplanar wave guides in series, the number of coplanar wave guide in each of the gate and drain transmission lines being greater than the number of stages of CMOS inverters by a factor of 1, the body of the p-MOSFET being inwardly directed and connected to a forward body bias voltage and the source of the p-MOSFET being connected to the supply voltage and the body of the n-MOSFET being outwardly directed and the body and source of the n-MOSFET being earthed, the gate transmission line further comprising a frequency collector. 2. The tunable oscillator as claimed in claim 1, which comprises a variable capacitance device connected parallel to the drain transmission line or in series with the gate transmission line. 3. The tunable oscillator as claimed in claim 2, wherein the variable capacitance device comprises a pair of metal oxide semiconductor (MOS) varactors. 4. The tunable oscillator as claimed in anyone of claims 1 to 3, wherein each of the p-MOSFETS and n-MOSFETS is 0.18 pm size. 5. The tunable oscillator as claimed in anyone of claims 1 to 4, which comprises three stages of CMOS inverters in parallel configuration. 6. The tunable oscillator as claimed in any one of claims 1 to 4, which comprises four stages of CMOS inverters in parallel configuration. 7. A high frequency electrical or electronic communication network comprising a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, the oscillator comprising a plurality of stages of complimentary metal oxide semiconductor (CMOS) inverters in parallel configuration, each of the inverters comprising a p-metal oxide semiconductor field effect transistor (MOSFET) at the top and a n- metal oxide semiconductor field effect transistor (MOSFET) at the bottom with their gates connected to a supply voltage and to a gate transmission line and their drains connected to the supply voltage and to a drain transmission line, the drain transmission line and the gate transmission line being connected to each other through a feed back path, the drain transmission line and the gate transmission line each comprising a plurality of coplanar wave guides in series, the number of coplanar wave guide in each of the gate and drain transmission lines being greater than the number of stages of CMOS inverters by a factor of 1, the body of the p-MOSFET being inwardly directed and connected to a forward body bias voltage and the source of the p-MOSFET being connected to the supply voltage and the body of the n-MOSFET being outwardly directed and the body and source of the n-MOSFET being earthed, the gate transmission line further comprising a frequency collector. 8. The high frequency communication network as claimed in claim 7, which comprises a variable capacitance device connected parallel to the drain transmission line or in series with the gate transmission line. 9. The high frequency communication network as claimed in claim 8, wherein the variable capacitance device comprises a pair of metal oxide semiconductor (MOS) varactors. 10. The high frequency communication network as claimed in anyone of claims 7 to 9, wherein each of the p-MOSFETS and n-MOSFETS is 0.18 pm size. 11. The high frequency communication network as claimed in any one of claims 7 to 10, which comprises three stages of CMOS inverters in parallel configuration. 12. The high frequency communication network as claimed in any one of claims 7 to 10, which comprises four stages of CMOS inverters in parallel configuration.

Full Text

FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A tunable distributed voltage controlled oscillator for generating high frequency microwave signals
APPLICANTS
Indian Institute of Technology, Bombay, an autonomous research and educational institution established in India by a special Act of the Parliament of the Republic of India under the Institutes of Technology Act 1961, Powai, Mumbai 400076, Maharashtra, India
INVENTOR
Bhattacharyya Kalyan, Electrical Engineering Department, Indian Institute of
Technology, Bombay, Powai, Mumbai 400076, Maharashtra, India, an Indian
national
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed :

FIELD OF THE INVENTION
This invention relates to a tunable distributed voltage controlled oscillator for
generating high frequency microwave signals.
BACKGROUND OF THE INVENTION
Electrical or electronic communication networks like telecommunication, satellite communication, terrestrial communication, microwave communication or radar communication networks operate on different frequency signals. Microwave radiations have a wide range of frequencies and their application areas differ depending upon their frequencies. For instance, microwave frequency signals of 1 - 2 GHz find application in mobiles. Microwave frequency signals of 2 - 4 GHz are used in heating / cooking applications. High frequency electrical or electronic communication networks like radar or satellite networks or mobile telecommunication backbone networks operate on k band (frequencies of 18 to 27 GHz) and ku band (frequencies of 12 to 18 GHz). Microwave tubes are generally used for generating high frequency microwave signals. Microwave tubes are heavy and bulky and occupy large area and are unwieldy to handle. Besides, they are very expensive and their power consumption is very high.
Distributed voltage oscillators for generating frequency signals are reported. A distributed voltage oscillator comprises n-MOSFETs (metal oxide semiconductor field effect transistors). (Exploiting CMOS Reverse Interconnect Scaling in Multigigahertz Amplifier and Oscillator Design by Bendik Kleveland et ai, IEE Journal of Solid State Circuits, Vol 36 No 10 October 2001). Its power consumption and fabrication cost are high and power output (output signal strength) is low. It

generates a fixed frequency and hence a fixed frequency signal. In order to generate a range of frequency signals corresponding number of oscillators will be required. Cost, power consumption and size and space for occupation of the oscillator are increased because of this also. Distributed voltage controlled oscillators for generating frequencies are also reported. A distributed voltage controlled oscillator also comprises (n-MOSFETs (metal oxide semiconductor field effect transistors). (Silicon Based Distributed Voltage-Controlled Oscillators by Hui Wu et al, IEE Journal of Solid State Circuits, Vol 36 No 3 March 2001). It generates a range of low frequency signals and its power consumption is high and power output is low.
OBJECTS OF THE IVENTION
An object of the invention is to provide a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, which oscillator is economical, compact, light weight, occupies reduced surface area and is easy to handle.
Another object of the invention is to provide a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, which oscillator consumes very low power and gives high power output (output signal strength).
Another object of the invention is to provide a high frequency electrical or electronic communication network comprising a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, which oscillator is

economical, compact, light weight, occupies reduced surface area and is easy to handle.
Another object of the invention is to provide a high frequency electrical or electronic communication network comprising a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, which oscillator consumes very low power and gives high power output (output signal strength).
DETAILED DESCRIPTION OF THE INVENTION
According to the invention there is provided a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, the oscillator comprising a plurality of stages of complimentary metal oxide semiconductor (CMOS) inverters in parallel configuration, each of the inverters comprising a p-metal oxide semiconductor field effect transistor (MOSFET) at the top and a n-metal oxide semiconductor field effect transistor (MOSFET) at the bottom with their gates connected to a supply voltage and to a gate transmission line and their drains connected to the supply voltage and to a drain transmission line, the drain transmission line and the gate transmission line being connected to each other through a feed back path, the drain transmission line and the gate transmission line each comprising a plurality of coplanar wave guides in series, the number of coplanar wave guide in each of the gate and drain transmission lines being greater than the number of stages of CMOS inverters by a factor of 1, the body of the p-MOSFET being inwardly directed and connected to a forward body bias voltage and the source of the p-MOSFET being connected to the supply voltage and the body of the n-MOSFET

being outwardly directed and the body and source of the n-MOSFET being earthed, the gate transmission line further comprising a frequency collector.
According to the invention there is also provided a high frequency electrical or electronic communication network comprising a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, the oscillator comprising a plurality of stages of complimentary metal oxide semiconductor (CMOS) inverters in parallel configuration, each of the inverters comprising a p-metal oxide semiconductor field effect transistor (MOSFET) at the top and a n- metal oxide semiconductor field effect transistor (MOSFET) at the bottom with their gates connected to a supply voltage and to a gate transmission line and their drains connected to the supply voltage and to a drain transmission fine, the drain transmission line and the gate transmission line being connected to each other through a feed back path, the drain transmission line and the gate transmission line each comprising a plurality of coplanar wave guides in series, the number of coplanar wave guide in each of the gate and drain transmission lines being greater than the number of stages of CMOS inverters by a factor of I, the body of the p-MOSFET being inwardly directed and connected to a forward body bias voltage and the source of the p-MOSFET being connected to the supply voltage and the body of the n-MOSFET being outwardly directed and the body and source of the n-MOSFET being earthed, the gate transmission line further comprising a frequency collector.
The following is a detailed description of the invention with reference to the accompanying drawings, in which:

The tunable distributed voltage controlled oscillator 1A as illustrated in Figs 1 and 2 of the accompanying drawings comprises 3 stages of complementary metal oxide semiconductor (CMOS) inverters 2, 3 and 4 in parallel configuration. Each of the inverters comprises a p-metal oxide semiconductor field effect transistor (MOSFET) 5 at the top and a n-metal oxide semiconductor field effect transistor (MOSFET) 6 at the bottom.. The gates 7 and 8 of the transistors are connected to a supply voltage 9 and to a gate transmission line 10, respectively. The drains 11 and 12 of the transistors are connected to the supply voltage 9 and to a drain transmission line 13, respectively. The gate transmission line and drain transmission line are connected to each other through a feed back path 14. The gate transmission line and drain transmission line each comprises four coplanar wave guides (CPW) 15 and 16 in series, respectively. The body 17 of transistor 5 is inwardly directed and connected to a forward body bias (FBB) voltage 18 and the source 19 of transistor 5 is connected to the supply voltage 9. The body 20 of transistor 6 is outwardly directed and the body 20 and source 21 of transistor 6 are earthed. 22 is a frequency collector connected to the gate transmission line. Preferably each of the transistors is 0.18 Mm size. A supply voltage is given to the transistors to keep them in the operative mode. On applying varying FBB voltages to the body nodes of the transistors, correspondingly varying frequency signals are generated in the drains. Varying frequency signals also can be generated by varying the supply voltage. The frequency signals add up in the drain transmission Vine in the forward propagating direction. The frequency signals travel down the gate transmission line through the feed back path and are collected at frequency collector

Fig 1 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to an embodiment of the invention;
Fig 2 is an enlarged view of the portion marked X in Fig 1;
Fig 3 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to another embodiment of the invention;
Fig 4 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to another embodiment of the invention;
Fig 5 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to another embodiment of the invention;
Fig 6 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to another embodiment of the invention; and
Fig 7 is the circuit diagram of a tunable distributed voltage controlled oscillator for generating high frequency microwave signals according to another embodiment of the invention.

The tunable distributed voltage controlled oscillator 1A as illustrated in Figs 1 and 2 of the accompanying drawings comprises 3 stages of complementary metal oxide semiconductor (CMOS) inverters 2, 3 and 4 in parallel configuration. Each of the inverters comprises a p-metal oxide semiconductor field effect transistor (MOSFET) 5 at the top and a n-metal oxide semiconductor field effect transistor (MOSFET) 6 at the bottom. The gates 7 and 8 of the transistors are connected to a supply voltage 9 and to a gate transmission line 10, respectively. The drains 11 and 12 of the transistors are connected to the supply voltage 9 and to a drain transmission line 13, respectively. The gate transmission line and drain transmission line are connected to each other through a feed back path 14. The gate transmission line and drain transmission line each comprises four coplanar wave guides (CPW) IS arvd 16 in series, respectively. The body 17 of transistor 5 is inwardly directed and connected to a forward body bias (FBB) voltage 18 and the source 19 of transistor 5 is connected to the supply voltage 9. The body 20 of transistor 6 is outwardly directed and the body 20 and source 21 of transistor 6 are earthed. 22 is a frequency collector connected to the gate transmission line. Preferably each of the transistors is 0.18 (pm size. A supply voltage is given to the transistors to keep them in the operative mode. On applying varying FBB voltages to the body nodes of the transistors, correspondingly varying frequency signals are generated in the drains. Varying frequency signals also can be generated by varying the supply voltage. The frequency signals add up in the drain transmission line in the forward propagating direction. The frequency signals travel down the gate transmission line through the feed back path and are collected at frequency collector

In the case of the tunable distributed voltage controlled oscillators IB and 1C of Figs 3 and 4 of the accompanying drawings respectively the oscillators comprise a variable capacitance device 23 in series with the gate transmission line and parallel to the drain transmission line, respectively. The varactors are connected to the supply voltage 9. Preferably, the variable capacitance device comprises a pair of metal oxide semiconductors (MOS) varactors. By changing the voltage to the varactors the capacitance of the varactors and hence the capacitance of the oscillators can be varied. Thus by changing both the FBB voltages and the supply voltage to the varactors additional high frequency microwave signals can be generated by the oscillator of Figs 3 and 4. The tunable distributed voltage controlled oscillators of Figs ID, IE and IF, of Figs 5, 6 and 7 of the accompanying drawings include an additional stage of CMOS inverter 24. The oscillators of Figs 5 to 7 are otherwise similar to and function in the same manner as the oscillators of Figs 1 and 2, 3 and 4 respectively. It is understood that the number of stages of CMOS inverters can vary and can be more than 3 or 4 and that the number of (CPWs) in each of the gate and gain transmission lines should be greater than the number of CMOS inverters by a factor 1. Oscillators comprising such configurations of CMOS invertors and (CPWs) are obvious to a person skilled in the art and are to be construed and understood to be within the scope of the invention.
The tunable distributed voltage controlled oscillator of the invention generates high frequency microwave signals in the range of 17.33 to 24.09 GHz. Power consumption by the oscillator is very low as it operates at low voltages in the range of 0.9 to 1.8 volts. The power output (output signal strength) of the oscillator is high in the range of 4.9 to 4.8 dBm (3.1 to 3.05 milliwatts). The oscillator is very compact as the

CMOS inverters used in the invention are miniature in size being of the order of 0.18 urn. Therefore, the oscillator is light weight and occupies reduced surface area and is easy to handle. It is also economical in terms of initial cost and operating cost. The oscillator can be advantageously used in high frequency electrical or electronic communication networks like radar or satellite communication networks or mobile telecommunication backbone networks.
The following examples are illustrative of the invention but not limitative of the scope thereof:
Example 1
Simulation tests were carried out with a typical oscillator of Fig 1. The supply voltage was maintained at 1 .IV and the FBB voltages were varied and the results were as shown in the following Table 1 below:
Table 1

FBB voltage Oscillator
Frequency
(GHz) Power Output (dBm) Phase Noise dBc/Hz (1 MHz
offset)
1.8 V 23.97 0.301 -97.696
1.35 V 23.59 0.827 -99.26
Simulation tests were also carried out with the typical oscillator of Fig 1, where the FBB voltage was maintained at 1.8V and the supply vol results were as shown in the following Table 2:

Table 2

Supply Voltage Oscillator
Frequency
(GHz) Power Output (dBm) Phase Noise dBc/Hz at 1 MHz offset
0.9 V 23.84 -0.8 -96.155
1.0V 23.88 0.2 -96.593
1.1 V 23.97 0.301 -97.696
1.2 V 24.09 -1.0 -95.6
It is seen from the data in Table 1 that with small change of FBB voltage by 0.45V (1.8V to 1.35V), it is possible to achieve a frequency of 380 MHz (23.97 to 23.59 GHz) at low noise level of operation. It is seen from the data in Table 2 that by varying the supply voltage from 0.9V to 1.2 V, it is possible to achieve frequency tuning from 23.84GHz to 24.09GHz. In other words, tuning of frequency of (24.09 -23.84 GHz) = 250MHz is achieved by change of supply voltage by 0.3V (1.2V -0.9V) keeping the body bias voltage constant. It shows that the centre frequency of the oscillator is tunable by 250MHz by changing the supply voltage from 0.9V to 1.2V, In real-life the voltage can be increased up to 1.8V and hence the projected tuning range of centre frequency over the supply voltage is at least 500MHz. The noise level of operation is also very low.
Example 2
Simulation tests were carried out with a typical oscillator of Fig 3 by varying both the
FBB voltage and the varac voltage and the results were as shown in Table 3 below:

Table 3

FBB
Voltage Varac Voltage Oscillator
Frequency
(GHz) Power output
(dBm) Phase noise
dBc/Hz
(1MHz offset)
1.8 V I.8V 23.53 -6.862 -92.26
1.35 V 1.8V 23.14 -6.757 -93.286
1.35 V 1.0 V 23.10 -7.996 -93.2
It is seen from the data in Table 3 that a frequency tuning of 390MHz (23.53-23.14 GHz) is achieved by varying FBB voltage by 0.45V (1.8V to 1.35V). It is also possible to carry out frequency tuning of 40MHz (23.14-23.10 GHz) concurrently by changing varactor bias voltage by 0.8V (1.8V to 1.0V). Total tuning by FBB voltage and series varactors is 430MHz (23.53 to 23.10 GHz). The noise level of operation is also very low.
Example 3
Simulation tests were carried out with a typical oscillator of Fig 4 by varying both the FBB voltage and the varac voltage and the results were as shown in Table 4 below:
Table 4

FBB
Voltage Varac Voltage Oscillator
frequency
(GHz) Power output (dBm) Phase Noise
dBc/Hz (1MHz
offset)
1.8 V 0.9 V 22.79 0.622 -99,06
1.35 V 0.9 V 22.45 1.095 -99.968
1.35 V 1.8 V 22.11 0.56 -98.959
It is seen from the data in Table 4 that a frequency tuning of 340MHz (22,79 - 22. 45 GHz) is achieved by varying FBB of voltage by 0.45V (1.8V to 1.35V). It is also possible to carry out frequency tuning of 340MHz (22.45-22.11 GHz) concurrently by changing varactor bias voltage by 0.9V (0.9V to 1.8V). Total tuning by FBB voltage

and parallel varactors is 680MHz (22.79 to 22.11 GHz). The noise level of operation is also very low.
Example 4
Simulation tests were carried out with a typical oscillator of Fig 5 by keeping the supply voltage at I.IV and varying the FBB voltage and the results were as shown in Table 5 below:
Table 5

FBB Voltage Oscillator
frequency
(GHz) Power (dBm) Phase Noise
dBc/Hz at 1 MHz
offset
1.8 V 18.64 4.918 -102.407
1.35 V 18.37 4.842 -103.46
Simulation tests were also carried out with a typical oscillator of Fig 5 by keeping the FBB voltage at 1.8V and varying the supply voltage and the results were shown in Table 6 below:

Table 6

Supply Voltage Oscillator
Frequency
(GHz) Power (dBm) Phase Noise dBc/Hz (1 MHz
offset)
0.9 V 18.44 3.822 -98.622
1.0V 18.54 4.362 -101.2
1.1 V 18.64 4.918 -102.407
1.2 V 18.73 4.836 -100.14
1.3 V 18.83 4.887 -94.872
1.4 V 18.93 4.841 -89.362
1.5 V 19.02 4.708 -87.307
1.6 V 19.08 4.524 -92.307
1.7 V 19.11 4.302 -92.157
It is seen from the data in Table 5 that with small change of FBB voltage by 0.45V (1.8V to 1.35V), it is possible to achieve a frequency change of 270 MHz (18.64 to 18.37 GHz) at low noise level of operation. It is seen from the data in Table 6 that it is possible to achieve frequency tuning of 18.44 GHz to 19.11 -GHz by varying supply voltage from 0.9 to 1.7V ie a tuning of frequency (19.11 - 18.44 GHz = 670 MHz by change of supply voltage by 0.8V (1.7V - 0.9V).
Example 5
Simulation tests were carried out with a typical oscillator of Fig 6 by changing both
the FBB voltage and varac voltage and the results were as shown in Table 7 below:

Table 7

Body Bias Varac Bias Oscillator
Frequency
(GHz) Power output (dBm) Phase Noise
dBc/Hz (1MHz offset)
1.8V 1.8V 18.09 -4.404 -100.4
1.35 V 1.8 V 17.82 -4.621 -101.49
1.35 V 1.0V 17.79 -5.817 -100.90
It is seen from the data in Table 7 that frequency tuning of 270MHz (18.09 to 17.82 GHz) is achieved by varying FBB voltage by0.45V (1.8V to 1.35V). Frequency tuning of 30 MHz (17.82 - 17.79 GHz) is concurrently achieved by series varactors by changing the varactor bias by 0.8V (1.8V to 1.0V). Total tuning by FBB and series varactors is 300 MHz (18.09 to 17.79 GHz). The oscillator thus performs in both K and Ku bands. The noise level of operation is also very low.
Example 6
Simulation tests were carried out with a typical oscillator of Fig 7 by changing both
the FBB voltage and varac voltage and the results were as shown in Table 8 below:
Table 8

FBB
voltage Varac voltage Oscillator
Frequency
GHz Power (dBm) Phase Noise dBc/Hz at 1MHz
offset
1.8 0.9 17.77 4.845 -101.491
1.35 0.9 17.53 4.821 -102.037
1.35 1.8 17.33 4.681 -103.067
It is seen from the data in Table 8 that a frequency tuning of 240MHz (17.77 -17.53GHz) is achieved by varying FBB voltage by 0.45V (1.8V to 1.35V). It is also possible to achieve frequency tuning of 200MHz (17.53-17.33GHz) concurrently by changing varactor bias by 0.9V (1.8V to 0.9V). Total tuning by FBB and parallel

varactor is 440MHz (17.77 to 17.33 GHz). The noise level of operation is also very low.
Example 7
The oscillators of the invention were also found to emit very low power in 2nd and 3rd harmonics frequencies as can be seen from the typical examples in Tables 9 and 10 below. Table 9 gives harmonics of the typical oscillator of Fig 4 and Table 10 gives harmonics of the typical oscillator of Fig 7.
Table 9

FBB Voltage Varac Voltage Harmonics Oscillator
Frequency
(GHz) Power emitted (dBm)
1.8 0.9 1 22.79 0.622

2 45.57 -23.387

3 68.36 -46.094
1.35 0.9 1 22.45 1.095

2 44.90 -24.539

3 67.35 -45.075
1.35 1.8 1 22.11 0.56

2 44.22 -26.565

3 66.33 -47.013

Table 10

FBB Voltage Varac Voltage Harmonics Oscillator
Frequency
(GHz) Power emitted (dBm)
1.8 1.8 1 18.09 -4.404

2 36.18 -21.714

3 54.27 -27.447
1,35 1.8 1 17.82 -4.621

2 35.63 -23.437

3 53.45 -29.247
1.35 1.2 1 17.79 -5.817

2 35.58 -23.037

3 53.37 -38.437

We Claim :
1. A tunable distributed voltage controlled oscillator for generating high
frequency microwave signals, the oscillator comprising a plurality of stages of
complimentary metal oxide semiconductor (CMOS) inverters in parallel
configuration, each of the inverters comprising a p-metal oxide semiconductor field
effect transistor (MOSFET) at the top and a n-metal oxide semiconductor field effect
transistor (MOSFET) at the bottom with their gates connected to a supply voltage and
to a gate transmission line and their drains connected to the supply voltage and to a
drain transmission line, the drain transmission line and the gate transmission line
being connected to each other through a feed back path, the drain transmission line
and the gate transmission line each comprising a plurality of coplanar wave guides in
series, the number of coplanar wave guide in each of the gate and drain transmission
lines being greater than the number of stages of CMOS inverters by a factor of 1, the
body of the p-MOSFET being inwardly directed and connected to a forward body bias
voltage and the source of the p-MOSFET being connected to the supply voltage and
the body of the n-MOSFET being outwardly directed and the body and source of the
n-MOSFET being earthed, the gate transmission line further comprising a frequency
collector.
2. The tunable oscillator as claimed in claim 1, which comprises a variable
capacitance device connected parallel to the drain transmission line or in series with
the gate transmission line.

3. The tunable oscillator as claimed in claim 2, wherein the variable capacitance device comprises a pair of metal oxide semiconductor (MOS) varactors.
4. The tunable oscillator as claimed in anyone of claims 1 to 3, wherein each of the p-MOSFETS and n-MOSFETS is 0.18 pm size.
5. The tunable oscillator as claimed in anyone of claims 1 to 4, which comprises three stages of CMOS inverters in parallel configuration.
6. The tunable oscillator as claimed in any one of claims 1 to 4, which comprises four stages of CMOS inverters in parallel configuration.
7. A high frequency electrical or electronic communication network comprising a tunable distributed voltage controlled oscillator for generating high frequency microwave signals, the oscillator comprising a plurality of stages of complimentary metal oxide semiconductor (CMOS) inverters in parallel configuration, each of the inverters comprising a p-metal oxide semiconductor field effect transistor (MOSFET) at the top and a n- metal oxide semiconductor field effect transistor (MOSFET) at the bottom with their gates connected to a supply voltage and to a gate transmission line and their drains connected to the supply voltage and to a drain transmission line, the drain transmission line and the gate transmission line being connected to each other through a feed back path, the drain transmission line and the gate transmission line each comprising a plurality of coplanar wave guides in series, the number of coplanar wave guide in each of the gate and drain transmission lines being greater than the number of stages of CMOS inverters by a factor of 1, the body of the p-MOSFET

being inwardly directed and connected to a forward body bias voltage and the source of the p-MOSFET being connected to the supply voltage and the body of the n-MOSFET being outwardly directed and the body and source of the n-MOSFET being earthed, the gate transmission line further comprising a frequency collector.
8. The high frequency communication network as claimed in claim 7, which comprises a variable capacitance device connected parallel to the drain transmission line or in series with the gate transmission line.
9. The high frequency communication network as claimed in claim 8, wherein the variable capacitance device comprises a pair of metal oxide semiconductor (MOS) varactors.
10. The high frequency communication network as claimed in anyone of claims 7 to 9, wherein each of the p-MOSFETS and n-MOSFETS is 0.18 pm size.
11. The high frequency communication network as claimed in any one of claims 7 to 10, which comprises three stages of CMOS inverters in parallel configuration.
12. The high frequency communication network as claimed in any one of claims 7 to 10, which comprises four stages of CMOS inverters in parallel configuration.

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Patent Number

269540

Indian Patent Application Number

81/MUM/2010

PG Journal Number

44/2015

Publication Date

30-Oct-2015

Grant Date

27-Oct-2015

Date of Filing

11-Jan-2010

Name of Patentee

INDIAN INSTITUTE OF TECHNOLOGY, BOMBAY

Applicant Address

POWAI, MUMBAI 400076, MAHARASHTRA, INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	BHATTACHARYYA KALYAN	ELECTRICAL ENGINEERING DEPARTMENT, INDIAN INSTITUTE OF TECHNOLOGY, BOMBAY, POWAI, MUMBAI 400076, MAHARASHTRA, INDIA

PCT International Classification Number

H03B1/00,H03B5/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA