Millimeter-Wave (W-Band) Quartz Image Guide Gunn Oscillator

Dielectric image-guide Gunn oscillator using fused quartz as the guide material has been investigated at frequencies around 94 GHz. Computer-controlled CO/sub 2/ laser cutting of quartz to the designed image-guide patterns has also been achieved. A resonant disk and pin bias circuit was used to tune the oscillator to an output power of 5 mW at the oscillation frequency of 94.2 GHz. An electronic frequency tuning of 350 MHz was measured with the oscillation characteristics similar to waveguide cavity oscillators. By varying the bias circuit disk and pin parameters, the Gunn-oscillator tuning characteristics have also been recorded for the future circuit performance optimization.     

High-performance second-harmonic operation W-band GaAsGunn diodes

High output power performance and DC-to-RF conversion efficiency of second-harmonic-operation W-band (75-110 GHz) GaAs Gunn diodes is reported. Output powers of 96 and 48 mW at 94 and 103 GHz, respectively, with a DC-to-Rf conversion efficiency of 2.7 and 2.3 percent, have been achieved using single-diode GaAs Gunn oscillators. The operation of these diodes requires 2 to 4 W of DC power consumption     

Experimental investigation of millimeter wave Gunn oscillator circuits in circular waveguides

Millimeter wave Gunn oscillator circuits using circular waveguides for 33–50 GHz and 75–110 GHz frequency bands are described. These oscillators are simpler to construct at millimeter wavelengths compared to the conventional rectangular waveguide circuits. The effect of various circuit parameters on the oscillator frequency and output power has been experimentally studied. The CW power and mechanical tuning range obtained from the circular waveguide Gunn oscillators are found to be comparable and sometimes even better than those obtained with conventional rectangular waveguide circuits using the same Gunn device.     

Waveguide/resonant-disc circuits for millimetre-wave devices

Bias circuits using resonant discs have been employed for millimetre-wave transferred-electron (TE) diodes operating at their second or third harmonic frequencies in the V (50?75 GHz) and W (75?110 GHz) bands. It is shown that this type of circuit exhibits resonances at frequencies in the lower millimetre-wave range, corresponding to the fundamental oscillation frequency of diodes typically used. In addition, the circuit provides efficient coupling to the waveguide circuit at the higher (harmonic) operating frequency. By tuning the fundamental oscillation frequency of a number of resonant discs, the power-frequency spectrum of the TE device can be determined, which is demonstrated for a device with its maximum third-harmonic power output at 94 GHz.     

C波段20W脉冲耿振荡器

完整的脉冲耿振荡器包括脉冲耿二极管、微波电路及脉冲调制器。本文主要描述了该振荡器的结构和设计原理,并给出了C波段脉冲耿振荡器的研制结果:在4～6GHz,得到的最大脉冲功率为22W,最佳效率为5％,最大工作比为1％。     

Simulation Study of Harmonic Oscillators

In the last few years, the operating modes of Gunn oscillators for frequencies above 60 GHz have been discussed controversially. In this context, a general theoretical circuit model for oscillators operating in the fundamental and in the second-harmonic modes is studied. The model employs a simple cubic I - V characteristic of the active element and separate embedding circuits for the fundamental and second-harmonic frequencies. The current and voltage waveforms of both modes are contrasted. The oscillator source impedances and the external Q of the second-harmonic mode oscillator are calculated.     

Oscillators and amplifiers in integrated E-plane technique

An overview is presented of solid-state oscillators and amplifiers realized in E-plane technology. The circuit topology, basic design procedures, and performance characteristics are described and compared. Gunn oscillators, IMPATT oscillators, transistor oscillators, injection-locked Gunn oscillators, and transistor amplifiers are surveyed. Gunn and transistor oscillators have been realized successfully for frequencies from 10 to 110 GHz, thus covering almost the entire frequency range suitable for E-plane technology. IMPATT oscillators are difficult to design and to reproduce in quasi-planar form because of the high impedance ratio that must be overcome by the circuit. E-plane FET amplifiers have been built for frequencies up to 60 GHz     

Gunn-diode oscillator at 95 GHz

The results of Gunn-diode-oscillator development at 90 to 94 GHz are reported, along with a discussion of the devices and circuit used. The best performance obtained was 25 mW output power (at 30°C heatsink temperature) with a d.c.-to-r.f. conversion efficiency of 0.6% at an operating frequency of 93.7 GHz.     

High-performance millimetre-wave suspended stripline Gunn VCO

A novel millimetre-wave integrated circuit Gunn voltagecontrolled oscillator (VCO) has been developed with high output power using suspended stripline. An output power of 100 to 150mW has been achieved at frequencies between 33 and 42 GHz. A varactor diode was mounted in alignment and in close proximity to the Gunn diode to achieve an electronic tuning range of 300 MHz     

Simple integrated circuit with Gunn devices

This letter describes the structure and electrical performance of a simple integrated digital circuit on GaAs using Gunn devices, which is capable of operating at up to 2 Gbit/s. A directed transfer of domain pulses within the circuit, which is almost free of reactive effects, is achieved by employing Schottky-barrier diodes.     

Planar FET oscillators using periodic microstrip patch antennas

An integrated oscillator/antenna is presented that uses a single microstrip leaky-wave structure as both the resonant and the radiating element. This resonant antenna is connected to a GaAs metal-semiconductor field-effect transistor which acts as the negative resistance element in the oscillator circuit. This type of oscillator is similar in its operating principle to one reported using Gunn diodes and a periodically notched dielectric image guide. This circuit exhibits the high DC-RF conversion efficiency that is typical of field-effect transistor oscillators. The planar circuit is simple and inexpensive to construct, occupies a small volume, and can conform to different surface profiles. Such circuits are suitable for use in millimeter-wave systems as well as at microwave frequencies. A design procedure is given, and the performance of X-band prototype circuits is reported. Prototype circuits showed a 9 dB isotropic conversion gain and 40 MHz tuning range at 9.5 GHz     

Millimeter-wave Gunn oscillator in series operation

The feasibility of series operation of a Gunn-diode oscillator in a millimeter-wave range is demonstrated. Oscillator output power and its dc-to-RF conversion efficiency can both be increased substantially by operating two Gunn diodes in series. Output power from two diodes in series operation is higher than twice the output power obtained from one individual diode. We report that the pulsed output power from two GaAs Gunn diodes in series operation reaches 4.4 W at a frequency of 33.2 GHz.     

Linear microwave amplification with Gunn oscillators

Linear microwave amplifiers with continuous power outputs of 100 mW have been constructed utilizing the frequency-independent negative conductance observed externally in Gunn oscillators. This negative conductance is exhibited only in samples containing propagating dipole layers, in other words,n_{0} . Lmust be larger than 10¹²cm^-2for n-GaAs. The output power obtainable from this amplifier is substantially larger than that from a subcritically doped GaAs amplifier (n_{0} . L < 10^{12}cm^-2) becausen_{0} . Lcan be increased. Power output and efficiency are discussed in terms of n0andL. The upper-frequency limit for amplification is determined by the time the domain takes to readjust itself after a change of external voltage which leads to an upper limit for thef. Lproduct (about 10⁸cm/s). The essential feature of the amplifier circuit is to provide both a short circuit at the Gunn oscillation frequency and a broadband circuit at the signal frequency. An average gain of 3 dB was exhibited from 5.5 GHz to 6.5 GHz. Gain compression of 1 dB occurred at 60 mW output power with 9 dB gain, while the noise figure was about 19 dB.     

Ku波段脉冲耿氏振荡器

文章描述了脉冲耿氏管、微波电路和脉冲调制器的结构和设计原则;给出了Ku波段脉冲耿氏振荡器的研制结果:在13～15GHz范围内,脉冲功率大于5W,工作比≤1％,最大效率为5％。     

Varactor-tuned integrated Gunn oscillators

Electronic tuning of Gunn diodes in hybrid integrated circuits has been studied. Microstrip transmission lines were used to form resonant circuits into which a Gunn diode and a varactor diode were mounted to provide the microwave power and frequency tuning, respectively. Basically, two types of circuits have been investigated. The first is a half-wavelength open-circuited microstrip `cavity' with this transmission line and the varactor diode attached between the end of the cavity and an RF ground. The second is a lumped LC circuit in which the inductance of a short high-impedance microstrip line is resonated with the lumped capacitance of the varactor diode. The latter circuit provides a tuning range of over 10 percent at 7.5 GHz. The power output varies within 2 dB in the tuning range.     

A low-power 72.8-GHz static frequency divider in AlInAs/InGaAs HBTtechnology

We report a 72.8-GHz fully static frequency divider in AlInAs/InGaAs HBT IC technology. The CML divider operates with a 350-mV logic swing at less than 0-dBm input power up to a maximum clock rate of 63 GHz and requires 8.6 dBm of input power at the maximum clock rate of 72.8 GHz. Power dissipation per flip-flop is 55 mW with a 3.1-V power supply. To our knowledge, this is the highest frequency of operation for a static divider in any technology. The power-delay product of 94 fJ/gate is the lowest power-delay product for a circuit operating above 50 GHz in any technology. A low-power divider on the same substrate operates at 36 GHz with 6.9 mW of dissipated power per flip-flop with a 3.1-V supply. The power delay of 24 fJ/gate is, to our knowledge, the lowest power-delay product for a static divider operating above 30 GHz in any technology. We briefly review the requirements for benchmarking a logic family and examine the historical trend of maximum clock rate in high-speed circuit technology     

Optimized design of quasi-optical source-array of solid state source power combiner at frequency 100 GHz

It is determined for the structure of the source-array located in inner surface of input quasi-optical resonator operating at frequency 100GHz using Type WT5731 GaAs Gunn diodes made in P.R. China (fundamental frequency 50 GHz). An adaptable phase coupling has been achieved and RF output power exceeded the sum of the individual diode outputs by from three to seven times.     

High-performance oscillators and power combiners with InP Gunn devices at 260-330 GHz

InP Gunn devices with graded doping profiles were evaluated for second-harmonic power extraction above 260 GHz. The best devices generated radio frequency(RF) output power levels of 3.9 mW at 275 GHz, 4.8 mW at 282 GHz, 3.7 mW at 297 GHz, 1.6 mW at 329 GHz, and 0.7 mW at 333 GHz with corresponding dc-to-RF conversion efficiencies of 0.24%, 0.31%, 0.32%, 0.19%, and 0.07%. The highest observed second-harmonic frequency was 345 GHz. Two devices each in an in-line power combining circuit generated 6.1 mW at 285 GHz and 2.7 mW at 316 GHz with combining efficiencies of more than 65%.     

High-efficiency series operation of Gunn devices

Successful series operation of two Gunn devices, differing by about 10% in threshold current, has been achieved at X band (8.5?12GHz). The devices were mounted in a resonant cavity and biased to approximately six times the threshold voltage of a single device before both became active. At that point, the output power of the series combination was nearly equal to the sum of the powers observed previously for each device operating alone at its measured bias voltage. For one particular set of diodes, the observed efficiency (for series operation with N/f = 1.3 × 105 s/cm3) was 28.2% at 8.3GHz with 3.4W of peak pulsed power output. This is the highest efficiency ever reported for Gunn devices at such frequencies.