变容二极管调谐体效应振荡器的CAD

本文建立了一种新的 Gunn VCO 的电路模型,计算了 Gunn 管和变容二极管之间的径向盘耦合电容。首次利用谐波平衡法对 Gunn VCO 进行了非线性分析,设计并制作了一 Ka 波段混合集成 Gunn VCO,实验结果与 CAD 结果进行了比较,证明了该种电路模型与分析方法的有效性。此外利用该分析程序研究了Gunn 管和变容二极管之间的耦合与调谐带宽的关系。在分析的基础上,利用线性拟合误差函数作为 Gunn VCO 频率调谐线性度的优化目标函数,对 VCO 的频率调谐特性进行了优化,确定了此种电路在最佳线性调谐时 PN 结幂指数γ的值,从而在理论上对满足线性调谐的变容二极管提出了要求。     

Novel varactor-tuned millimetre-wave Gunn oscillator

A novel design of varactor-tuned millimetre-wave second-harmonic Gunn oscillator is reported in which a varactor is mounted in a secondary cavity resonant at the fundamental frequency of the Gunn diode. This has the advantage that the varactor does not significantly load the Gunn diode at the output second-harmonic frequency, and enables the oscillator to produce the maximum possible output power from the diode while still offering varactor tuning and high Q.     

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.     

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     

Characteristics of a GaN-based Gunn diode for THz signal generation

A generalized large-signal computer simulation program for a Gunn oscillator has been developed.The properties of a Gunn diode oscillator based on the widely explored GaN,are investigated using the dev...     

Varactor-tuned X band Gunn oscillator using lumped thin-film circuits

The operation of a varactor-tuned oscillator using an unen-capsulated Gunn and varactor diode is described, where the associated circuit consists of lumped elements fabricated using thin-film techniques. Depending on the GaAs material, the oscillator provides output powers greater than 10 mW and a tunable 3 dB bandwidth in excess of 1 GHz. At zero varactor bias, the frequency can be set in the 7?12 GHz range. Satisfactory correlation with the theory is demonstrated.     

W-band monolithic frequency doubler using vertical GaAs varactor diode with n/sup +/ buried layer

A W-band monolithic frequency doubler was designed and fabricated using a vertical GaAs varactor diode that has an n/sup +/ buried layer and uses a mesa isolation process. An output power of 30 mW was obtained from this chip at 93 GHz with a conversation efficiency of 12%. This is believed to be the first reported W-band monolithic varactor diode frequency doubler.<>     

The effect of operating parameters and oscillator characteristics upon the phase angle between a locked X-band Gunn oscillator and its locking signal

Experiments have been carried out to measure the phase angle between a locked negative-resistance (Gunn) oscillator and its locking oscillator. Phase angle has been measured as a function of ambient temperature, oscillator bias voltage, locking power, and the voltage applied to a varactor tuning diode coupled into the locked oscillator. Results indicate that given a knowledge of the oscillator characteristics and the operating conditions, it is possible to predict, with reasonable accuracy, the phase of the locked oscillator. The relative merits of various methods of phase control are discussed and it is concluded that the best method is to use a varactor diode coupled into the negative-resistance oscillator.     

Low noise GaAs varactor and mixer diodes prepared by molecular beam epitaxy

Schottky-barrier varactor and mixer diodes have been made from Ge-doped GaAs layers grown by molecular beam epitaxy. A microstrip parametric amplifier circuit incorporating a hyperabrupt varactor diode has given a noise temperature of 120 K and bandwidth of 180 MHz at 15 dB gain when pumped at 34 GHz, and a mixer diode mounted in a cryogenic receiver circuit had an s.s.b. noise temperature of 180 K at 90 GHz.     

Millimeter wave pulsed gunn oscillator for low chirp radar application at W-Band

Pulsed Gunn oscillator at 94 GHz has been developed using GaAs CW Gunn diode, by choosing a proper operating point and resonant circuit. Peak power output of 25 mw at 94 GHz with a pulse width of 2 microseconds and duty factor of 2% is achieved. Bias circuit oscillations are suppressed by rising the operating voltage alongwith other circuit considerations.     

U-band shield suspended-stripline Gunn DRO and VCO

A millimeter-wave IC dielectric resonator oscillator (DRO) is proposed. Equations that give the resonant frequency of the dielectric resonator DR in suspended stripline (SSL) are derived. A U-band voltage-controlled oscillator (VCO) with varactor tuning also has been developed. The Gunn diode and varactor used in both of the oscillators are commercially available packaged devices. Restrictions on the performance of the oscillators imposed by packaged and mounted networks and the self-characteristics of the solid-state devices have been analyzed. An electronic tuning range greater than 1000 MHz with an output power exceeding 15 dBm across the bandwidth in the 53-GHz region has been realized for the SSL VCO. An SSL DRO with an output power of more than 17 dBm and a mechanical tuning range of 1.5 GHz in the 54-GHz region has been achieved     

GaAs W-band IMPATT diodes for very low-noise oscillators

W-band single-drift flat-profile IMPATT diodes were fabricated from GaAs MBE material and tested in a full-height waveguide resonant cavity with resonant cap. A quasi-optical parabolic Fabry-Perot resonator was used to determine the FM noise of the GaAs IMPATT oscillator. With a minimum noise measure of 20 dB at power levels around 20 mW, IMPATT diode oscillators can compete well with oscillators using Gunn devices. The (N/C)/sub FM/=-82 dBc measured at 100 kHz frequency off-carrier and at Q/sub EX/=95 is comparable to the value obtained from Gunn devices. The maximum available output power of 270 mW, however, markedly exceeds that of Gunn oscillators.<>     

8mm GaAs Gunn稳态功率放大器

报导了以商用ＧａＡｓＧｕｎｎ氏振荡管（超临界掺杂Ｇｕｎｎ二极管）研制稳态型功率放大器的设计方法和研制结果。提出了放大器宽温不稳定的解决方法。单管单级放大器，增益大于１０ｄＢ，带宽大于２ＧＨｚ（３３～３５ＧＨｚ），最大输出功率２００ｍｗ，能在－４０～＋５５℃内稳定工作，全温增益变化小于０．５ｄＢ，带内波纹小于０．５ｄＢ。可靠性高。     

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, graded AlGaAs injector, GaAs Gunn diodes at 94GHz

The advantages of using AlGaAs layers of graded Al composition to engineer the cathode of a GaAs Gunn diode are discussed. The specific target of high power operation (68 mW at room temperature) at 94 GHz over a wide range (>1.4 V) of voltage bias has been achieved. Other advantages of the cathode structure are briefly discussed     

V波段变容管三倍频器

设计制作了一个从22.8GHz到68.4GHz的封装型变容管三倍频器,这是目前报导的用封装型变容管所达到的最高频率。该倍频器在结构上实现了空闲回路独立可调,从而提高了倍频效率。当频率为22.8GHz而输入功率为47mW时,最大三次谐波输出为4.9mW,最大倍频效率为10.4％,输出频率至少在2GHz的范围内倍频效率不低于7％。     

A Novel SIW-Based Planar W-Band GaAs Gunn Harmonic Oscillator

Based on the substrate integrated waveguide (SIW) technology, a novel W-band low phase noise GaAs Gunn planar harmonic oscillator is developed in this paper. The technique of harmonic extraction from Gunn diodes and SIW resonant cavity structures are discussed in detail. Due to the high quality factor and planar structure of the SIW cavity resonator, the oscillator is characterized by some advantages such as low phase noise, small size, low cost and planar integration. The measured phase noise is −108.56 dBc/Hz at 1 MHz offset and the output power is more than 9 dBm at 94.78 GHz. A 300 MHz of linear tuning range with power fluctuation less than 1.5 dB is observed when the Gunn diode is biased from 4 to 5.3 V.     

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.     

GaAs varactors for linear tuning characteristics

A GaAs u.h.f. varactor diode featuring linear tuning characteristics over part of its tuning range (450?750 MHz) is reported. The packaged diode has a series resistance of 270 m? at 600 MHz, with 95 m? due to the GaAs epitaxial layer. The design of the diode is presented together with technological details of its construction.