FET基波和谐波振荡器的大信号设计

本文根据测出的FET的小信号S参数和静态,I-V特性建立了场效应管的大信号模型,然后应用谐波平衡法对FET基波和谐波振荡器进行了分析和优化设计,得到了振荡器稳态时的电流值。并采用一种简化的CAD方法求出了最佳功率输出时的外电路参数。在此基础上,研制了基波和Q波段、二次谐波振荡器。实验结果与理论分析基本一致。     

Single-Gate MESFET Frequency Doublers

A simple analytic model of the FET frequency doubler is used to determine the relative contributions of the various nonlinearities to harmonic generation. FET doubler conversion gain and its variation with frequency relative to the fundamental frequency available gain is also estimated. Large-signal computer simulations are used to determine the validity of the analytic model and provide further information on conversion gain and its frequency dependence. The analytic and computer predictions are compared with experimental measurements on a 4- to 8-GHz single-gate FET frequency doubler.     

GaAs FET demodulator and down-convertor for optical-microwave links

A single-gate GaAs FET is utilised to simultaneously perform the photodetection and down-conversion functions of an optical-microwave link receiver, with the transistor supplying its own local oscillator signal through self-oscillation and harmonic generation. Operation up through 89 GHz is demonstrated.     

A GaN differential oscillator with improved harmonic performance

The first AlGaN/GaN HEMT based differential oscillator is reported. The MMIC oscillates at a frequency of 4.16 GHz and provides 22.9 dBm of power from one side at a biasing of V/sub gs/-1 V and V/sub ds/20 V. The HEMTs each have a 0.7 /spl mu/m/spl times/200 /spl mu/m gate. The second harmonic is 45 dB below the carrier and the third harmonic is more than 70 dB below the carrier. To our knowledge, this is the best reported harmonic performance for a GaN oscillator. The oscillator efficiency is between 4% and 9.4% depending on bias. The measured phase noise is -86.3 dBc and -115.7 dBc at offsets of 100 kHz and 1 MHz respectively. The phase noise at a 1 MHz offset is similar to the noise performance of FET based differential oscillators in other technologies.     

Phase-locked millimeter-wave two-port second-harmonic Gunnoscillators

Two-port harmonic oscillators have been developed which are suitable for voltage-controlled-oscillator (VCO) operation in frequency stabilized systems. Two oscillator designs are presented. The first has a fundamental frequency cavity located above the harmonic output cavity and the fundamental is coupled by means of the Gunn device bias-line filter. The second design is an in-line structure which uses a waveguide taper as the filter element separating the fundamental and harmonic frequency components. The latter design is a translation of the first oscillator concept onto a single plane, so that the prospect of an integrated monolithic version is conceivable. The performance of the oscillators is discussed, and a demonstration of their use in a heterodyne phase-locked loop control system is presented     

Novel oscillator incorporating a compact microstrip resonant cell

A novel transistor oscillator incorporating a compact microstrip resonant cell (CMRC) as its terminating resonance is proposed. Adjusting the dimensions of the cell, it is possible that the fundamental frequency can be positively fed back and the second harmonic negatively fed back at the input port of the oscillator. The fundamental output is enhanced with the second harmonic being suppressed. The output power of the proposed CMRC oscillator is 14.7 dBm at 2.5 GHz with 27.1 dB rejection of the second harmonic, outperforming the conventional microstrip termination with a 40% size reduction     

脉冲振荡器的包络仿真

本文阐述了包络仿真的基本原理及其应用。以脉冲振荡器的ＣＡＤ为例,为脉冲振荡器分别进行谐波平衡仿真和包络仿真,列出了仿真结果,并对脉冲振荡器输出信号进行数学分析。将仿真与分析的结果进行对照,从而阐明了包络仿真在有关复杂信号的微波电路优化设计和仿真中的作用。     

K波段介质谐振器稳频GaAs FET谐波振荡器

本文对介质谐振器稳频GaAs FET谐波振荡器进行了研究;分析了场效应管中的非线性源产生二次谐波分量的情况,利用两种不同类型的场效应管设计制作了两个介质谐振器稳频场效应管谐波振荡器,在22GHz和18GHz分别得到了5.4mW和305mW的二次谐波功率。     

Extraction Technique of Differential Second Harmonic Output in CMOS LC VCO

A technique to extract differential second harmonic output signals in a CMOS LC voltage-controlled oscillator (VCO) is introduced. In a cross-coupled n-type field effect transistor (NFET) and p-channel field effect transistor (PFET) VCO topology, the upper and lower common source nodes of the FET pairs can provide well-balanced differential second harmonic output by resonating the impedances at the common source nodes and operating the VCO in the voltage-limited regime. The idea is verified experimentally by implementing a 5.6-GHz CMOS VCO having a tunable impedance element at the common source node. The error signal power between the differential signals is measured to be -70dBm when properly tuned, which indicates almost perfect differentiality of the second harmonic output signals     

A feedback model of millimeter wave harmonic oscillators and its application

In this paper a feedback model of second harmonic oscillators is developed. By using describing functions of nonlinearity of active devices, the performances of second harmonic oscillators are studied. Frequency dependence of I–V characteristics of active element are taken into account. The ratio of maximum output power of second harmonic to fundamental is given. The maximum harmonic locking bandwidth of injected harmonic oscillator is derived. The theoretical prediction is compared with experimental results.     

多族谐波信号估计的子空间匹配投影算法

该文根据子空间匹配投影分解算法,将信号自适应地分解在谐波子空间上,得到一种多族谐波信号参数估计的方法。这种方法利用插值FFT算法和谐波参数的先验信息,能分离基频或谐波频率结构较为紧密的不同族谐波分量,谐波频率估计精度高。仿真表明,这种新方法能准确地估计基频频率、谐波频率和阶数,对随机相位抖动也不敏感;用于分析实船噪声也准确反映了船舶辐射噪声功率谱的线谱规律和特点,较好地揭示了船舶的螺旋桨现场实际运行状况,是一种很有价值的多谐波参数估计方法。     

A minaturized broad-band MMIC frequency doubler

A miniaturized broadband balanced MMIC (monolithic microwave integrated circuit) frequency double, composed of a common-gate FET and a common-source FET directly connected to each drain electrode, has been proposed and demonstrated. The doubler is designed and fabricated as a miniaturized function module using a conventional two-gate FET configuration, active trapping, and active impedance matching. The doubler design has been performed through phase error estimation, gate width optimization, and gate-source voltage optimization. The phase error estimation in a nonlinear condition has eliminated phase error compensation circuits. The fabricated chip size is only 0.5 mm×0.5 mm, which is about 1/10 the area of previously reported doublers. A conversion loss of 8-10 dB, a fundamental frequency suppression better than 17 dB, and an input return loss better than 8 dB are obtained in the output frequency range from 6 to 16 GHz. The broadband doubler as a miniaturized MMIC function module can be applicable to small-size oscillator MMICs and multifunction MMICs     

基波注入锁定谐波耿氏振荡器研究

本文基于同步振荡器的非线性模型，导出了基波注入锁定二次谐波耿氏振荡器的锁定带宽表达式，完成了三毫米波段第二次谐波振荡器的基波注入锁定实验，理论分析与实验结果吻合。     

匹配电路谐波特性对功率放大器性能的影响

用 HP EESOF Series IV软件的负载牵引法对功率放大器进行分析 ,给出了匹配电路的基波特性及谐波特性对功率放大器性能的负载牵引结果 ,提出了功率放大器匹配电路谐波设计的思想 ,并给出了设计实例     

A GaAs MESFET Oscillator Quasi-Linear Design Method

A simplified quasi-linear method is proposed to design a GaAs MESFET oscillator. By expressing the generated power P/sub gen/ as a function of FET gate and drain RF voltages, it is possible to maximize P/sub gen/ under the limiting conditions on intrinsic FET terminal voltage amplitudes. The feedback circuit elements to realize a GaAs MESFET oscillator are derived. An X-band GaAs MESFET oscillator was designed by the quasi-linear method and was fabricated by using microwave integrated-circuit technology.     

Design and Performance of X-Band Oscillators with GaAs Schottky-Gate Field-Effect Transistors

The circuit construction and design of an X-band oscillator with a GaAs Schottky-gate FET have been studied. The oscillation characteristics including stability and noise performance have been examined in order to clarify the position of a GaAs FET as a microwave solid-state oscillator device. The experiments have revealed that 1) the GaAs FET simultaneously possesses the most desirable features of both Gunn and IMPATT oscillators, i.e., low bias voltage operation and fairly high efficiency, and 2) it is situated between Gunn and GaAs IMPATT oscillators with respect to noise properties. The results indicate that the GaAs FET oscillator will soon be joining the family of microwave solid-state oscillators as a promising new member.     

Triple-push oscillator approach: theory and experiments

This paper presents the theory and experiments of the triple-push oscillator approach. This oscillator architecture is combined with three identical oscillator subcircuits. An analytical mode analysis is used to describe the behavior of all modes. As will be shown, odd-mode currents in each oscillator subcircuit have a 120° phase shift to one another and thus produce in-phase combining for the third harmonic. The time domain analysis was performed to simulate a triple-push oscillator, showing that the phenomenon of 120° phase shift exists among each oscillator subcircuit. To prove this concept, a 4.9-GHz hybrid bipolar junction transistor (BJT) circuit and a 28.4-GHz heterojunction bipolar transistor (BJT) MMIC chip were demonstrated. The measured results showed that the 4.9-GHz BJT triple-push oscillator delivered an output power of 1.0 dBm at 4.9 GHz with 12.0-dB fundamental rejection, and the 28.4-GHz HBT MMIC chip exhibited a measured center frequency at 28.4 GHz with an output power of -15.4 dBm, while the output powers of the fundamental and the second harmonic signals were suppressed to -21 and -34 dBm     

改善宽带行波管性能的谐波注入技术

对谐波注入技术进行了系统地分析,给出了计算机模拟结果和实验数据,并对所得结果进行了比较,得到了谐波注入技术能够有效提高行波管基波输出功率和展宽行波管带宽的结论。     

UHF微带裂环介质谐振器FET振荡器分析

本文提出了微带裂环介质谐振器FET振荡器电路,分析了FET电路和微带裂环谐振器的特性,最后给出设计这种振荡器的频率温度稳定性考虑与优化方法.     

LSA circuit admittance at fundamental and second harmonic frequencies

Measurements have been made of the circuit admittance at the fundamental and second harmonic frequencies for an LSA relaxation oscillator when tuned to give maximum output at either the fundamental or the second harmonic frequency.