Temperature-Stabilized 1.7-GHz Broad-Band Lumped-Element Circulator

A new construction technique for broad-banding and temperature stabilization of a lumped-element circulator is presented to obtain a compact circulator for practical usage. By using a new integrated wide-banding network consisting of three series resonant circuits on the back of the junction substrate, 1.7-GHz double-tuned and triple-tuned broad-band circulators have been successfully developed. Fundamental junction parameters, such as an in-phase eigeninductance, parasitic capacitance, and nonreciprocal filling factor, have been investigated experimentally. A design theory for temperature compensation of a lumped-element circulator is also presented, and temperature compensation with bias magnetic field of postitive temperature coefficient has been applied to the 1.7-GHz broad-band circulators. As a result, 20-dB isolation bandwidths of more than 600 MHz (double-tuned type) and 950 MHz (triple-tuned type) have been obtained throughout the temperature range of -10 ~ +60/spl deg/C.     

Design of a 1.7-GHz low-power delay-fault-testable 32-b ALU in 180-nm CMOS technology

In this paper, we present the design of a 32-b arithmetic and log unit (ALU) that allows low-power operation while supporting a design-for-test (DFT) scheme for delay-fault testability. The low-power techniques allow for 18% reduction in ALU total energy for 180-nm bulk CMOS technology with minimal performance degradation. In addition, there is a 22% reduction in standby mode leakage power and 23% lower peak current demand. In the test mode, we employ a built-in DFT scheme that can detect delay faults while reducing the test-mode automatic test equipment clock frequency.     

Design of high-power, high-efficiency 60-GHz MMICs using animproved nonlinear PHEMT model

This work describes the design and nonlinear modeling of two V-band monolithic microwave integrated circuit (MMIC) power amplifiers using a nonlinear high electron mobility transistor (HEMT) model developed specifically for very short gate length pseudomorphic HEMTs (PHEMTs). Both circuits advance the state-of-the-art of V-band power MMIC performance. The first, a single-ended design, produced 293 mW of output power with a record 26% power-added efficiency (PAE) and 9.9 dB of power gain at 62.5 GHz when measured on-wafer. The second MMIC, a balanced design with on-chip input and output Lange couplers for power combining, generated a record 564 mW of output power (27.5 dBm) with 21% PAE and 9.8 dB power gain. The MMIC's are passivated, thinned to 2 mils, and down-biased to 4.5 V for high reliability space applications. These excellent first-pass MMIC results are attributed to the use of an optimized 0.1-/μm PHEMT cell structure and a design based on millimeter-wave on-wafer device characterization, together with a new and very accurate large signal analytical FET model developed for 0.1-/μm PHEMTs     

Ultra-Low-Noise 1.2- to 1.7-GHz Cooled GaAsFET Amplifiers

A 3-stage GaAsFET amplifier operating at 13 K, utilizing source inductance feedback is described. The amplifier has a noise temperature of <10 K, input return loss >15 dB over the 1.2- to 1.7-GHz frequency range.     

Adaptive nulling loop control for 1.7-GHz feedforward linearizationsystems

An adaptive analog control system is introduced for the nulling loop (first loop) of a 1.7-GHz feedforward linearization system. The sensitivity to temperature and frequency variations is experimentally shown for a conventional feedforward system, leading to the need for an adaptive control system. Two error signals based on detected power levels are introduced and used to control the nulling loop vector modulator to ensure cancellation of the main signal. Finally, the experimental performance of this system is presented     

A 540-640-GHz high-efficiency four-anode frequency tripler

We report on the design and performance of a broad-band, high-power 540-640-GHz fix-tuned balanced frequency tripler chip that utilizes four planar Schottky anodes. The suspended strip-line circuit is fabricated with a 12-/spl mu/m-thick support frame and is mounted in a split waveguide block. The chip is supported by thick beam leads that are also used to provide precise RF grounding. At room temperature, the tripler delivers 0.9-1.8 mW across the band with an estimated efficiency of 4.5%-9%. When cooled to 120 K, the tripler provides 2.0-4.2 mW across the band with an estimated efficiency of 8%-12%.     

On the development of a high-efficiency 750-GHz frequency triplerfor THz heterodyne systems

The development of a 750-GHz Schottky varactor diode frequency tripler having a measured output power and efficiency of more than 120 μW and 0.8% at a frequency of 803 GHz is described. The output powers and efficiencies are the highest reported for this frequency. The 750-GHz tripler mount is analyzed and optimized using a scaled model of the mount. Measurements of the embedding impedance seen by the device, using the model, are compared with theoretical values     

A high-efficiency quasi-optical mode converter for a 140-GHz 1-MW CW gyrotron

A highly efficient quasi-optical mode converter system with several novel features has been designed and tested at Forschungszentrum Karlsruhe (FZK). The converter consists of a dimpled-wall waveguide launcher, one quasi-elliptical mirror and two toroidal mirrors. The coupled-mode theory has been used to analyze the operation of the prebunching waveguide launcher; the radiated fields from the cut of the launcher have been calculated by the scalar diffraction integral. Simulation results show that the advanced dimpled-wall launcher generates a well-focused Gaussian radiation pattern with low diffraction losses. In this case, toroidal mirrors are sufficient to obtain a desired output beam pattern. An efficiency of more than 98% has been achieved to convert the rotating TE/sub 28,8/ cavity mode at 140 GHz into a fundamental Gaussian beam. Experimental measurements show close agreement with theoretical predictions.     

一款高效微波聚焦热疗系统的设计

为了有效提高微波热疗系统的能量利用效率,改善肿瘤治疗效果,设计一款高效率微波聚焦热疗系统。该系统的辐射器采用36单元环形阵列天线,人体等效模型采用三层匹配介质加载,并利用天线聚焦算法实现辐射器能量在人体模型深部的靶向聚焦。仿真和实验结果表明,相比于单层人体匹配介质层加载的系统,该系统能量利用效率达到之前的3倍,既实现了体外微波能量的有效穿透,又保证了穿透到人体内部的电磁能量靶向聚焦,克服了一般微波热疗系统中由于散射和折射引起的电磁能量损耗问题。     

Design and Performance of a 45-GHz HEMT Mixer

A 45-GHz single-ended HEMT mixer has been developed with unity gain and 7-8-dB SSB noise figure over a 2-GHz bandwidth, including an IF amplifier, and 2-dBm output intermodulation intercept. This paper describes its design, structure, and performance. High performance has been achieved by careful attention to the design of the input and output embedding networks. This is the first reported HEMT mixer and the first active mixer above 30 GHz.     

Low-leakage, high-efficiency, reliable VPE InGaAs 1.0-1.7 µm photodiodes

High-quality InGaAs vapor-grown photodetectors for the 1.0-1.7 µm spectral region with a 100 µm diameter active area, ∼10-30 nA leakage current, 65-75 V breakdown voltage, 60-80% quantum efficiency, < 0.5 ns pulse rise time, < 1 pW/Hz^1/2noise equivalent power and stable leakage current at 60°C for over 4000 hours are described.     

Design and analysis of DC-to-14-GHz and 22-GHz CMOS cascode

The designs of two fully integrated CMOS cascode distributed amplifiers (DAs) with 14-GHz and 22-GHz bandwidth are presented. Cascode gain cells and m-derived matching sections are used to enhance the gain and bandwidth performance. These amplifiers demonstrated the highest frequency and widest bandwidth of operation for amplifiers using regular CMOS processes to date. This paper also describes the analysis to design the cascode CMOS DA, together with the small-signal models, EM simulation of the spiral inductors on the silicon substrate, and the analysis of the cascode device. Good agreement between measured and simulated results was achieved for both of the DA designs.     

一种轻量化高效率P频段数字阵列模块设计

为了满足未来大型相控阵天基雷达对低剖面、轻量化有源天线阵面的需求,设计了一种P频段14通道数字阵列模块(Digital Array Module,DAM).通过精简的系统架构设计、高密度集成的电路设计和紧凑的结构设计一系列技术方法,克服了DAM小型化和轻量化的设计难点,同时又获得了高效率和其他优良的电性能.最终研制得到...     

高效率F类功率放大器设计

F类功率放大器是一种高效率的放大器,其理论效率可以达到100%,在无线通信领域中有着广泛的应用和广阔的发展前景。简要阐述了F类放大器的基本理论,并对其效率进行了分析。设计出了带有输入输出谐波控制的高效率F类功率放大器,仿真结果表明在工作频率1 GHz时,输出功率为38 dBm,功率附加效率为74%;输出功率和功率附加效率都优于同条件下的B类功率放大器。     

Design and implementation of a high-efficiency concurrent dual-band power amplifier

This paper studies the behaviors of power amplifier (PA) driven by a single-carrier continuous wave (CW) signal and a two-carrier CW signal both in theory and simulation, and explains why the traditional dual-band PA failed to perform satisfactory results when a two-carrier CW signal is applied to, called concurrently. Besides that, an evaluation standard of concurrent dual-band PA was presented to value its performance. Solution was given with design and fabrication of a concurrent 1.85 GHz/2.65 GHz class F PA, employing a 10W GaN HEMT device from Cree, CGH40010, whose measurement shows the saturated output power is 40.6 dBm and 40.8dBm with drain efficiencies (DE) of 77.4% and 75.3% at 1.85 GHz and 2.65 GHz, respectively. On the other hand, we see that the peak DE achieves 59.7% with an output power of 39.9 dBm in concurrent mode, which follows up with the standard.     

Design and analysis of a coaxial coupler for a 35-GHz gyroklystronamplifier

A single rectangular TE₁₀ feed four-slot coaxial coupler is designed and built for excitation of a TE₀₁₁ cylindrical cavity mode for use in high-power millimeter-wavelength gyroklystron amplifiers. A high degree of mode purity is obtained and matching of the cavity to the input line is studied. A model based on the mode-matching technique and dipole radiators has been formulated to predict operation of this coupler. The resulting numerical code is capable of finding resonant frequency and cavity bandwidth in a small fraction of the time taken by more general finite-difference/finite-element design tools. The model can be extended to self-consistently include an electron beam, and the model is compared to a coupler design based on Hewlett-Packard's High-Frequency Structure Simulator code. The coupler has been successfully used in a high-power gyroklystron-amplifier experiment     

Design and characterization of a 250-350-GHz fixed-tunedsuperconductor-insulator-superconductor receiver

A fixed-tuned superconductor-insulator-superconductor (SIS) receiver has been designed to operate in the 250-350-GHz frequency band. This receiver has a double-side-band noise temperature of between 35 and 45 K, or about 3hν/k_B, over its entire operating band. Extensive characterization of the receiver has been carried out using techniques developed for submillimeter waves. The input noise, side-band ratio, 1 dB compression point, optimum LO drive level, and vector near-field beam profile have all been measured experimentally. The measurement techniques and results are presented and discussed     

一种5 GHz WLAN CMOS正交调制器和上变频器的设计

介绍了应用于WLAN IEEE 802.11a的正交调制器和上变频器的设计,给出了详尽的优化方法。正交调制器在传统Gilbert单元的基础上,采用负反馈跨导放大器来提高线性度;上变频器采用RLC谐振网络作Gilbert单元负载来提高增益,增加电压输出摆幅。电路采用TSMC 0.18μm 6层金属混合信号/射频CMOS工艺实现。在1.8 V电源电压下,静态电流为30 mA。测试结果表明,在谐振频率点的1 dB压缩点P1-dB为-8 dBm,电压增益为-2.4 dB,本振泄漏小于-50 dBm。     

一种2GHz512/256静态分频器电路的设计

介绍了一种高速５１２／２５６分频器电路的设计,其基本结构采用静态主从Ｄ触发器。电路采用先进的单层多晶硅发射极双极工艺制造,使用３μｍ设计规则,电路的最高工作频率达到２ＧＨｚ。