共查询到20条相似文献,搜索用时 15 毫秒
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A Low-Loss Ku-Band Monolithic Analog Phase Shifter 总被引:1,自引:0,他引:1
《Microwave Theory and Techniques》1987,35(3):315-320
A GaAs monolithic Ku-band analog phase shifter integrating 90° branch line coupler with planar varactor diodes has been fabricated for the first time. A phase shift of 109° +- 3° with an insertion loss of 1.8+-0.3 dB was measured from 16 to 18 GHz. A 360° phase shifter with 4.2+-0.9 dB insertion loss was realized in the same frequency range by connecting three phase-shifter chips in series. To our knowledge, this is the lowest insertion loss obtained by a 360° Ku-band phase shifter using monolithic circuits. In addition, hyperabrupt varactors using nonuniform doping profiles increased the phase shift by more than 30° and produced a more linear dependence of phase shift on control voltage. 相似文献
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Yuyu Chang John Choma Jr. Jack Wills 《Analog Integrated Circuits and Signal Processing》2001,28(1):43-52
A CMOS inductorless image-reject filter based on active RLC circuitry is discussed and designed with the emphasis on low-noise, low-power, and gigahertz-range circuits. Two
-enhancement techniques are utilized to circumvent the low
characteristics inherent in the simple feedback circuit. The frequency tuning is almost independent of
tuning, facilitating the design of the automatic tuning circuitry. The stability and the tuning scheme of the filter are also discussed. Simulations using 0.6 m CMOS technology demonstrate the feasibility of the tunable image-reject filter for GSM wireless applications. Simulation results show 4.75 dB voltage gain, 9.5 dB noise figure, and –20 dBm IIP3 at a passband centered at 947 MHz. The image signal suppression is 60 dB at 1089 MHz and the power consumption is 27 mW. 相似文献
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《Microwave Theory and Techniques》2008,56(8):1945-1953
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A Varactor-Tunable High Impedance Surface With a Resistive-Lumped-Element Biasing Grid 总被引:1,自引:0,他引:1
A high impedance surface consisting of metallic square patches electrically connected through vias to the ground plane beneath them is made tunable. Tunability is achieved by connecting adjacent patches with varactor diodes thus altering the capacitance between the patches and hence the surface's resonance frequency. The varactor diodes are biased with the aid of a resistive grid. The grid is made resistive using surface mount resistors. Using an approximate equivalent circuit the effect of the varactor diode resistance is investigated for normal plane wave incidence. It is shown that at resonance, a small varactor resistance may lead to a significant absorption. The potential use of a waveguide simulator to characterize approximately the performance of the proposed metamaterial structure is investigated. 相似文献
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《Microwave Theory and Techniques》1974,22(10):891-894
A waveguide filter which separates the 4-GHz band the combined 4-, 6-, and 11-GHz common-carrier bands with a loss of only 0.05 dB is described. The input is limited to a single polarization, but dual polarizations can be accommodated by using two such filters in combination with a polarization coupler. The filter also has low insertion losses at 6 and 11 GHz: 0.1 dB and 0.06 dB, respectively, a good return loss, 32 dB, and a short length, 2 1/2 ft. Additionally, it has high power-handling capability, good isolation properties, and good mode purity. 相似文献
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《Solid-State Circuits, IEEE Journal of》2009,44(3):699-707
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本文介绍单片晶体滤波器在移动通讯设备中的用途及特点,给出了其设计的基本方法。并给出了一个实例的指标及应用情况。 相似文献
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Galbraith C.J. Hancock T.M. Rebeiz G.M. 《Microwave and Wireless Components Letters, IEEE》2007,17(11):772-774
In this letter, we present a state-of-the-art, planar double-tuned transformer using high-, micromachined spiral inductors and integrated capacitors. This circuit provides a 4:1 impedance transformation over a 30% bandwidth centered at 4.06 GHz, with a minimum insertion loss of 1.50 dB. The fabricated circuit occupies a total area of 440 times 500 mum2and finds application in power amplifier and other matching applications. An accurate lumped-element circuit model and design tradeoffs are presented. We believe this is the first implementation of a planar microwave double-tuned transformer. 相似文献
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《Microwave and Wireless Components Letters, IEEE》2009,19(6):377-379
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一种单片微机控制的锁相环频率合成器 总被引:2,自引:0,他引:2
本文报导我们研制的一种单片微机控制的锁相环频率合成器。它以大规模集成芯片MC145146为中心,配以参考振荡器、环路滤波器、直流放大器、压控振荡器、双模前置分频器以及单片机频率控制系统。 相似文献
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《Solid-State Circuits, IEEE Journal of》2009,44(7):2026-2035