Research on Key Components for Microwave and Millimeter-Wave Wideband Systems
Date Issued
2013
Date
2013
Author(s)
Kao, Jui-Chih
Abstract
In this thesis, three wideband circuits are presented, including a modified Wilkinson power divider and its applications, a broadband distributed amplifier, and a wide IF bandwidth triple cascode down-conversion mixer.
The modified Wilkinson power divider uses a frequency dependent isolation network to extend its isolation bandwidth. Using the proposed design methods, the specific Wilkinson-based power divider (equal, unequal, multi-ways, and specific phase difference output) can achieve very wide isolation bandwidth without sacrificing the isolation at the center frequency. The operation fractional bandwidths for the modified Wilkinson power dividers, which are determined by the intersection of 10-dB return loss, 1-dB insertion loss, and 20-dB isolation, are better than 105% in the experiments. The realized examples demonstrate the concept for the isolation bandwidth extension very well.
The broadband distributed amplifieruse a novel combination topology for higher gain, higher output power, and lower noise figure. This circuit combines the conventional distributed amplifiers and cascade-single-stage distributed amplifiers, and takes the advantages of them. Also, the interstage termination removed technique is used in this design for higher gain. A 0.18-μm CMOS distributed amplifier is realized to demonstrate the design concepts in chapter 3. The amplifier costs 0.83-mm2 circuit area and 238-mW power consumption, and it obtains 24-dB gain, 523 gain-bandwidth product, 5-dBm output power, and 7.5-dB noise figure from 2 GHz to 35 GHz. The measured results agree with the simulation very well.
Finally, a W-band triple cascode down-conversion mixer with wide IF bandwidth and high LO-to-RF isolationis fabricated in 0.15-μm pHEMT. In this circuit, the modified resistive mixing core and the Butterworth type low pass filter are designed for wide IF bandwidth. The triple cascode topology improves the LO-to-RF isolation with very small extra circuit area. To estimate the circuit performance more precisely in W band, the Angelov transistor models are made and used in the design. The circuit occupies 1-mm2 chip area and 24-mW power consumption. The measured results show that this mixer can provide 13-dB conversion gain, 25-GHz IF bandwidth, and 38-dB port-to-port isolation when the LO frequency is 86 GHz, and 14-dB conversion gain, 25-GHz IF bandwidth, and 29-dB port-to-port isolation when the LO frequency is 96 GHz.
Subjects
魏金森分功器
分佈式放大器
W頻段
假型高速電子遷移率電晶體
Type
thesis
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