一种基于复合左右手传输线结构的模拟移相器

An Analog Phase Shifter Based on Composite Right/Left Hand Structure

基于0.25μm GaAs pHEMT工艺设计了一种工作在Ku波段的可调谐模拟移相器。该移相器采用集总参数型复合左右手传输线(CRLH-TL)拓扑结构实现相移网络,并利用可变电容结构进行相位调谐。为了解决端口失配问题,插入了共源共栅缓冲器来增加隔离度,并中和无源器件带来的损耗。电路采用统一的偏置电压来控制所有变容结构,简化了电路结构。仿真结果表明,该移相器在工作频率内的相移可调谐范围大于90°,在电源电压为1.5 V下,直流功耗为63.3 mW,平均增益大于8.5 dB,幅度波动小于5 dB。

A Ku-band tunable analog phase shifter(PS) was designed in a 0.25 um GaAs pHEMT process. The composite right/left hand transmission line(CRLH-TL) based on discrete elements was employed to realize the phase shift network(PSN) for the proposed phase shifter. The varactor was used in the PSN to achieve the phase tuning. The buffer with cascode amplifier structure was used to increase the isolation of the PSN, and this buffer was also used to improve the mismatch and loss of the PSN. The PS structure was simplified by adding the same bias voltage to the varactor. The post-layout simulation results showed that the tuning range of PS was greater than 90° over the whole operating frequency range. The DC power consumption was 63.3 mW at a 1.5 V DC supply. The average gain was greater than 8.5 dB, and the amplitude fluctuation was less than 5 dB.