带有小型化Balun的C波段单片GaAs pHEMT单平衡电阻性混频器

C-Band Monolithic GaAs pHEMT Resistive Single-Balanced Mixer with Miniaturized Balun

本文介绍了一种带有小型化无源Balun的C波段单片GaAs pHEMT单平衡电阻性混频器。Balun采用集总一分布式结构，使其长度与常用2／4耦合线Balun相比缩小了11倍，大大降低了将无源Balun应用于C波段单片集成电路中所需的芯片尺寸。混频器采用单平衡电阻性结构，在零功耗的情况下实现了良好的线性和口间隔离性能。测试结果显示，在固定中频160MHz，本振输入功率0dBm条件下，在3．5～5GI-IzRF频带内，最小变频损耗为8．3dB，1dB压缩点功率为8．0dBm，LO至Ⅲ之问的隔离度为38dB。

A C-band GaAs pHEMT single-balanced resistive mixer with miniaturized balun is presented. By using lumped-distributed structure, the coupled-line length was reduced by a factor of 11 compared with the conventional 2/4 coupled-line balun. This balun was then used in a resistive mixer to transform the input single-ended signal into differential. The mixer achieved good linearity and port isolation performance with zero power consumption. Test results showed that, with a fixed IF of 160 MHz and 0dBm LO power,the minimum conversion loss is 8.3dB in 3.5 - 5GHz RF frequency range. The measured ldB compression point is 8dBm and the LO-to-IF isolation is better than 38dB.