X波段GaN基小相位移相器设计

Design of X-Band GaN-Based Small Phase Shifters

基于0.25μm GaN HEMT工艺,设计并制作了X波段11.25°和22.5°的小相位移相器单片微波集成电路（MMIC）,两个移相器单元均采用低通开关滤波型拓扑结构。最终芯片面积分别为0.9 mm×1.05 mm和0.95 mm×1.05 mm。芯片测试结果表明,两个小相位移相器性能良好,且测试结果与仿真结果吻合。在8~12 GHz频带内,11.25°和22.5°移相器电路的相移精度小于2.8°,输入回波损耗分别优于-15和-12 dB,插入损耗值分别小于1和1.5 dB,幅度波动分别小于0.8和1.3 dB。两个移相器电路的1 dB压缩点输入功率均大于36 dBm,其功率容限优于GaAs HEMT设计的移相器。结果表明,所设计的移相器具有优异的相移精度以及良好的功率性能,可广泛应用于高精度和大功率的雷达系统中。

Based on the 0. 25 μm GaN HEMT process,11. 25° and 22. 5° X-band small phase shifter monolithic microwave integrated circuits（ MMICs） were designed and fabricated,with both of the phase shifter units in low-pass switched filter topology structure. The final chip areas are 0. 9 mm ×1. 05 mm and 0. 95 mm×1. 05 mm,respectively. The chip test results show that two small phase shifters are in good performance and in agreement between the simulation and test results. Within 8-12 GHz frequency band,the 11. 25° and 22. 5° small phase shifter circuits achieve the phase shifting accuracies of less than 2. 8°,the input return loss of better than-15 and-12 dB,the insertion loss of less than 1 and1. 5 dB and the amplitude fluctuation of less than 0. 8 and 1. 3 dB,respectively. The input powers at the 1 dB compression point of the two phase shifter circuits are larger than 36 dBm,with better power margin than the shifter designed with Ga As HEMT. The results show that the designed phase shifters can be widely used in the high-precision high-power radar system due to their excellent phase shifting accuracy and good power performance.