一种D波段小型化定向耦合器芯片设计

Design of on-chip D band miniaturized directional coupler

基于GaAs 0.1 μm pHEMT工艺,设计了一款工作在0.1~0.14 THz的小型化定向耦合器芯片。采用加载开路枝节线的方式提高传输线的等效电长度,进而实现电路结构的小型化;利用曲折线的方式构成开路枝节线,使得耦合器的物理尺寸进一步缩小。采用电磁仿真软件仿真表明,所设计的小型化定向耦合芯片中心工作频率为0.12 THz,相对带宽大于30%,带内的回波损耗高于20 dB,带内插入损耗小于1 dB,耦合度为(10±0.5) dB,带内隔离度大于20 dB,直通端口与耦合端口相位差为90°±3.5°,其尺寸为0.21 mm×0.19 mm(不计Pad尺寸)。

Based on the 0.1 μm GaAs HEMT process, a miniature directional coupler chip operating in 0.1-0.14 THz is designed. The equivalent electric length of the transmission line is increased by loading the open branch to miniaturize circuit structure. The physical size of the coupler is further reduced by using the zigzag line,which is realized by the open branch and node line. Simulation results show that the designed miniaturized directional coupling chip has a center operating frequency of 0.13 THz, a relative bandwidth of more than 30%, an in-band echo loss of more than 20 dB, an in-band insertion loss of less than 1 dB, a coupling degree of (10±0.5) dB, a phase difference of (90°±3.5°), and a size of 0.21 mm×0.19 mm(without pad).