基于简单复合左右手结构的宽带90°移相器

Broadband 90°Phase Shifter Based on Simplified Composite Right/Left-handed Structure

利用简单复合左右手结构的非线性相位特性,提出了一种平面、低插入损耗的宽带90°差分移相器的设计方法。该设计方法的原理主要是通过调节简单复合左右手结构的参数和进行相位比较的传统微带线长度,使二者的相位曲线最大程度具有相同的斜率,并且满足90°的相位差。移相器的幅度和相位测试结果表明:在2.9～8.4GHz的频率范围内,反射系数小于-10dB,插入损耗小于0.7dB,相位不平衡度小于±5°,相对带宽达到了97.3%,而满足相同指标的传统微带差分移相器,其相对带宽仅有11%。该结构设计简单,便于加工。

A method to design planar and low insertion loss phase shifter with broadband characteristic of 90° difference is presented by utilizing the nonlinear phase characteristic of the simplified composite right-/ left-handed transmission line. The measured results show that the proposed phase shifter achieves 2.9-8.4 GHz （97.3%） bandwidth with return loss ≤-10 dB, insertion loss 40.7 dB and phase instability ±5°. Whereas, the relative bandwidth of the conventional difference phase shifter is only 11% when it simultaneously satisfying the above indexes. The proposed structure is simple in design and is easy to be fabricated.