射频分布式MEMS移相器Bragg频率的研究

详细讨论了Bragg频率产生的原因及其分析方法，并依据微波网络理论对不同结构参数MEMS移相器的Bragg频率进行了分析比较.计算结果表明Bragg频率随共平面波导信号线宽度增大、随微桥周期间距增大而降低.对特征阻抗50 Ω、周期间距300 μm、中心信号线宽度分别为50 μm和100 μm的MEMS移相器，Bragg频率相应为38.1 GHz和27.6 GHz；对中心信号线宽度为100 μm的移相器，当周期间距增加为567 μm时，Bragg频率进一步下降到19.6 GHz.对Bragg频率的研究为分布式MEMS移相器优化设计提供了重要依据.

Bragg Frequency Study of RF Distributed MEMS Phase Shifter

The Bragg frequency, which describes the upper limit frequency of distributed phase shifters, is a very important parameter of RF distributed MEMS phase shifters. This paper discusses in detail the underlying cause and analysis method of Bragg frequency. In addition, by using microwave network theory, the Bragg frequencies of MEMS phase shifters with different dimensions have been calculated. The simulated results demonstrate the Bragg frequency is decreased by increase of the dimension and spacing. The studied phase shifters consist of a CPW line (50 Ω) periodically with MEMS bridges at a spacing of 300 μm. When the widths of the center conductor are chosen to be 50 μm and 100μm, the Bragg frequency are 38.1 GHz and 27.6 GHz, respectively. As the width of the center conductor is fixed at 100 μm, the Bragg frequency reduces form 27.6 GHz to 19.6 GHz with the spacing increasing form 300 μm to 567 μm. Researching the Bragg frequency will benefit the design and optimization of the distributed MEMS phase shifters.