半导体开关与RFMEMS开关性能分析与比较

Performance analysis and comparison of semiconductor and RF MEMS switches

为找出影响微波开关性能的参数及其开关的发展方向,从物理机理上分析和比较了半导体开关和RFMEMS(射频微电机械)开关的性能。提出了微波串联开关的理想模型,定义了开关的品质因数,应用器件物理理论和电容公式推出了半导体开关和MEMS开关的品质因数表达式,分析出影响开关性能的参数,提出改善的方法。通过相关权威测试的品质因数得出:RFMEMS开关比半导体开关具有更优的性能,与理论分析相一致。通过开关的性能比较,明确RFMEMS开关可广泛地应用到射频微波电路中,有好发展前景。

In order to find the parameters affecting the performance of microwave switches and the developing direction of switches, the performance of semiconductor and RF MEMES switches is analyzed and compared in terms of physical working mechanism of device. An ideal model of microwave series switches is presented, FOM （figure of merit） of switches is defined. The mathematical expressions of FOM for semiconductor and RF MEMS switches are derived from theories of device physics and formula of a capacitor, the parameters affecting the performance of switches can be found, and the methods improving the performance of switches are proposed. According to test data of some authoritative literatures, the conclusion can be drawn that RF MEMS switches have better performance than senficonductor switches, which is in consistent with theoretical analysis. RF MEMS switches are of a promising direction and are extensively applied in rnicrowave/RF circuits according to comparison results of the performance of RF MEMS switches.