开关线型四位数字MEMS移相器

介绍了一种基于射频微机械串联开关设计的开关线型四位数字微机电系统(M icro-e lectrom echan ica lSystem s以下简称M EM S)移相器。该移相器集成了16个RF M EM S开关,使用了13组四分之一波长传输线和M IM接地耦合电容,有效地使开关的驱动信号和微波信号隔离,串联容性开关设计有效地降低了开关的启动电压。使用低温表面微机械工艺在360μm厚的高阻硅衬底上制作移相器,芯片尺寸4.8 mm×7.8 mm。移相器样品在片测试结果表明,频点10.1 GH z,22.5°相移位的相移误差为±0.4,°插损2.8 dB;45°位的相移误差为±1.1,°插损2.0 dB;在X波段,对16个相移态的测试结果表明,移相器的插入损耗小于4.0 dB,驻波比小于2.4,开关驱动电压为17~20 V。

A 4-bit Switched-line Digital MEMS Phase Shifter

A 4-bit digital MEMS phase shifter is presented,which is based on switched-line design and composed of 16 series RF MEMS switches and 13 groups of the quarter-wavelength of microstrip with MIM ground coupling capacitors.With this configuration,the DC driven voltage can be separated from the RF signal effectively and low pull-down voltage of the switches can be achieved.The phase shifter is fabricated on a 360 μm-thick silicon substrate by low temperature metal-dielectric surface micromachining process,and the chip size is 4.8 mm×7.8 mm.Measurements show that the phase error of ±0.4° corresponds to the phase shift of 22.5° at 10.1 GHz where the insertion loss is 2.8 dB and the phase error of(±1.1°) corresponds to the phase shift of 45° where the insertion loss is 2.0 dB.The insertion loss is less than 4 dB and the VSWR is less than 2.4 for all 16 phase states at X-band and the pull-down voltage is 17～20V.