Supported bars novel cantilever beam design for RF MEMS series switches

The paper presents a novel cantilever beam RF MEMS metal to metal contact series switch. The proposed cantilever design is supported with three supporting bars at the rear end of the beam. These bars not only make the smooth mechanical movement of the beam but also result in a low spring constant. The beam has a spring constant of 3.37 N/m. The switch has actuation voltage as low as 19 V. To control the residual stress a dimple has been added at the front tip of the beam. Issues regarding the residual stress during fabrication have been discussed. In the novel beam design, we have introduced geometrical variations which have lead to good RF performance. The measured insertion loss is 1.15 dB with isolation better than 23 dB and return loss better than 19 dB up to 40 GHz. Proposed switch can easily be integrated in large multiport structures.