RF MEMS switches, switching networks and phase shifters for microwave to millimeter wave applications

Abstract

This work presents design, fabrication and measurements of RF MEMS metal-contact switches, switching network and phase shifters. The complete work is broadly divided into three parts. The first part concentrates on the metal-contact switch functionalities in terms of mechanical behaviour, electrical behaviour, transient analysis, linearity, power handling, temperature, S-parameter and reliability. All these switch performances are critically evaluated for developing high-performance and reliable MEMS switch. Different single-pole-multi-throw (SPnT) switching networks are also designed and tested where n varies from two to sixteen. Next part concentrates on the design and development of narrow-band (500 MHz) MEMS digital phase shifters (2- to 5-bit) driven by an electrostatic actuation. Next and last phase of this work deals with a reconfigurable MEMS digital phase shifter using a push–pull-type beam topology. The utility of this beam design is validated and tested on a simple DMTL configuration where 11 push–pull bridges are used in a periodic placement. Finally, a modified version of the push–pull actuator is used to design a frequency reconfigurable 5-bit phase shifter over a wide band of spectrum of 10–25 GHz. The concept of the frequency reconfiguration is clearly mentioned and validated with exhaustive measurement process. In addition, a low-cost module is developed using gold-coated brass material to observe optimum device performance for end-user applications and two phase shifters are tested over large cycles including power handling, temperature stability and qualification testing such as 3-axis vibration.