ABSTRACT
This chapter aims to further improve the phase shifter performance in terms of loss, matching, size and reliability, a new topology is proposed that drastically reduces the number of switch counts in a 5-bit digital phase shifter at 17 GHz frequency. Radio frequency microelectromechanical systems (RF MEMS) digital phase shifters are reported in the literature with up to 6 bits using switched-line, reflect line, low-pass/high-pass and distributed MEMS transmission line topology in different frequency bands. Multicontact, long and complex designs of cantilever switches are sensitive to stress gradient. The residual stress effects the uneven distribution of tip deflection between all identical structures. To observe the phase shifter reliability over a practical environment, a few more tests are adopted. Initially, reliability of the phase shifter is measured on the chip at 17 GHz frequency, and then the same measurement process is repeated on the phase shifter within a module.
