A 1.6-2.3-GHz RF MEMS Reconfigurable Quadrature Coupler and Its Application to a 360° Reflective-Type Phase Shifter

This paper presents the design, fabrication, and measurement of a reconfigurable quadrature hybrid coupler and a tunable low-loss reflective-type phase shifter built using the Cavendish Kinetics RF microelectromechanical systems switched capacitor devices. The quadrature coupler tunes from 1.5 to 2.2 GHz with 20-50-MHz steps, and > 20-dB reflection and isolation. The phase shifter covers 360 degrees at 2.0 GHz with an insertion loss of 2.0 +/- 0.5 dB at different phase states. The linearity measurements show that these devices can handle up to 5 W of input power at 1.8-2.2 GHz with an input third-order intercept point (IIP3) > 44 dBm over all phase states. The measured second and third harmonic components are < -90 dBc at 30 dBm of RF input power. The application areas are in-phase shifters for micro and pico base-stations in the 1.7-2.3-GHz range.