X-band RF MEMS phase shifters for phased array applications

In this letter, development of a low-loss radio frequency (RF) microelectro mechanical (MEMS) 4-bit X-band monolithic phase shifter is presented. These microstrip circuits are fabricated on 0.021-in-thick high-resistivity sili con and are based on a reflection topology using 3-dB Lange couplers. The a verage insertion loss of the circuit is 1.4 dB with the return loss >11 dB at 8 GHz. To the best of our knowledge, this is a lowest reported loss for X-band phase shifter and promises to greatly reduce the cost of designing a nd building phase arrays.