5-bit RF MEMS Switch Time Delay Line Shifter

A 5-bit radio frequency (RF) micro-electromechanical system (MEMS) time delay line shifter operating over ultra-wide frequency ranges from 6 to 11 GHz is designed and fabricated. The time delay line shifter provides five bits delay: λ、2λ、4λ、8λ、16λ. The shifter circuit is fabricated by using microwave multilayer printed circuit board technology, and the shifter circuit is in four layers. The size of the shifter is 45mm×20mm . The shifter is composed of twenty series cantilever switches actuated by electrostatic voltage of 60-75V. Measurements show that the return losses are less than -10dB from 6 to 11GHz, and the insertion losses are between -8dB and -10dB for most states. In the center frequency, the biggest delay time bit is 1680Ps, the total delay time is 3255ps.