Ku-Band Six-Bit RF MEMS Time Delay Network

A six-bit time delay circuit operating from DC to 18 GHz is reported. Capacitively loaded transmission lines are used to reduce the physical length of the delay elements and shrink the die size. Additionally, selection of the reference line lengths to avoid resonances allows the replacement of series-shunt switching elements with only series elements. With through-wafer transitions and a packaging seal ring, the 7 mm x 10 mm circuit demonstrates <2.8 dB of loss and 60 ps of delay with good delay flatness and accuracy through 18 GHz.