A reconfigurable defected microstrip structure for applications in phase shifter

A reconfigurable defected microstrip structure (RDMS) is proposed for phase shift applications. The RDMS unit is made by etching a rectangle slot in a segment of microstrip line and then loading the slot with PIN diodes and capacitors. A phase shift is achieved by switching the diodes between the “on” and “off” states. By cascading such RDMS units, a stepwise phase shifter is realized. The measured results show that the phase shifter is able to achieve phase shifts of 0°, 44°, 95°, and 143° with a maximum insertion loss of 2.3 dB at 5.2 GHz. The RDMS based phase shifter has a simple fabrication process and is easy to be integrated in microstrip systems, and thus provides a low cost solution to phase control in microstrip antenna arrays.