A wideband three‐way out‐of‐phase microstrip power divider based on the wideband phase inverter is presented. The measured return loss is <−10 dB and the isolations are better than −19 dB from 2.5 to 5.37 GHz. The insertion losses are <0.6 dB, and the output amplitude imbalances are <0.9 dB. The phase differences (ang(S41)–ang(S42)) are within 180 ± 6°. The operation bandwidth of the proposed design achieves about 73.4% efficiency.

A novel reconfigurable phase inverter architecture allowing frequency‐switchable is proposed. Interdigital striplines, metallic via holes, and the defected ground structure are used to obtain 180° phase inverter. The switchable frequency is controlled by the length of the slot‐line on the defected ground which can be changed by PIN‐diodes and a single control voltage. For verification, the simulated and measured results of switchable frequency at 900 MHz and 1.6 GHz phase inverter implemented on microstrip are shown.