New inkjet-printed wideband 3-dB branch-line coupler

Summary form only given, as follows. A new inkjet-printed wideband 3-dB branch-line coupler is introduced and compared with an identical circuit produced by conventional etching. The circuit has been realized with a silver ink on a Chukoh substrate with relative permittivity of 2.6. The circuit has been simulated with HFSS and printed by an OmniJet inkjet printer. Measurement shows S21 better than 3.6dB, S31 better than 6.6 dB, input return loss better than 20 dB, and isolation better than 18dB over 43% bandwidth.