A wideband compact broadside coupler-based impedance transformer with 6∶1 bandwidth

A compact broadband impedance transformer using a broadside coupler is presented. The tradeoff between good return loss and design parameters that can be realistically implemented is considered during the design. To implement the coupler and the required high impedance transmission line, a combination of stripline and microstrip is used. The circuit transforms 50 Ω to 100 Ω from 1 GHz to 6 GHz. The measured return loss is larger than 15 dB from 1.1 GHz to 6.4 GHz. In general, the measured results agree well with the simulated results.