Design of a Ultra-Wide-Band Duplexer without Magnet and Ferrite

In this paper, we investigate the design, study, and implementation of an ultra-wideband duplexer. The device we developed is based on microstrip technology and does not require ferrite or other magnetic materials. Its structure includes a wideband Wilkinson power divider and a low-gain radio-frequency amplifier that uses an inexpensive and readily available BFR91A bipolar transistor , making it easy to fabricate and integrate into low-power systems such as radio-frequency chips. The effectiveness of the proposed design has been evaluated through experimental measurements using a vector network analyzer.