Wideband bandpass‐to‐all‐stop reconfigurable filtering power divider with bandwidth control and all‐passband isolation

A novel wideband bandpass‐to‐all‐stop reconfigurable filtering power divider is proposed in this study, which allows for four‐order bandpass‐to‐all‐stop reconfigurable operating function and equal power division. Its circuit configuration includes the cascaded coupled‐line sections with tight coupling to extend the impedance transforming. Furthermore, with the introduction of the half‐wavelength open‐circuit stubs, which controls the bandwidth, extra transmission poles located at the cut‐off frequency are generated, thus resulting in high frequency selectivity. Moreover, by using a single resistor between input coupled‐lines, the high all‐passband isolation can be achieved. The grounding are then loaded to the output coupled‐lines to enable bandpass‐to‐all‐stop operating functionality. For demonstration, a prototype operating at 2 GHz is designed, simulated, and measured with a 15 dB bandwidth of 51%, 19 dB stopband rejection up to 5 GHz, and 14.5 dB all‐passband isolation, which shows a good agreement between the simulated and measured results.