High-linearity reconfigurable microstrip UWB bandpass filters

This paper presents a high linearity reconfigurable ultra-wideband (UWB) filter. The proposed structure is able to achieve high performance with good linearity and no significant loss. A single PIN diode (BAP65-02) is used to switch the filter from a bandpass to a bandstop response at the same UWB spectrum. An optical switch, comprised of a silicon dice activated using near infrared light is also investigated as an alternative to the PIN diode. This reconfigurable UWB filter behaves as a bandpass filter while the switch is in the ON state and acts as a bandstop filter while in the OFF state. A prototype is fabricated and measured results are compared to simulations. A good agreement has been achieved between simulated and measured results with both the PIN diode as well as the optical switch.