UMTS-WiFi Switchable Bandpass Filter
In this paper a reconfigurable band-pass filter able to switch between WiFi and UMTS transmit band standards is presented. The filter is designed in such a way that center frequency and bandwidth specifications are precisely met by defining a switchable filter topology that includes two folded resonator extensions switched by two PIN diodes. Design specifications require two center frequency states, one at 2.440 GHz with an 80 MHz bandwidth and a second center frequency state at 1.955 GHz with a 140 MHz bandwidth for the WiFi and UMTS transmit bands, respectively. Filter simulations were performed to match the required filter specifications.