Constant-k Filter Design of Reconfigurable Filtering UWB Antenna

The equivalent circuit analysis of low pass and band pass filter integrated into the feedline of reconfigurable filtering antenna working in Ultra-wideband (UWB) is presented in this article. The reconfigurable filtering antenna working in UWB mode, WLAN/ IoT mode, and DSRC/WLAN mode is taken, and circuit analysis is done using constant k-filtering concepts. The low pass filter is adopted to work from 2.1 GHz to 3.9 GHz for WLAN/IoT mode, and the bandpass filter is employed to operate in a 5-6.5 GHz region for DSRC/WLAN mode. The filters are activated by suitably controlling the switches connecting the filters with the feedline. The reconfigurable filtering antenna works in UWB mode if the switches connecting the filters are in the off state. The simulated scattering parameter characteristics of the low pass and band pass filters of the reconfigurable filtering antenna in CST Microwave Studio Suite and Advanced Design Systems (ADS) are in good agreement.