A Circular Radiating Patch Filtering UWB Antenna With Improved Band-edge Selectivity

In this study, a circular radiating patch filtering UWB antenna with good selectivity is proposed. By designing a compact bandpass filter to replace the 50 ohm feeding line of the circular monopole antenna, the selectivity of the upper and lower sidebands of the antenna are improved, thereby enabling the antenna to have a filtering function. The proposed design provides a 116.8% passband bandwidth, ranging from 3 to 11 GHz. In order to better evaluate the sideband selection characteristics of the antenna reflection coefficient, the shape factor is defined. Both reflection coefficient and gain of the proposed design show good filtering characteristics. The size of the filtering antenna is 32 mm × 25 mm, which is still smaller than most UWB antennas without filtering function.