Tapered Slot Antenna With Band-Notched Function for Ultrawideband Radios

A novel tapered slot antenna (TSA) with a band-notched function for ultrawideband (UWB) radios is proposed in this letter. By inserting an Archimedean spiral-shaped slot into a microstrip open-circuit circular stub of microstrip-slotline transition, a UWB operation with a notched frequency band can be obtained. Measured data for the optimized case show the bandwidth for the VSWR <; 2 to be 8.8 GHz (from 2.4 to 11.2 GHz) with a notched band frequency from 4.6 to 6.2 GHz. By inserting the resonance slot on the nonradiating part of the antenna, the proposed antenna is capable of avoiding the spatial-dependent bandstop characteristics. Also, the designed antenna has a small size of 50 × 50 mm
²
, which is a size reduction of 40% with respect to previous similar antennas.