A Differential UWB Quasi-Yagi Antenna with a Notched Band at 5.8 GHz

Abstract

A compact differential ultra-wide band (UWB) planar quasi-Yagi antenna is presented in this paper. The proposed antenna can not only realize a wide differential-mode (DM) impedance bandwidth covering from 3.8 to 9.5 GHz, but achieve a high and wideband common-mode (CM) suppression by employing the balanced stepped-impedance microstrip-slotline transition structure. Besides, the DM passband is independent from the CM response, simplifying the design procedure significantly. In addition, a sharp DM notched band at 5.8 GHz is generated by adding one pair of quarter-wavelength short-circuited stubs adjacent to the microstrip line symmetrically. In order to illustrate the effectiveness of the design, one prototype of the antenna is designed, fabricated, and measured. A good agreement between the simulated and measured results is observed.