A Compact Differential Quasi-Yagi Antenna With Broadband and Uniplanar Characteristics

Abstract

This paper presents a compact differential quasi-Yagi antenna with broadband and uniplanar characteristics. An impedance transformer is designed combining a section of tapered coupled microstrip lines (TCML) and a section of coplanar strips (CPS). The proposed antenna exhibits a −10 dB differential-mode (DM) return loss bandwidth of 54.1% (7.95 to 13.85 GHz) with efficiency of around 94%. The front-to-back ratio is better than 9.1 dB while the cross-polarization is less than −20 dB. Besides, simulated results demonstrate that the maximum common-mode (CM) rejection is 0.6 dB and the gain is from 3.4 dBi to 5.5 dBi within the operating bandwidth.