A Compact Single Layer Filtering Antenna with DGS for 5.1 GHz Application

Abstract

|A compact bandpass (cid:12)ltering antenna operating at 5.1 GHz is introduced. The radiation layer makes up of a U-shaped patch and a trident resonator. The U-shaped patch is both the antenna and the last stage of the (cid:12)lter, which is excited by the insertion coupling part of the trident resonator. To improve the impedance matching and lower stopband suppression, a defective ground structure (DGS) is used. The dimension of the antenna is 0 : 36 (cid:21) 0 (cid:2) 0 : 36 (cid:21) 0 (cid:2) 0 : 01 (cid:21) 0 ( (cid:21) 0 is the wavelength at 5.1 GHz) without a complex external feed structure, which has enough bandwidth, a good frequency skirt selectivity, and a (cid:13)at passband response. The measurement results manifest that the impedance bandwidth is 110 MHz, and the peak gain is 3.88 dBi. In addition, the (cid:12)ltering antenna also has a sharp roll-off rate and a satisfactory level of out-of-band suppression in the stopband.