Design of compact low‐profile planar filtering antenna with enhanced suppression level

Abstract

A compact low‐profile planar filtering antenna with an enhanced suppression level is presented in this paper. The presented antenna has a simple structure, consisting of an E‐shaped driving patch, a shorted parasitic patch, and a defected ground structure (DGS). The E‐shaped driving patch serves as an effective radiator and facilitates the filtering response. The shorted parasitic patch is horizontally arranged and coupled with the driving patch through the radiating edge. And a radiation null and an extra in‐band resonance can be generated, which would simultaneously broaden the impedance bandwidth and improve the suppression level. In addition, a DGS on the metalized ground plane is etched to introduce another radiation null, and the out‐of‐band suppression level would be significantly enhanced. The filtering antenna with a center frequency of 3 GHz was constructed and tested to verify its performance. The measured values, which indicate a bandwidth of 10% (2.85–3.15 GHz) and a peak realized gain of 5.2 dBi, are in agreement with the simulated values. The presented filtering antenna features a low profile of 0.016λ0, a compact antenna size of 0.16λ20, as well as an improved suppression level of more than 22 dB.

A novel filtering patch antenna with high selectivity and wide out‐of‐band suppression

“…Nowadays, filtering antennas have been studied intensively, and numerous filtering antennas have been proposed. [1][2][3][4][5][6][7][8][9][10][11][12] Generally, there are three commonly used design methods for filtering antennas, which are illustrated by the following three categories. In the first category, in addition to acting as a radiation structure, the antenna is also used as the last-order resonator of filter.…”

“…Filtering antennas can realize the functions of filtering and radiation simultaneously, which are widely used in various communication systems. Nowadays, filtering antennas have been studied intensively, and numerous filtering antennas have been proposed 1–12 …”

“…A bandpass filter with dual poles is designed, 1 and its last‐order resonator is replaced by a sector patch antenna to achieve the filtering function. In the second category, some filtering networks, such as loading parasitic strips 3,4 on the feeding line or defect ground structures, 5,6 are designed into the feeding circuit of antenna. A broadband filtering dielectric resonator antenna is proposed for its wide bandwidth and high gain 3 .…”