A Compact Wideband Dual-Polarized Antenna with Harmonic Suppression Using Nonuniform Defected Ground Structure

Abstract

A wideband dual-polarized coplanar waveguide (CPW) fed antenna integrating a wide stop-band filter is presented. The designed filter is based on a nonuniform defected ground structure (DGS) in order to obtain a wide stop-band and a compact size. This filter is used to reject harmonics and spurious radiation arising from the RF front end. The complete structure (antenna and filter) has been optimized to have a compact size of 0.6 × 0.6 2 0 ( 0 being the free-space wavelength at the lowest operating frequency). The realized antenna operates in the frequency range between 2.7 GHz and 5.9 GHz (bandwidth of about 74%). The isolation between feeding ports is more than 18 dB. The complete structure has a wide stop-band characteristic (103%) for harmonic rejection. The simulated numerical results have been confirmed with measurements.

Optimization and Design of Wideband Antenna Based onQFactor

“…𝑄 factor is applied to the computation of a wideband antenna in this paper. In order to introduce 𝑄 factor to the case of wideband antennas [19,20], we need to start with the most primitive expression of 𝑄 factor. According to related literature [21], for arbitrary radiator, the expression of 𝑄 can be written as…”