A compact wideband dual-polarized antenna with harmonic suppression using nonuniform defected ground structure

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 × 0.6λ₀² (λ₀ 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.