Miniaturized wideband dual‐polarized microstrip patch antenna with improved radiation performance

Abstract

A miniaturized wideband dual-polarized microstrip patch antenna with enhanced radiation performance is proposed in this letter. First, eight parasitic patches loaded are employed in order to achieve apparent compact size. Then, four parasitic substrates are introduced to further decrease the resonant frequency of the antenna for size reduction. More importantly, the cross-polarization (cross-pol) is significantly reduced as the electric field at the edge of the radiation patch is balanced via these parasitic elements. After that, two coupled lines and transition lines placed on the substrate are connected by the probes, resulting in forming a new mode to effectively broaden the impedance bandwidth, and offer a good impedance matching. With these improvements, the volume of the antenna element is only kept of about 0.0032 λ03 (λ0 is the free space wavelength at the center frequency). Meanwhile, its bandwidth is obviously enhanced to about 15.8%. Finally, the 1 × 4 antenna array is fabricated and measured to validate the predicted performance. It presents that the impedance bandwidth of the array is about 18.8%. Besides, its dimension (0.0324 λ03) is only about 0.119–0.58 times of these previous works. Particularly, the wide HPBW and low cross-pol are successfully acquired during the operating band.