A Low-Profile Filtering Antenna Using Slotted Dense Dielectric Patch

Abstract

A low-profile filtering antenna using a thin dense dielectric patch (DDP) with a pair of silver-coated slots is investigated in this letter. The dominate TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">101</sub> mode of the DDP owning the similar characteristics of the traditional microstrip patch is directly excited by the microstrip line for antenna design. The silver-coated slots etched along the polarization direction, as a key technique in the proposed design, can not only generate a lower band radiation null directly, but also shift high-order TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">111</sub> mode down (close to the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">101</sub> mode) to build an upper band null since the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">111</sub> mode is nonexcitation and nonradiation. Accordingly, a good filtering performance of the proposed antenna without any additional circuits is obtained due to the two radiation nulls located on both sides of the antenna's operation band. For demonstration, a prototype is implemented and tested. The simulated and measured results are given, showing good agreement.