Platform Embedded Slot Antenna Backed by Shielded Parallel Plate Resonator

Abstract

A new cavity architecture for applications in design of resonator-backed slot antennas with a height less than <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\lambda/15$</tex> </formula> profile is presented. This architecture renders cavity heights as low as <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\lambda/130$</tex> </formula> and small lateral dimensions. Miniaturization of the supporting cavity resonator is achieved by meandering the passage from the bottom of the cavity resonator to the slot aperture. Unlike conventional cavity resonators, the proposed design operates in a TEM mode which allows for wider bandwidth operation and miniaturization of lateral dimensions. Ultrasonic consolidation technique is employed to fabricate the complicated cavity structure monolithically. Measurements verify the proposed antenna exhibits excellent gain and front-to-back ratio (FTBR). Wide-band mode of the antenna is achieved by using a carefully designed microstrip feed across the slot aperture which facilitates a fictitious short along the slot aperture. The antenna is then flush-mounted onto an arbitrarily built metallic platform and is shown to feature consistent impedance matching. The FTBR is found to improve when the antenna is embedded into the platform. The same antenna architecture is redesigned for VHF band operation using standard multi-layer PCB technology and consistent functionality is verified.