Experimental Patch Antenna
Building and testing a 70 cm patch antenna for satellite communication, including circular polarization techniques.
Description
This web article by VK3BLG details the construction of an experimental 70cm (432 MHz) circularly polarized patch antenna, intended for satellite communication. The resource provides dimensions, feed point specifications, and impedance matching considerations for a single patch element, with discussion extending to array configurations for circular polarization. Construction involves a copper patch element on a dielectric substrate, fed via a coaxial cable.
The design is based on information derived from AO-40 satellite antenna specifications, focusing on achieving circular polarization for satellite reception. The article includes specific dimensions for the patch and feed points, along with impedance values. Validation is implied through on-air satellite reception reports, with initial signal reports of 1 S-point above noise for AO-40 beacons using a grid reflector, improving to 3-4 S-points above noise with a 2-turn helical feed. The author references a NanoVNA for impedance measurements and discusses the relationship between slot and dipole antennas in the context of patch design.
DXZone Focus: Web Article | 70cm Patch Antenna | On-Air Satellite Reception | Circular Polarization