Spinning DF Antennas
The GTMR family of spinning DF antennas was designed for use on light aircraft and medium to large size UAVs using a common drive system with interchangable RF head assemblies based on the mission requirements.
The design specifications mandated the RF component reside within a cylinder under 12 inches in diameter and no higher than 8 inches to minimize drag, the assembly to weigh under five pounds and survivable up to 20g, and consume no more than 1.3A at 12V at startup with steady-state power consumption at or below 500mA. The antenna is self-disciplining by detecting the "relative zero" (the nose of the vehicle) on each rotation.
The associated DF processor operates in a Microsoft Windows® environment and utilizes one of three operator selectable algorithms to present a PPI display in real time, and digital DOAs for plotting the data on Google Maps® or other similar software.
The "Low Band" antenna operates from 20MHz-3GHz with a sub-one degree accuracy. The "High Band" antenna operates between 2GHz-18GHz with sub-half degree accuracy. In concurrent, related development is an HF version (2MHz-30MHz) and a hybrid that combines the High Band and the HF in the same physical envelope.
GTMR also has a spinning HF Antenna head in development. More information and pictures to follow as they become available.