Contactless Measurement of Angular Velocity Using Circularly Polarized Antennas

Abstract

An innovative method to measure the angular velocity using circularly polarized antennas is proposed. Due to the properties of circular polarization, the angular velocity is frequency modulated (FM) on a wireless carrier. This enables a low-cost precise continuous measurement of angular velocity using a standard FM demodulator. The hardware can be easily adapted for both high and low angular velocity values. The precise alignment angle between the antennas can be determined if the initial antenna orientation is known. The angular error is shown to be <;1.5° for antennas with a 1-dB axial ratio. The basic method is applicable for a fixed distance between the antennas. Therefore, an advanced method that provides data for variable distances is also presented.