Using the EHF Transceiver Module for Designing Contactless Encoder

The paper considers the possibility of using an EHF transceiver module for designing contactless encoder [1]. It is shown that the development of contactless encoder based on Doppler effect [2], [3] involves using a microwave oscillation of sufficiently high frequency as a reference signal to ensure the necessary measurement accuracy. The expression for the target's speed has been derived, showing that with an increase in the reference frequency, the frequency at the Doppler receiver's output increases, and so does the target's speed.A structural diagram of the contactless encoder has been developed. The possibility of creating a voltage-controlled oscillator (VCO) with the use of the Gunn-effect diode second harmonic mode to design EHF transceiver module is considered for the first time. A signal processing unit has also been developed, which consists of an electronic circuit that converts the periodic signal from the transceiver module (Doppler frequency signal) into a square wave of the same frequency and uses the duration of the square pulse to determine the received frequency for transmitting it through the serial port (USB port) to PC. The following results were obtained: a wavelength range of 5 mm, an electrical retuning range of over 2 GHz, a continuous output power of the transmitter in the range of electrical retuning of over 5 mW. The possibility of designing a Doppler effect microwave encoder, which allows determining the location of objects with sub-millimeter accuracy, is shown.