Two frequency heterodyne interferometer based on phase locked 2 - millimeter wave transceivers

The report presents the results of the design and description of the two frequencies heterodyne millimeter wave interferometer for measuring the linear integral electron density in the tokamak “COMPASS”. Microwave part of the interferometer based on solid-state transceivers with a phase locked loop. The interferometer consists of two solid-state transmitters and two millimeter wave receivers operating on 139,6GHz and 138,9GHz. Signals of oscillators and heterodyne receivers are synchronized by phase-locked loop system. The phase measurement is performed using a three-channel phase meter, based on programmable logic arrays (PLA). The interferometer provides information on the average electron density in plasma in real time and is used in the plasma discharge control system.