Frequency-lock system for microwave local oscillators using molecular absorption lines

We describe the frequency-lock (FL) system for local oscillators in receivers in the 130 to 360 GHz range, using the resonance lines of molecules with a known absorption spectrum. The functions of a frequency discriminator, a diplexer, and a noise rejector are performed by a Mach-Zehnder interferometer with a gas cell. Deceased Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 11, pp. 1399–1404, November, 1998.