At radio wavelengths, simultaneous spectral information is obtainable with heterodyne receivers.

In radio astronomy, heterodyne receivers are widely used in detection of the electromagnetic signals from celestial objects.

But quenching with overtones acts further as a heterodyne receiver mixing additional unneeded signals from those bands into the working frequency.

The instrument operated between 1994 and 2005 at the South Pole with four heterodyne receivers and three acousto-optical spectrometers.

A. E. Siegman, "The antenna properties of optical heterodyne receivers," Appl.

The JCMT is also equipped with three heterodyne receivers, which allow submillimetre spectral line observations to be made.

In heterodyne receivers, an image frequency is an undesired input frequency equal to the station frequency plus twice the intermediate frequency.

It was equipped with heterodyne receivers covering frequencies between 210 and 880 GHz, corresponding to wavelengths between 0.35 and 1.4mm, for observations of lines from the interstellar medium.

STJs are the most sensitive heterodyne receivers in the 100 GHz to 1000 GHz frequency range, and hence are used for radio astronomy at these frequencies.

Beacon track upgrades included radar circuitry to switch the heterodyne receiver to demodulate the transponder frequency, compensation for the transponder delay, and modification of the central's plotting board circuitry to allow display for increased ranges.

Examples of detectors common in spectroscopy include heterodyne receivers in the microwave, bolometers in the millimeter-wave and infrared, mercury cadmium telluride and other cooled semiconductor detectors in the infrared, and photodiodes and photomultiplier tubes in the visible and ultraviolet.