Radio astronomers usually try to detect very weak signals emitted by objects very far from Earth. Instruments used in land -based radio astronomy are large antennas or antenna networks equipped with the most sensitive receivers available, i.e., the noise they produce should be minimal to avoid its overlap to the signals received. Usually radio astronomy receivers are cooled to very low temperatures since some of the electronic devices used to amplify or mix radio signals add less noise if they are cooled.
In the frequency range of 500 MHz to 50 GHz , the components most often used at the entrance of these receptors are amplifiers with high electron mobility transistors (High Electron Mobility Transistors - HEMTs ) . These devices can be cooled to cryogenic temperatures (~ 15 Kelvin = -258° Celsius) for minimal noise. Once the weak radio astronomy signal is amplified, it is relatively immune to noise added in later processes.
For higher frequencies, the input signal is first converted to a lower frequency by a mixer and subsequently amplified by a cryogenic HEMT. In modern heterodyne receivers for millimeter and submillimeter wavelengths (up to several hundred GHz) the mixer is typically a SIS junction ( Superconductor - Insulator - Superconductor ) cooled to the temperature of liquid helium (4 Kelvin = -269° Celsius ), while at the THz range the so-called hot electron bolometers (Hot electron bolometers - HEB ) used are cooled to even lower temperatures.
Laboratories at Yebes Observatory have modern instrumentation for the design, construction and testing of receivers and microwave components up to a frequency of 50 GHz. Available are scalar and vector analyzers, power and noise figure meters, etc. Also available is equipment for performing refrigerated (cryogenic) receptor tests at temperatures down to 15 Kelvin (-258 ° C).
A machine shop equipped with machine tools complements the electronics laboratory.