Radio telescope receivers for ALMA
By Critical Comms Staff
Monday, 19 March, 2012
Daniels Electronics has successfully completed a $1.3 million contract with the Canadian government for the assembly and test of radio receivers used in the National Research Council of Canada (NRC) development of 84-116 GHz heterodyne receivers for the international Atacama Large Millimeter Array (ALMA) telescopes.
ALMA is located at 5000 m elevation in the Chajnantor Plain of northern Chile. The resolution and sensitivity of the array will provide a leap forward, making it a pre-eminent radioastronomy facility.
NRC’s contribution to the project included 73 extremely sensitive 84-116 GHz receivers. The nucleus of the receiver is a superconductor-insulator-superconductor (SIS) tunnel mixer which downconverts the RF signal collected by the radio telescope to an intermediate frequency (IF) signal centred at 6 GHz with a bandwidth of 4 GHz.
A cryogenic high electron mobility transistor (HEMT) amplifier is used to amplify the IF signal by more than 30 dB before it is delivered to the ALMA back-end system. The SIS detector and the HEMT IF amplifier must operate at a cryogenic temperature of 4 Kelvin. NRC has developed a cryogenic 4-8 GHz HEMT amplifier for this application.
The US National Association of State Chief Information Officers has set successful implementation...
To mark 100 years of Finland's independence, Finnish amateur radio operators are being...
University of Liverpool researchers are trying to devise liquid antennas that are small,...