Bell Telephone Laboratories Maser Amplifier |
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Little did the engineers depicted in this Bell Telephone Laboratories advertisement in a 1959 issue of Radio-Electronics magazine know the significance the "Sugar Scoop Antenna" they were erecting at the time would play in the world of astrophysics. Their intention, following the recently completed International Geophysical Year (IGY) efforts, was to design and build a system for characterizing the Earth's atmosphere in preparation for satellite communications. A cutting-edge, cryogenically-cooled ruby-based maser amplifier operated in the 5,600 MHz realm with thermal noise in the 18K region. Undoubtedly lots of good information was gleaned, but the most notable result from that antenna was the discovery in 1964 of the Cosmic Microwave Background (CMB) radiation by Bell scientists Drs. Robert W. Wilson and Arno A. Penzias. The pair was surveying the sky in the microwave spectrum and noticed that regardless of where the antenna was pointed, there was always a fairly constant level of "noise" that could not be removed from the system. It occurred to them that they had stumbled upon the very electromagnetic signature of the early post Big Bang universe. The rest, as the saying goes, is history. Articles here on RF Cafe which mention the Dr. Robert W. Wilson and Dr. Arno A. Penzias are The Maser & Sugar Scoop Antenna: Receiver for Signals from Space, Bell Telephone Laboratories Project Echo, The Amazing Maser: The Jewel That Conquers Space, Cosmic Radio Signals from Sun and Stars, and Sugar-Scoop Antenna. Bell Telephone Laboratories Ad
Another Step Toward Space Communications The above antenna is part of a new ultra-sensitive radio receiving system under development at Bell Telephone Laboratories. It has extraordinary directivity. Beamed skyward, it ignores radio "noise" from the earth, yet picks up extremely weak signals from outer space. The signals are amplified by the latest Bell Laboratories "maser" amplifier. The maser principle was first demonstrated, using gas, by Prof. C. H. Townes and his collaborators at Columbia University. Bell Laboratories scientists applied it to the solid state guided by a theoretical proposal of Prof. N. Bloembergen of Harvard University. Their latest traveling wave maser amplifier employs a ruby mounted in a waveguide. The ruby is excited to store energy. As signals pass through, they absorb this energy and are thus amplified. The device uniquely combines the characteristics needed for practical space communication: extremely low inherent noise and the ability to amplify a broad frequency band. At present the receiving system is being used to pick up and measure minute radio noise generated by the atmosphere. It also foreshadows important advances in long distance communications. For example, it could extend the range of space-probe telemetering systems, could help make possible the transatlantic transmission of telephone and TV signals by bouncing them off balloon satellites - and has numerous applications in radio astronomy and radar. This pioneer development in radio reception is one more example of the role Bell Laboratories plays in the pursuit of better communications technology. Bell Telephone Laboratories World Center of Communications Research and Development
Posted August 2, 2022 |
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