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1958 - atomic amplifier - first to demonstrate unilateral (one-way) gain in microwave energy by means of two electrically isolated cavities connected only by a beam of neutral ammonia gas molecules

PHILCO MASER - "ATOMIC" AMPLIFIER

E&MP 91.004

Oscilloscope

June 22, 1958

"Atomic" amplifier, shown above [right] is the first to demonstrate unilateral (one-way) gain in microwave energy by means of two electrically isolated cavities connected only by a beam of neutral ammonia gas molecules.

As the oscillating molecules pass through the second cavity, electromagnetic radiation is developed and appears in the output waveguide.

Thus is achieved unilateral amplification without aid of electronic effects.

Philco Research has set a new first in the development of a special type of gas Maser, also known as an "atomic" amplifier, it was revealed today. Allen C. Munster, Director of Research for the Government and Industrial Division, said the Maser study is being conducted for the Army Signal Engineering Laboratory, Fort Monmouth, N. J. and is an important part of the Army's pioneering work in this field.

Mr. Munster credited this breakthrough in the field of "atomic" amplifiers to the creative leadership of William F. Bradley, Philco's Director of Technical Research and paid tribute to C. T. McCoy and Nisson Sher who headed the Philco Maser project.

The Philco Maser is the first "atomic" amplifier to demonstrate unilateral (one-way) gain of microwave energy by means of two electrically isolated cavities connected by a beam of neutral ammonia gas molecules.

Energy is transferred from one electromagnetically isolated point to another by the flow of these molecules. As the oscillating molecules pass through the second cavity, electromagnetic radiation is developed and it appears in the output waveguide.

Thus is achieved unilateral amplification without aid of electronic effects.

The original concept of amplification and oscillation by uncharged molecules through use of a Maser was demonstrated by Columbia University in 1955.

Prior to the development of the Philco "atomic" amplifier, all Maser amplifiers were basically bilateral devices and had all the problems of common input-output terminals.

This two-cavity Maser research study is part of Philco's pioneering effort in the field of low-noise communication microwave amplifiers and radar systems.

Just as electronics has achieved its greatest versatility and reliability through the inherently unilateral amplifying property of vacuum tubes and transistors, the new unilateral Maser promises equally important applications for atomic amplifiers.

Masers have excited the electronics industry because they remove the noise inherent in conventional electronic devices.

They can provide amplification approaching the theoretical limit of no extraneous noise. It is the noise in an electronic system that produces the static on radio and the white fuzz (snow) on the television screen.

The Philco Maser also has demonstrated the predicted physical phenomenon of prestimulation of molecules in an excited state.

Prestimulation in a two-cavity device promises to provide a greater degree of freedom for controlling the gain-bandwidth properties of an "atomic" amplifier.

Masers are still on the threshold of a scientific frontier, but soon new systems will be evolved. Their successful operation will depend either upon very low noise amplification or very high oscillator stability which represents a dramatic technological break-through for electronic components.

PHOTO 58-24/6-11


Original Caption by Science Service
© Philco Corporation Philadelphia



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