Cosmic Microwave Technology, Inc. — National Aeronautics and Space Administration SBIR Phase I: S11

Description

Future earth science and planetary science missions will require large pixels, highly sensitive radio astronomy receiver arrays.nbsp; Recent breakthroughs in detector technology are leading this growth.nbsp; To achieve the required sensitivities, the large number of pixels (thousands) in a receiver requires low noise, low power cryogenic amplifier arrays. nbsp;Lower noise amplifiers result in higher sensitivity arrays.nbsp; The capacity of cryogenic coolers is limited, requiring amplifiers to have a low power dissipation.nbsp; Producing cryogenic amplifiers that has both low noise and low power is difficult.nbsp; Today, cryogenic amplifiers are manufactured using either Indium Phosphide (InP) HEMT devices or Silicon Germanium (SiGe) BJTs.nbsp; Amplifiers based on InP technology have noise temperatures as low as 1.5K with a power dissipation of 10 mW.nbsp; SiGe based amplifiers have noise temperatures of 3-4K with a power dissipation of 300 uW. The noise temperature of an amplifier is primarily set by the first stage.nbsp; The subsequent stages contribute very little to the noise of the amplifier.nbsp; Therefore, combining InP and SiGe will result in the ultimate low noise, low power cryogenic amplifier.nbsp; The ideal amplifier will have a InP first stage for low noise and a SiGe 2nd and 3rd stage for low power.nbsp; The InP stage will be a discrete design for optimum performance.nbsp; The SiGe stages will be MMIC based design for ease of manufacturing and low cost.nbsp; Combining these two technologies will result in an amplifier with 2K or less noise with a power dissipation of 500uW or less.nbsp; Imagine an antenna array of 1028 elements that has a power dissipation of 514 mW.nbsp;nbsp; This performance is possible with this innovation. Phase 1 will result in a design of a low noise, low power amplifier based on both theoretical and empirical measurements