Combining InP and SiGe Technologies for Low Noise, Low Power Cryogenic Amplifiers suitable for Radio Astronomy Arrays and Quantum Applcations.

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