This proposal is responsive to NASA SBIR topic S14.03 Remote Sensing Instrument Technologies for Heliophysics; specifically, the last bullet item related to “Technologies for precise radiometry at terahertz bands…, particularly at 4.7 THz.” Through this proposed SBIR effort, VDI will develop the technology to realize an all-solid-state heterodyne receiver at 4.7 THz with suitable frequency resolution, sensitivity, and SWaP for Heliophysics applications in low Earth orbit on SmallSat and CubeSat platforms. The Phase I work is a combined simulation/experiment design study to prove the feasibility of the technology to achieve the SBIR topic requirements and generate the exact plan to achieve these requirements through Phase II. The receiver will be based on a Schottky diode mixer with a local oscillator (LO) source based on high frequency power amplifiers and a chain of frequency multipliers. By the conclusion of the Phase II effort, a prototype receiver system will have been developed and characterized in a laboratory environment (TRL 4) and delivered to NASA for use as a prototype or engineering model (EM) for future Heliophysics missions. This prototype will also be designed to be suitable for space-qualification and will become the basis for a commercial line of receivers for SmallSat and CubeSat applications across the 1 – 5 THz range.
The primary NASA application is Heliophysics, specifically the measurement of the OI line in Earth’s atmosphere through limb sounding at 4.7 THz. The Schottky receiver will have sufficient frequency resolution, sensitivity, and SWaP for this important application. When combined with the recent demonstration of compact heterodyne receivers at 870 GHz and 2.5 THz for IceCube and SSOLVE, respectively, this effort will demonstrate complete coverage from below 1 THz through 5 THz for NASA’s atmospheric research programs.
There is an emerging market for SmallSat/CubeSat-based atmospheric remote sensing technology. Compact receivers with advanced functionality can also benefit imaging systems for portal security. Higher frequency receivers will also extend the frequency range of commercial test & measurement equipment, for example frequency extenders for spectrum and signal analyzers.