Title: RF-photonics 94GHz LO and Front-End for Earth Science Radars
Presenting Author: Razi Ahmed
Organization: Jet Propulsion Laboratory
Co-Author(s): Dmitry Strekalov, Vladimir Ilchenko, Nino Majurec, Anatoliy Savchenkov, Andrey Matsko, Simone Tanelli

Abstract:
We describe the development of a resonant RF-photonic receiver that efficiently upconverts a weak microwave signal, like millimeter-wave radar cloud and precipitation echoes from a spaceborne platform, to the optical frequency domain. This architecture requires less demanding instrument size, weight, and power than traditional direct high-frequency microwave detection and down-conversion approaches. By employing a resonant photonic receiver, the device achieves signal power amplification with very low noise temperature, leading to greatly improved instrument sensitivity compared to the current state-of-the-art. Additionally this device generates a very high-quality W-band (93GHz) LO, also using RF-photonics, that surpasses performance of traditional oscillator implementations with ovenized oscillators and multipliers while also being more compact. The LO subsystem generates a 93GHz RF-LO used to generate a high quality transmit signal as well as the LO that is used in the receiver to downconvert the signal to IF. These factors combined, make way for a new generation of ultra-compact, highly sensitive radars suitable for Smallsat and Cubesat form-factors. We present theoretical analysis and numerical simulations supporting the photonic approach to millimeter-wave detection using high-quality nonlinear optical resonators, as well as preliminary results from lab experiments.