An integrated quad-band RF front end for high-reliability small satellite missions

Abstract

As ever-increasing demand for lower size, weight, and power (SWaP) and small satellite platforms continues, it drives development in all sectors, including high-reliability and deep-space technologies. In order to meet these demands, JHU/APL is working to evolve its flight-proven, low-SWaP Frontier Radio (FR) [1] system into even smaller, more efficient, and yet more powerful designs. The Frontier Radio has already successfully flown an S-band version on NASA's Van Allen Probes (VAP) mission, and an X/Ka-band version will launch in summer 2018 on the NASA Parker Solar Probe (PSP) mission [2]. Building on this platform, a streamlined design was recently developed with small satellite architectures in mind. This resulted in a single-board radio that offers nearly the functionality of the main Frontier Radio with significant improvements in SWaP as well as FPGA reprogrammability, called Frontier Radio Lite (FR Lite) [3]. An L-band version of this with GPS receive capability is planned to launch in 2018. Now nearing completion is the development of a full spacecraft avionics suite centered on one powerful processing board, the Single-Board Computer (SBC). This SBC replaces the processing functionality of several disparate subsystems, creating vast efficiency gains. For radio functionality, the SBC implements the baseband and intermediate frequency (IF) processing in its FGPA while also providing the digitization for a separate analog front end, the RF Card (RFC). The RFC comprises dual, independent receivers and a single transmit IF capable of in-situ switching between higher-frequency outputs configurable for UHF through X-band and either a low-power (20 mW) output or a higher-power (1 W) output. This single card provides the RF hardware functionality of four traditional Frontier Radio slices. An X-band version of this design is planned to fly on an APL cubesat mission and is being investigated for NASA's Europa Lander mission. This paper discusses the design and advantages of the RFC in its role as the analog front end in the Frontier Radio Virtual Radio (VR), which also includes the SBC component. The Frontier Radio VR, along with the heritage Frontier Radio and FR Lite, rounds out a family of Earth-orbiting and deep-space radios that meet the needs of a diverse set of missions [4].