Date of Award:

8-2022

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Electrical and Computer Engineering

Committee Chair(s)

Reyhan Baktur

Committee

Reyhan Baktur

Committee

Charles Swenson

Committee

Bryan Willis

Abstract

Radar is important in target tracking, imaging, and weather prediction applications. As technology is increasingly miniaturized, there is a push for smaller radar. Research and exploration in outer space also benefit from small, low-power technologies. The NASA Jet Propulsion Laboratory’s RainCube was the first successful CubeSat-borne radar. A CubeSat is a type of small satellite that conforms to specific size and weight standards. Radar technology benefits from additional research on how to further miniaturize radar payloads.

Integrating the transmit and receive antennas on the solar panels removes the need for antenna-deployment mechanisms, preserving space on the CubeSat. This thesis also demonstrates that implementing a radar that transmits and receives continuously and simultaneously (continuous-waveform) on the CubeSat improves the sensitivity, size, weight, and power consumption of the radar. Continuous-waveform radar suffers from self-interference because the transmitter and receiver are on at the same time.

To overcome the self-interference, the transmitter and receiver must be isolated. Physically separating the antennas helps provide the isolation required for continuous-waveform radar, but is limited by the small size of the CubeSat. Isolation can be further increased by designing the antennas with opposite circular polarizations. The interfering signal traveling directly between the antennas has a different polarization than the receive antenna is designed for, so the interference is suppressed. The signal that hits a target reflects with the opposite circular polarization, so when it arrives at the receiver it has the proper polarization, so it is not suppressed. Combining physical-separation and different-polarization isolation enables a novel solution to implement a continuous-waveform radar on a small platform like a CubeSat.

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