Available at: https://digitalcommons.calpoly.edu/theses/1675
Date of Award
MS in Electrical Engineering
Dean Y. Arakaki and John A. Saghri
Several previous Cal Poly thesis projects involve synthetic aperture radar (SAR), automatic target recognition (ATR), and tracking. SAR data was either accessed from a publicly available database or generated using complex computer modeling software. The motivation for this dual thesis project is to design and construct a scaled SAR system to support Cal Poly radar projects. Ideally this is a low-cost, high resolution SAR architecture that produces raw range Doppler data for any desired target area. To that end, a scaled SAR system was successfully designed, built, and tested. The current SAR system, however, does not perform azimuthal compression and range cell migration correction. These functionalities can be pursued by future students joining the ongoing radar project.
The system built for this thesis is a 1 GHz bandwidth SAR system. The system is comprised of analog/RF front end circuitry, two antennas, a mechanical rail platform, power supplies, an oscilloscope, and control and image processing software. This thesis covers the design and evaluation of the analog/radio frequency (RF) front end circuitry and signal processing software.
RF amplifier integrated circuits (ICs) were evaluated for two purposes: increasing transmitted signal strength and improving system signal-to-noise ratio (SNR). A voltage-controlled oscillator’s (VCO) tuning characteristic and bandwidth were measured to verify its ability to support system specifications. A ramp generator circuit was designed, assembled and tested. Multiple ultra wide band (UWB) band pass filters were investigated for received signal image rejection. A low pass filter (LPF) was designed, assembled and tested for noise reduction. The overall system was tested with multiple known target locations.
This thesis is a joint project with Ryan Green, MSEE student. To understand the entire project, refer to both thesis documents. The overall project is covered broadly in both papers but each report specializes in selected areas. Ryan Green’s thesis document focuses on the system control software, antenna design, and mechanical rail platform.
This thesis document focuses on the RF circuitry, analog circuitry, and image processing. The introductory section introduces radar system concepts and the SAR system layout. The remaining sections describe component designs, component performance and system results.