Date of Award

Spring 2011

Document Type

Thesis

Degree Name

Doctor of Philosophy (PhD)

Department

Electrical, Computer & Energy Engineering

First Advisor

Zoya Popovic

Second Advisor

Tom DeGrand

Third Advisor

Dejan Filipovic

Abstract

This thesis addresses the design and characterization of a pulse Doppler radar designed to detect targets at short range (R ≤ 7m). To minimize the shortest detectable range, a subnanosecond transmitted pulsewidth is desired. UWB design techniques were combined with a pulse Doppler radar architecture to demonstrate a full radar, including the transmitter, receiver, simulated channel, and post processor.

The transmitted pulse train has a 2.5GHz carrier frequency, a 730 ps pulsewidth, and a 1GHz 10 dB-bandwidth. The PRF of the radar is 20 MHz, which allows unambiguous range and Doppler detection with a single PRF. The peak transmitted power is 1.2W. The characteristics of the transmitted waveform provide fine range accuracy (δR = ±0.03m), facilitate a short minimum range, and allow for an efficient transmitter design. The receiver was designed to complement the transmitter; it has a homodyne architecture and is pulsed to isolate a specific detectable range.

A closed-loop channel model was designed to simulate the range delay, Doppler shift, and channel attenuation of a moving target; the model is connected to the transmitter and receiver with coaxial cable, facilitating bench-top characterization of the radar and eliminating some effects of wireless transmission, such as multipath. Extensive closed-loop radar testing was performed, and the following radar characteristics were determined: (1) The minimum detectable SNR, assuming a 36.5 μs integration time, is 0 dB. (2) Assuming a transmitter-to-receiver isolation of 80 dB, the minimum range of the radar is R[sub]min = 1:3m+R[sub]lk, where R[sub]lk is the apparent leakage range between the transmitter and receiver. Depending on the antenna system design, the radar can detect targets from 1:5m ≤ R ≤ 7m, meeting the original goal of this work. These results support the supposition that a UWB pulse Doppler radar architecture can be employed for short-range, moving target detection.

Comments

possible sci. notation issues in abstract:

≤ δ ± μ R[sub]min R[sub]lk

Jane Z. 13 Jan. 2016

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