Pseudo-Random Noise Radar n Prototype Design –Small inexpensive “correlation-type” receiver –Digitally produced Pseudo-Random Noise (PRN) for transmitter –Upconversion Board –Low-Profile Ultra Wide-band Synthetic Aperture Antenna Array

PRN Generator n The heart of the system

PRN Generator (cont’d) n PC Controlled n Produces two identical pseudo-random waveforms with a user-defined delay between. n Through software, delays can be manipulated to scan entire delay span, partial delay span, or any points therein. n Bandwidth of output noise dependant only on clock-speed of PRN circuit

Upconverter n Basic circuit to convert base-band noise to transmission spectrum of GHz.

Optional BPF Filter Board n Can be used to replace Upconverter if large amplification of PRN harmonics is used. n Currently Not used in system

Receiver / Antenna Array

Antenna Array n Gain of 8+ dBi n Side-by-side elements can be used for isolated measurements (SAR) due to high isolation. (20dB 1st Adjacent - 30dB 2nd Adjacent) n Usable Bandwidth on order of GHz

Antennas (cont’d)

Receiver n Small - inexpensive –Each channel only requires mixer chip, op- amp chip, RF amplifier chips and discrete components (resistors etc) n Analog integration allows data collection on the order of milliseconds, and reduced noise through averaging. n Preliminary tests show minimum detectable signal at -80dBm.

Prelim RX Testing Experiment

System Integration

First System Test

First System Test (cont’d) n SNR non-optimal due to drastic op-amp output drift with temperature n Problem remedied with low-drift op-amp n No range data taken yet after improvement, but 45dB reduction in noise floor recorded

From here... n Fabrication of improved PRN Generator will provide 7 inch downrange steps to a maximum of 280 feet. n 4 Antennas and Receivers increased to 40 for Synthetic Aperture Imaging n Other possible applications for PRN radar