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Portable Harmonic Radar TransceiverPortable Harmonic Radar TransceiverTeam Members: Mikeoll Echeverria, Maria Gomes, Juan Lopez

Faculty Advisor: Marinos Vouvakis

Abstract

Understanding the movements of small animals and insects is critical to biology and entomology. Typically the tracking of such organisms is done by attaching RF transmitters at their body. The biggest challenge in RF tracking these animals is the large size and finite battery life of radio transmitters. This project presents a compact harmonic radar system for the detection of such organisms without the need of RF transmitters, while been functional in cluterous environments.

Principle of OperationThe radar generates a signal with one frequency component at 780 MHz. This signal is sent through the transmitter. The receiver antenna will detect a signal with a component in the second harmonic of the fundamental frequency (1560 MHz ). This new signal can only be received if the sent signal hits a nonlinear device with enough power to send back another signal strong enough to be detected.

Harmonic Radar: (a) Transceiver module (b) Antenna: Transmitting (large dipoles) and Receiving (small dipoles) Yiagi-Uda

antennas (c) Digital Interface (detector )

Department of Electrical and Computer EngineeringECE 415/ECE 416

SENIOR DESIGN PROJECT 2007College of Engineering - University of Massachusetts Amherst

System Block Diagram: Radar Block Diagram (top) and Digital interface (right)

Technical Characteristics

(b)

(c)(a)

Results: (a) Antenna Results: 3D antenna patterns and graphs of transmitting and receiving antenna return loss (b) Detection Results: Frequency domain graphs when tag detected and not detected (c) Tag (d) Overall System: illustrating signal with and without detection

(a)

Range 10 metersTag Size 8 cm

Tag Weight 5 g

Angle of Resolution

30 degrees

Mic

roco

ntro

ller

DC SignalDC Signal

(d)

TX Signal 780MHzTX Signal 780MHz

AttenuatorAttenuatorAmpAmpVCOVCO

VCOVCO

LNALNALNALNA LNALNA Power DetectorPower Detector

RX Signal 1560 MHzRX Signal 1560 MHz

Transmitter Receiver

Transmitter

Receiver

LED

Target Detected

Acknowledgments: We would like to thank: Fernando Rodriguez-Morales, Pei-Sang Tsai, Justin Creticos, Eric Marklein, Ana Sastre, Professor Paul Siqueira, Professor Dennis Goeckel, Richard Winn , Francis Caron, Keith Shimeld, and Professor Marinos Vouvakis. You made this project possible .

(b)

LED

Tag

No tag

LED

Target Detected

(c)