Executive Summary

This project develops an innovative drone-mounted millimeter-wave (mmWave) harmonic radar system for tracking invasive pest insects in Hawai‘i. The technology targets destructive species such as the coconut rhinoceros beetle and melon fly, aiming to improve early detection, optimize control strategies, and protect the islands’ ecosystems and agriculture.

Traditional harmonic radar systems are limited to short ranges and heavy transponders. Our approach integrates 12 GHz/24 GHz phased-array beamforming, miniaturized Nitinol-based transponders, and multi-drone coordination for long-range, real-time tracking of small, fast-moving insects—achieving high precision with minimal behavioral impact.

Research Objectives

Goal: Build and validate a UAV-mounted harmonic radar network for aerial tracking of invasive insects across complex Hawaiian landscapes.

Task 1 – mmWave Beamsteering Harmonic Transceiver

Design a compact 12 GHz phased-array transmitter using COTS modules and a heterodyne architecture for coherent beamforming.

Operates at 12/24 GHz ISM bands
Achieves >10 m range with lightweight, steerable arrays
Enables UAV integration for agile tracking

Task 2 – Ultralight Harmonic Tag

Develop a miniaturized 24 GHz transponder using a hollow bowtie antenna made of shape-memory alloy (Nitinol) and a Schottky diode for harmonic generation.

Tag weight < 1 mg for compatibility with small insects
Structural resilience through Nitinol’s superelasticity
Broadband harmonic reflection optimized for 12→24 GHz doubling

Task 3 – Multi-Drone Localization Network

Implement a distributed multistatic radar system using one TX and multiple RX drones for real-time localization.

Uses synchronized bistatic ranging and multilateration
Integrates GPS time sync and low-latency communications
Coordinates drone formations for continuous insect tracking

Broader Impacts

This system aligns with HISC priorities for early detection and rapid response (Priority 1) and technological innovation for pest management (Priority 2). It promotes cross-disciplinary collaboration among engineers, biologists, and agricultural scientists to create deployable surveillance tools for invasive species control.
Potential benefits include:

Reduced pesticide dependence through precise targeting
Enhanced monitoring of remote or forested regions
Scalable open-source framework for ecological sensing

Team

PI: Dr. Yao Zheng – mmWave radar, phased array, RF sensing
Co-PI: Dr. Haofan Cai – RFID and low-power tag design
Co-PI: Dr. Daniel Jenkins – UAV systems, autonomous sensing, precision agriculture

Collaborators include USDA-PBARC and NIWC Pacific for field validation and data integration.

Timeline (Dec 2025 – Nov 2026)

Phase	Period	Milestone	Lead
Phase I	Months 1–3	Frequency translator upgrade and system specification	UHM ECE
Phase II	Months 4–6	Phased-array prototype and beamforming validation	UHM ECE
Phase III	Months 7–9	Harmonic tag fabrication and field characterization	UHM ECE
Phase IV	Months 10–12	Multi-drone localization demo and final reporting	UHM ECE

Expected Deliverables

Functional 12/24 GHz drone-mounted harmonic radar prototype
Miniaturized Nitinol-based insect tags (< 1 mg)
Validated multi-drone localization system (> 100 m effective range)
Technical documentation and open-source dataset for future HISC programs

📡 Project Lead: yaozheng@hawaii.edu
🏛️ Institution: University of Hawai‘i at Mānoa – College of Engineering
🌺 Supported by: Hawai‘i Invasive Species Council (HISC) 2026–2027