Miniaturized UHF Module-Integrated Antenna With RF-Based Detection for Multi-Objective UAV Applications

In this paper, we propose a system with a miniaturized antenna structure in the 915 MHz band that can place a circuit or module with a battery in the center. The circular folded dipole antenna placed at the rim of a circular substrate is designed to account for interference from a centrally placed circuit and battery. A matching loop is connected to both arms of the dipole, and a lumped element impedance matching circuit is added to cancel the imaginary impedance generated in the design for miniaturization. And, an LC balun is also implemented to connect it with the single-ended RF IC of the system. The simulated proposed antenna has a 10 dB impedance bandwidth of approximately 1% at 915 MHz, a reflection coefficient of -18.9 dB, and a maximum antenna gain of 1.12 dBi. The diameter of the proposed system is $0.12 \lambda_{0}$. To verify the operation of the proposed system, a circuit to display the incident RF power was added to measure the RF power incident to the system.