Compact wideband multi-arm 3-D wire antenna for GNSS applications
Résumé
In this paper, a novel multi-arm crooked wire antenna designed with a multi-objective genetic algorithm (MOGA) is presented. The proposed topology offers a small size, lightweight, and a wideband −10 dB impedance matching. Its fully metallic nature preserves a high radiation efficiency. The multi-arm topology is discussed, and the impact of the number of arms and segments is studied. A proof of concept is optimized, fabricated, and tested. It occupies a volume less than 0.11 λ × 0.13 λ × 0.14 λ, where λ is the wavelength at the lowest operating frequency and covers the entire Global Navigation Satellite System services frequencies with a bandwidth of 503.5 MHz which represents 35.56%, without any matching network. The antenna’s fully metallic structure results in a radiation efficiency higher than 98% and a gain of 8.66 dBi. Measurement results agree with simulations and are elaborated around the frequencies of the lower (1164–1300 MHz) and upper (1559–1610 MHz) bands of the L-band spectrum. A realization-friendly fabrication technique is proposed to realize the 3-D multi-arm wire antennas with high accuracy. The rigid fully metallic structure makes the antenna very suitable to operate in harsh environments, as in aerospace and military applications where substrate-based antennas are unqualified.