Research on low-frequency ultra-wideband antenna design

Abstract

This dissertation addresses the challenges of broadband and miniaturization in low-frequency antennas, particularly for ultra-wideband applications, which are critical for modern wireless communication systems. The increasing demands for wide bandwidth and compact designs, driven by advancements in frequency hopping, spread spectrum technologies, and integrated circuits, necessitate innovative antenna solutions.

A novel double-layer folded floor monopole antenna is proposed, building on the theoretical foundation of biconical antennas. The design methodology is thoroughly discussed, and the influence of key geometric parameters on performance is systematically analyzed through electromagnetic simulations. To enhance impedance matching across a wide frequency range, a broadband matching network is designed using a direct optimization approach. Experimental results demonstrate that the proposed antenna, integrated with the matching network, achieves superior performance in terms of bandwidth, radiation efficiency, and miniaturization compared to traditional monopole antennas.

Furthermore, structural modifications, such as horizontally extending the cone ends, are introduced to increase the electrical length without enlarging the physical size. This approach effectively balances broadband performance and miniaturization, making the antenna well-suited for UWB applications where space and performance are critical.

Despite these advancements, the study acknowledges limitations and outlines future research directions. These include the need to account for complex electromagnetic environments in antenna modeling and the consideration of practical non-ideal components in broadband matching networks. The findings of this work highlight the potential of the proposed techniques for developing high-performance, miniaturized UWB antennas, contributing to the advancement of next-generation wireless communication systems.