An Optimized Multiband Antenna for UWB Ad Hoc Networks Based on Topology Optimization Theory

Nowadays, benefiting from high accuracy, low power consumption, and high bit rate, ultrawideband (UWB) techniques have been applied widely on indoor positioning and ad hoc networking. However, as an important component of UWB systems, the mainstream design methods for antenna are still the combination of UWB radiation structures based on equivalent circuits. In this article, to achieve multiband aperture sharing, we propose a topology optimization method for the radiation structure of antennas for UWB ad hoc networks based on an improved genetic algorithm (GA) and trust region framework. In addition, we fabricate the optimized multiband antenna, measure its performance in an RF shield box, and take an experiment based on a four-node UWB ad hoc network. Through the quantitative analysis of simulation and experimental results, we found that the fabricated antenna achieves high isolation, a large front-to-back ratio (FBR), and an impedance bandwidth of 81.2% with a small size. In addition, the antenna can also absorptive bandpass filter (ABPF) and separate signals of different frequency bands on cross-polarization components. The above features help us reduce out-of-band interference and increase the maximum communication distance on the UWB ad hoc networks.