Application of DGS in H Format for Suppression and Attenuation of Higher Order Modes in Microfita Antennas
Harmonic Suppression; Higher-Order Mode Control; Microstrip Antenna; DGS
This thesis aims to characterize the DGS H filter to attenuate higher-order modes in microstrip antennas. The DGS H is designed independently of the antenna. The initial dimensions of H will be calculated using the desired attenuation range. After design and analysis of the filter response, the DGS H will be integrated into the antenna. The integration allows to eliminate filters between the signal source and the antenna. The reduction of insertion losses is the main advantage among others. The H filter is investigated through the frequency response. The dimensions of H (weights and bar) were parameterized from the initial dimension proposed here, which makes it possible to control the rejection band from the modes to be attenuated. This thesis presents the characterization of the DGS filter in H format for applications in microstrip antennas as well as a method to calculate the initial dimension of H. Two antennas were designed to prove the effectiveness of the proposal. These antennas are designed for the S and C bands (2.45 and 5.80 GHz). The results show the attenuation of the higher-order modes for the Microstrip Antennas studied in this thesis. The simulated and measured results are presented and discussed. The excited modes are investigated through the modal fields and frequency response. Prototype measurements were performed using a vector network analyzer (VNA) and an anechoic camera.