Research On Filtering Antenna Design Methods Based On Mode Utilization

With the rapid development of cutting-edge technologies like 5G mobile communication,the demands for radio frequency front-end components in modern wireless devices are becoming increasingly stringent.Filtering antennas,which integrate radiation and filtering functions,hold great research potential in meeting the requirements for integration,low power consumption,and multifunctionality in wireless systems.The existing design methods for filtering antennas can be broadly categorized into two types:the filter-centric method and the antenna-centric method.Compared to the filter-centric filtering antenna design method,the antenna-centric filtering antenna design method offer higher integration and lower insertion loss,making it more favored by designers.However,the current antenna-centric design method heavily relies on trial and error and empirical analysis,resulting in limited filtering methods and a lack of comprehensive understanding and effective design strategies.As a result,the antenna-centric design method lack universality and flexibility.In light of these limitations,this study focuses on investigating the antenna-centric filtering antenna design method.By exploring the relationship between antenna filtering characteristics and mode characteristics,a systematic design method is proposed to overcome the shortcomings of existing methods.The feasibility,superiority,and applicability of the proposed approach are discussed through representative design examples that address various performance requirements.The research findings demonstrate the efficacy of the proposed method in effectively addressing the limitations of existing approaches.1.A new design method for filtering antennas is proposed,which integrates the radiation and filtering characteristics by constructing desired filtering modes and suppressing interfering modes while utilizing the inherent filtering properties of the antenna.The research focuses on the resonance method and excitation filtering method for desired modes,as well as the resonance suppression method and excitation suppression method for interfering modes.2.A research study is conducted to investigate the design method of frequency-bandselectable filtering antennas,addressing the application requirements of wireless communication technology.The study proposes an approach based on mode utilization,which involves constructing new passband desired modes or suppressing unnecessary passband modes to achieve integrated design of the target passband and out-of-band filtering characteristics.Based on this method,two filtering antennas are designed to operate in the selected frequency bands of 5G N3(with a relative bandwidth of 4%)and5G N77(with a relative bandwidth of 24%),serving as representative target passbands.The feasibility of the method is validated through these designs.3.A research study is conducted to address the limitations of existing fusion design methods in designing dual-polarized filtering antennas,including constrained design thinking,complex antenna structures,and difficulties in structural debugging.The study focuses on the design method of dual-polarized filtering antennas based on mode utilization,which involves constructing desired orthogonal degenerate modes and suppressing interfering modes.Based on this method,the study designs two dualpolarized filtering antennas with simple structures and excellent performance by optimizing the antenna radiation mode or synergistically utilizing the antenna feeding structure mode.These results confirm the feasibility and superiority of the proposed method in achieving dual-polarized filtering antennas.4.A research study is currently underway to investigate the design method of filter array antennas based on mode utilization in order to address the challenge of simultaneously optimizing radiation and filtering performance in existing filtering antenna arrays.Two design approaches have been proposed.The first approach involves integrating unit structure modes,feeding structure modes,and array topology designs to create filter array antennas.The second approach utilizes high-performance filter unit antennas for designing filter array antennas.Based on these approaches,two filter array antennas have been designed to achieve high aperture efficiency,high passband radiation efficiency,and excellent out-of-band filtering characteristics.These designs confirm the feasibility and superiority of the mode utilization method in the design of highperformance filter array antennas.In conclusion,the mode utilization method proposed in this study offers a new design option for addressing some of the issues associated with existing antenna-centric filtering antenna design methods.It provides a solution for the design of filtering antennas and contributes to the realization of effective filtering antenna designs.