Integration of microwave and millimeter wave bandpass filters with antennas
Filters and antennas are essential elements in communication and radar systems. In a conventional design, antennas and filters are designed independently and then connected together through transitions and/or connectors, which introduces loss and increases the size of the design. Filter and antenna integration can be implemented using the resonance characteristic of the antenna and the coupling between the antenna and resonator of the filter, which effectively removes the transitions between the filter and antenna and improves the overall system performance. In this thesis, two different types of filter and antenna integrations are investigated. First, the Substrate Integrated Waveguide (SIW) filter integration with dielectric resonator antenna (DRA) in millimeter-wave frequency range is presented. SIW is used to design the bandpass filter and serves as the feeding structure for DRA. Design integration with improved radiation efficiency is achieved by replacing the last resonator of the filter with DRA. The synthesis procedure is presented in detail. Equivalent circuit models are developed to facilitate optimizations of the design. In addition, integrated designs of parasitic DRA and DRA arrays with SIW filters are developed. All designs have been simulated and fine-tuned using full wave solver. Simulation and measurement results are presented.