Dual-Polarization Frequency Scanning Microstrip Array Antenna With Low Cross-Polarization for Weather Measurements

The design of a dual-polarization frequency scanning array of microstrip patch antennas is presented. The coupling between the patch elements and the transmission lines is realized using microstrip directional couplers. Cross polarization suppression is achieved by applying a differential feed configuration to each element for the vertical polarization and an imaged feed arrangement with respect to the columns for the horizontal polarization. The antenna has been fabricated and test results are provided verifying the accuracy of the simulated results. In addition, the imaged feed configuration is used for two neighboring columns of the array to compensate for the spurious radiations and achieve a lower cross polarization level.