Low-Cost Phased Array Feed System for Radio Astronomy and Wide-Angle Scanning Applications

Abstract

A low-cost antenna array feed system for 15.4-20.0 GHz is presented. The dual linear polarization, 24- element antenna array and feed network are constructed from single substrate layers, include substrate integrated waveguide- to-microstrip transitions, and coaxial connectors. The individual antennas are arranged on an x-y grid through a metallic backplane that mechanically supports the array and electrically provides a ground plane which reduces back lobes of the end-fire beams and improves directivity. The planar antipodal dipole antenna elements and metal backplane are assembled into a dual linear array, and tested. The phased array's measured results, which are ±40□ scanning range in azimuth and elevation, cross-polar values of 18 dB, wide operating frequency range and flat gain, make the proposed antipodal dipole antenna a viable low-cost candidate for phased array antennas and for use in radio astronomy and wide-angle scanning applications. Measurements are in good agreement with simulations, thus validating the design process.