Monopulse RLSA Antenna with Gap-Waveguide Feeding Network for Space Debris Radar at 94 GHz

This work presents the design of a monopulse antenna with left-handed circular polarization that is based on a radial line slot array (RLSA) antenna excited by a distribution network implemented in gap waveguide. This feeding network consists of a Butler matrix that excites a circular cavity coupled to the RLSA, simultaneously generating a sum beam and a difference beam. The application of the antenna is a radar for space debris detection financed by the Community of Madrid. The RLSA disposes the radiant elements in the form of concentric rings in which the length and position of the slots are optimized by an algorithm based on the Method of Moments. The RLSA is placed on the feeding network, which has been designed oriented to additive manufacturing. The simulation results of the entire antenna show acceptable matching and very stable radiation patterns for monopulse operation.