A novel monopulse edge-fed microstrip array antenna

The design and performance of an novel edge-fed microstrip array antenna are introduced, which generates sum and difference far field patterns for monopulse tracking. Each microstrip line array is fed at the edge side with the middle of the row shorted. A compact slot patch antenna element loaded with a pair of spirals is proposed, which is 40% smaller than the conventional half-wave patch antenna. The -19dB side-lobe level of sum pattern and 37dB null depth of difference pattern have achieved in the experiment.