A novel monopulse planar array using CSRR slots

The design of planar array for monopulse tracking applications is proposed which generates sum or difference far-field patterns. In this letter, the radiating elements are split-ring slot on the upper of radial waveguide. The slots designed to radiate right-hand circular polarization in the X-band. The feeding network consists of four coaxial probe which generated sum or difference pattern by changing the probe phases. The gains of sum and difference pattern are better than 16 dB and 10 dB, respectively. The null depth of difference pattern is less than -45 dB.