A wide-band monopulse comparator with complete nulling in all delta channels throughout sum channel bandwidth

A broad-band monopulse comparator with complete nulling in the three delta channels throughout the sum channel bandwidth is presented in this paper. It is based on a new broad-band 180/spl deg/ hybrid with amplitude and phase balances that are theoretically perfect and frequency independent. Using this 180/spl deg/ hybrid, a microstrip monopulse comparator was realized on a low-cost FR-4 board. The comparator was fully characterized by its eight-port S-parameters to generate the sum and delta channel frequency responses. Over 30-dB null depths was achieved in the three delta channels across the sum channel passband from 1.1 to 3.3 GHz.