[This article belongs to Volume - 39, Issue - 04]

Phase Detector Free of Dead and Blinde Zones Applied in Monopulse Interferometer Systems

The principle of monopulse interferometer direction finding systems DF methods relies on locating the source of emission with a single received pulse. They measure the angle of arrival (AOA) of the intercepted signals using phase detectors (PD). PD measures the phase difference due to antenna spacing. In digital phase detectors, dead and blind zones caused by gate propagation delay are the most challenging factors. They cause sectors of error in phase differences measurements. In this paper, a digital phase detector using two XOR gates forming two channels has been presented. The dead and blind zone delays have been added to both channels simultaneously, which eliminated the effects of both factors. The output pulses of XOR gates representing the phase differences were counted using 1GHz digital clock and digital counters based on real-time monopulse processing. Multisim 14.2 has been used to simulate the proposed system with a 10MHz (100ns) input frequency and 50% duty ratio. The system has been tested for (0-50) ns phase differences. The output pulses are counted using 1GHz digital clock. The accuracy achieved is down to (1ns) which can be improved using a faster clock. Therefore, the proposed system is optimum for a mono-pulse interferometer system since it is free of dead and blind zones as well as the mono-pulse processing achievement.