Pilot port - a quick and efficient technique for airborne monopulse receiver calibration

In airborne application where size and space are a constraint, reduced height waveguide are used to design the slotted waveguide array antenna. For the monopulse operation the comparator is an integral part of the antenna. Even though the comparator design is well tuned and optimized, after fabrication and integration with antenna, certain discrepancies in terms of loss and phase are inevitable. Moreover the deviation in loss and phase are unequal in different paths. To achieve maximum range and best possible tracking accuracy, it is mandatory to have prior knowledge about amplitude and phase imbalances in the sum and difference channels. This paper puts forward a simple yet efficient technique via a pilot port incorporated within the antenna and comparator layers.