Abstract: A microwave transition consisting of a stripline member coupled to a pair of slot lines deposited on the outer surfaces of a pair of contiguous dielectric rib members. The stripline and one slot line on one of the rib members cross each other at right angles on parallel planes forming an energy coupling junction. One end of both slot lines comprise slot line regions which are either smooth tapered or stepped out to the full width of the dielectric ribs so as to couple RF energy to the normal fields in a twin toroid phase shifter which in one embodiment the toroids extend past the cross-over junction while in the second embodiment two additional dielectric layers are contiguously applied to the outside surfaces of the dielectric rib members containing the slot lines for matching the electric fields in the slots to the toroids. The outer surfaces of the transition including the twin toroids are metallized and fitted into a metal sleeve which provides support for the composite structure.

Abstract: A secondary radar uses monopulse reception techniques to improve the estimate of the aircraft position and to improve the reliability of the reply decoding process. Digital signal processing techniques are utilized to replace the analog circuit used in the prior implementations. The secondary radar implements monopulse processing using a half angle phase method wherein the sum and difference signals are encoded in a complete phasor. The detection of the signal and extraction of the azimuth angle data is implemented using a digital receiver concept. The complex phasor is sampled at an intermediate frequency, down converted to baseband and detected. The azimuth angle is computed using arithmetic methods implemented by digital signal processing circuitry.