Abstract: An integrated active array antenna system is disclosed which comprises a "sandwich style" microwave packaging scheme that includes three principal layers: an antenna layer, a transceiver layer, and a beam forming sub array layer. These three layers are arranged in a coplanar geometry, with connections between the layers being in the form of microwave vias. Each transceiver module may be implemented in the form of a single Monolithic Microwave Integrated Circuit, and each beam forming sub array may be similarly implemented. The coplanar geometry and use of Monolithic Microwave Integrated Circuit technology provide for multi-beam active array of very shallow physical depth.

Abstract: A radar system is provided with first and second moving target indicator (MTI) systems. The first MTI system generally works better against ground clutter than against sky clutter. The second MTI system works well against sky clutter but generally requires a greater number of radar return echoes to discern targets in the sky clutter. A correlation estimation circuit is employed to calculate the correlation of clutter-like return echoes not suppressed by the first MTI system. If the return echoes are sufficiently correlated, the second MTI system is invoked against the clutter. If the return echoes are less well correlated, on the other hand, then electronic counter-counter measure systems may be invoked.

Abstract: A CW pseudo-random-coded (PRC) radar system including a triple-clock arrangement. The three slightly different clock frequencies are sequentially employed to generate the bi-phase coded RF transmissions and the received echo signals are separately bi-phase de-modulated by code bit. Clutter filtering and sampling in both I and Q channels by a commutating element are employed. Video processing, preferably of the FFT type, is provided as is range-ambiguity processing. The system provides resolution of range ambiguities over a long total range permitting the PRC word length and other system parameters to be optimized for elimination of Doppler ambiguities.

Abstract: A digital compensator for radar transmitter instabilities for use in a digital MTI system. The I and Q coherent phase detector outputs are continuously monitored for phase, amplitude and timing instabilities and arithmetic correction signals are generated and applied to the digitized received signal values to compensate for these instabilities which are particularly characteristic of pulsed magnetron transmitters, for example.