Abstract: A radar system having a tactical mode and a calibration mode includes a transmitter section for providing high-power amplification of an RF pulsed waveform from an exciter during the tactical mode and the calibration mode. A circulator system has an input port connected to an output of the transmitter section and including first, second and third switchable junctions, and a high-power attenuator. The circulator system provides a transmit tactical mode signal path and a transmit calibration mode signal path of virtually identical electrical path lengths for a transmitter output signal, the tactical path passing through the first, second and third junctions in a first direction to an antenna I/O port, the calibration path passing through the first, second and third junctions in a second direction and through the high-power attenuator to an output port.

Abstract: A radar system having a tactical mode and a calibration mode includes a transmitter section for providing high-power amplification of an RF pulsed waveform from an exciter during the tactical mode and the calibration mode. A circulator system has an input port connected to an output of the transmitter section and including first, second and third switchable junctions, and a high-power attenuator. The circulator system provides a transmit tactical mode signal path and a transmit calibration mode signal path of virtually identical electrical path lengths for a transmitter output signal, the tactical path passing through the first, second and third junctions in a first direction to an antenna I/O port, the calibration path passing through the first, second and third junctions in a second direction and through the high-power attenuator to an output port.

Abstract: A method for evaluating the concentration of impurities in a semiconductor substrate. The method includes drawing together at least a portion of the impurities and measuring the concentration of impurities that were drawn together. In one embodiment of the invention, a gettering layer is formed adjacent one or more surfaces of the substrate to getter impurities from the substrate to the gettering layer. The impurity concentration of the gettering layer is then measured and the results are used to determine at least a range of impurity concentrations that were in the substrate prior to the drawing together.

Abstract: A method for evaluating the concentration of impurities in a semiconductor substrate. The method includes drawing together at least a portion of the impurities and measuring the concentration of impurities that were drawn together. In one embodiment of the invention, a gettering layer is formed adjacent one or more surfaces of the substrate to getter impurities from the substrate to the gettering layer. The impurity concentration of the gettering layer is then measured and the results are used to determine at least a range of impurity concentrations that were in the substrate prior to the drawing together.