Abstract: The invention is an improved integrated circuit chip assembly which provides enhanced heat transfer from active electronic devices of the integrated circuit by significantly reducing the thickness of the substrate and providing the necessary structural support through a thermally conducting spacing segment between the substrate and a ground plane in the region of the active electronic devices. This improvement further permits added flexibility in the design of transmission lines by permitting adjustment of the distance between the transmission line and the ground plane and furthermore by permitting the introduction of a second dielectric material such that the impedance of the transmission line may be controlled.

Abstract: Coupling module for use with phased-array antenna systems. The module includes separate phase shifters for the transmit and receive paths through the module. The transmit path also includes a power amplifier and the receive path includes a small signal, low noise amplifier. The two paths are coupled to the antenna radiating element by a transmit-receive switch or by a microwave circulator. A conducting septum is located between the devices in the transmit and receive paths to increase the isolation between the two paths. The individual phase shifters are optimized for unidirectional flow of comparatively large or small microwave signals and for the degree of desired phase shift resolution. By using vector modulators for the phase shift devices, the amplitude of the signal in the path can be compensated for temperature and frequency variations in the path.

Abstract: Transversal characteristic filter using a magnetostatic-wave device having amplitude weighted transducer assemblies. The input transducer includes a multi-fingered conductive layer with each finger being equally dimensioned and spaced. Each finger is separately connected to a contact of a field effect transistor integrated onto a semiconductor chip. A separate transistor is available for connection to each finger. The contact widths of the transistors vary depending upon the location of the connected finger from the center-most finger. A distribution approaching sin(x)/x is desirable in most applications. At the output or combining end of the device, the transducer fingers are separately connected to the gates of individual transistors whose junction widths vary symmetrically about the width of the junctions of the transistor connected to the center-most finger.

Abstract: Generally, pulsed radar transmitters of the solid-state variety generate rectangularly shaped RF envelope pulses having discontinuities in the rise and fall edges thereof. It has been identified that, while maximizing power radiation efficiency, these sharp rise and fall times additionally provide for excessive energy in the spectral sidelobes about the transmission frequency of the radar signal. This excessive spectral sidelobe energy has been found to degrade the performance of closely operating pulsed radars through mutual interference. The present invention provides for pulse shaping control in a solidstate transmitter of a pulsed radar for reducing the spectral sidelobe energy being transmitted. The control is directed to modulating the shape of the rectangular RF envelope pulses to have substantially continuously rising and falling edges.

Abstract: The invention comprises a microwave oscillator using a stripline circuit. The active device utilized in the oscillator is a bipolar transistor. A microstrip circuit is coupled to the emitter of the transistor while the collector is coupled to ground. This generates a negative impedance characteristic at the base of the transistor at the operating frequency. The operating frequency is determined by a varactor which is series tuned with an inductor. The impedance of the series tuned circuit is transformed to match the input impedance of the transistor by a microstrip circuit. Microstrip isolation circuits are utilized to couple appropriate bias signals to the emitter and the base to establish the proper operating point for the bipolar transistor. The output signal is taken from the base circuit of the transistor through the series combination of two microstrip circuits and a capacitor. A second varactor is loosely coupled to the base circuit of the transistor to provide for fine tuning.

Abstract: A microwave combiner assembly is described incorporating a coaxial transmission line having a plurality of diodes exhibiting negative resistance at high frequency mounted between the center conductor and the outer conductor of the transmission line. Each diode is mounted on a segment forming a portion of the center conductor which are separated by slots containing lossy dielectric. A signal is capacitively coupled from each diode by capacitively coupling each segment to a common center conductor. Each diode is biased by coupling a bias voltage to each segment. The microwave combiner overcomes the problem of mechanically assembling a plurality of diodes in an oscillator or amplifier while attenuating anti-phase currents in the diodes indicative of undesired oscillator modes.

Abstract: A pulsed microwave power amplifier for radar transmitters having a class B operated first stage field effect amplifying transistor, which is gate biased to pinch-off in the absence of an input pulse is disclosed. The drain current pulse induced in response to the input RF signal appears as a voltage, which is stepped up through a Ruthroff transformer to turn on a bipolar transistor which switches a gate of a second stage field effect transistor from pinch-off voltage to a voltage corresponding to the drain current substantially equalling 1/2 I.sub.DSS to operate class A for the second stage of amplification. A third stage of amplification may be utilized, wherein its field effect transistor, which is also biased to pinch-off is operated in response to the amplified signal.

Abstract: A two stage transmission notch filter characteristic is achieved with one stage of microwave circuitry. Elimination of the second stage is accomplished by reflecting the microwave power back through a single stage device. Structurally, the adjacent ports of two 3 dB directional couplers are directly connected by delay lines of unequal delay times. The opposite adjacent ports of one coupler comprise the device input and output while the opposite adjacent ports of the other coupler are terminated in a manner that reflects microwave power back through the device. A phase shifter is inserted into one delay line for tuning and a non-reciprocal phase element is used to prevent reflected signals from emerging from the input port.

Abstract: A system for determining the use of an ECM jammer against a bi-frequency radar utilizing a spin echo matched filter. Portions of two simultaneously transmitted radar RF pulses of different instantaneous carrier frequencies are coupled to a non-linear element which produces a composite pulse signal containing predetermined intermodulation product frequencies. This composite pulse signal is utilized as the input pulse to a spin echo system which has a locally generated postset pulse applied a predetermined time thereafter. The radar return signals are coupled to the spin echo system which produces a spin echo correlation signal upon the reception of an ECM radar return pulse which inherently contains substantially the same predetermined intermodulation product frequencies.