Abstract: An improved high power vertical MOS transistor is disclosed. The channel region of the transistor is electrically connected to the source terminal. The active region of the transistor comprises a plurality of finger-like mesas extending at approximately right angles from a second palm-like mesa. The finger-like mesas form the active regions of the transistor with the palm-like mesa serving as a support for the source bonding pad. Thin metallic stripes extend along the edges of the finger-like mesas to form the gate of the transistor. A metallic layer contacts the gate and extends up at least one edge and along the top of a substantially rectangular mesa. The finger-like, palm-like and rectangular mesas are supported by a common substrate. The portion of the metallic layer overlying the top of the rectangular mesa serves as the gate bonding pad. Electrical contact to the drain region of the transistor is made through the supporting substrate.

Abstract: A system for transmitting a secure television image is as disclosed. At the transmitter each line of the television image is digitized to generate a series of digital numbers representing the complete video line. The digital numbers representing the picture portion of each scan line are cyclically rotated by a random amount leaving the synchronizing portion unchanged. The digital numbers are converted to an analog signal which is filtered to generate a composite signal with the picture portion of each line cyclically shifted by a random amount. At the receiver the signal is digitized and the picture portion of each line is rotated to restore the picture portions of each line to their original position. The process of rotation is identical to that used at the transmitter except that the amount of rotation must be adjusted to restore all portions of the picture portion of the signal to their original position.

Abstract: A complementary MOS logic circuit is disclosed. The circuit utilizes two stages with a coupling network comprising a capacitor and a diode used to couple the first stage to the second stage. This results in a circuit with the logic signal coupled to the input being inverted at the output without introducing substantial loss in signal amplitude.

Abstract: A monitor for checking a plurality of multi-bit digital patterns generated by a system being monitored to determine that each pattern is valid, that each of the patterns appear in the right sequence and that the total number of valid patterns detected during the testing cycle is as expected is disclosed. Additionally, the bit patterns are monitored to detect unexpected transitions. The results of these tests are then combined to form a composite malfunction signal indicative of the operational status of the system being monitored.

Abstract: A low level class D amplifier is disclosed. High effeciency is assured by operating the active devices in the switching or class D mode and recovering substantial portions of the power contained in the harmonics generated. The amplifier includes a switching circuit or class D active circuit, a harmonic impedance circuit and an RF circuit serially connected across a power supply for supplying DC power to the amplifier. During the conducting state of the class D active circuit, the harmonic impedance circuit limits the harmonic currents and stores energy as a magnetic field. Substantially all of the stored energy is recovered during the non-conducting portion of the active circuit and returned to the DC power supply. Limiting harmonic currents reduces the dissipation of the active devices. Recovering the stored energy substantially improves the efficiency of the amplifier.

Abstract: An MOS transistor constructed using silicon on sapphire technology in which the channel region can be electrically connected either to the source or drain terminal is disclosed. The transistor is advantageous in that the shift of the threshold voltage of the transistor in the presence of radiation is substantially decreased. Connecting the channel region of the transistor to the source terminal also substantially reduces what is normally referred to as the "kink" effect in MOS transistors utilizing floating substrate channel regions. Reducing the sensitivity to radiation and the kink effect results in a transistor having improved electrical characteristics.

Abstract: An N-channel MOS transistor wherein two layers of different dielectric materials (e.g., silicon dioxide and silicon nitride) are used in conjunction with a P-doped silicon gate to permit the use of a higher resistivity P-type substrate. This enables a higher junction breakdown voltage and a higher threshold voltage without a reverse bias on the substrate due to an increase in the work function difference between the gate and substrate. Because of the lower concentration (i.e., higher resistivity) of the substrate, high frequency response is increased due to lower drain-source capacitance.

Abstract: A system for controlling the output power of a transmitter which communicates with a remotely positioned receiving station through a "linear" transponder such that the power level of the input signal to the transponder is substantially constant is disclosed. The output signal of the transmitter and the input signal to the transponder includes two carriers having predetermined relative power levels with respect to each other. Typically, one carrier will be 10 dB below the other. Since all linear transponders are slightly non-linear, intermodulation distortion products are generated by the transponder. The intermodulation products and the two carriers are retransmitted to the receiving station by the transponder. The power level of the intermodulation distortion products relative to the low power carrier is measured at the receiving station.

Abstract: Digital control apparatus for automatically slewing i.e. orienting a directive antenna to a quasi-stationary transponder such as a synchronous satellite in orbit above the earth wherein appropriate drive signals for the elevation and/or azimuth axes are provided in response to the received signal from the transponder until the peak or substantially maximum signal strength is sensed. Operationally, digital logic circuitry utilizes the characteristics of the antenna beam pattern to detect the approach toward zero slope near the peak of the pattern to slew the antenna to the peak signal.

Abstract: A circuit arrangement for protecting the remainder of a plurality of parallely operated transistors in the event any one of the transistors fails in a shorted condition. An open circuited failure has no adverse effect upon the operating circuit. Each transistor includes a "slow" turn-off diode with respect to the period of the input drive signal, coupled in series between a common input signal-feed point and the base of the transistor to which it is connected. The diodes are poled to block the collector B+ supply potential appearing at the base of the respective shorted transistor, thus preventing the B+ supply potential from being applied to the base of the remaining transistors. Additionally, a respective fusister is connected in series between each emitter and the load circuit line in order to thereafter remove the failed transistor from the circuit and to balance the transistor currents during normal operation.

Abstract: A multi-function information system utilizing a specialized modular information library is disclosed. In its preferred embodiment, the system is applied to the problem of teaching technicians the theory of specific apparatus and providing a tool to aid in the location and correction of malfunctions of the apparatus. In such an application, the system may comprise a video playback system and a video-cassette library containing a description of how the apparatus operates and malfunction correction procedures. Special procedures are employed in constructing the library to assure that the teaching and malfunction correction times are minimized.

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.

Abstract: A system for evaluating members or a family of similar devices by comparing images of a model device to the image of the member to be evaluated is disclosed. An image of the model device is first produced and stored in a memory. An image of the member to be evaluated is produced as the stored image of the model device is simultaneously reproduced. The images of the model and the member being evaluated are compared to generate a comparison signal related to the differences therebetween. The comparison signal is sampled at a predetermined rate, to produce a digital signal indicating sample points where the comparison signal exceeds a predetermined value. Statistical techniques are used to analyze the digital signal to determine which portions of this signal correspond to significant differences between the images of the model device and the member being evaluated.

Abstract: A monitor for disabling a selected operative function of the battery powered vehicle when the battery reaches a predetermined discharge state is disclosed. The discharge state of the battery is determined by continuously monitoring the terminal voltage of the battery. Automatic scaling circuitry is included so that the monitor automatically adjusts to the range which is appropriate for the battery being monitored. Two warning signals are generated with each warning signal indicating a progressively lower discharge state of the battery. After the second warning signal has been on for a predetermined time period, a selected operative function of the vehicle is disabled. If the vehicle is a fork-lift truck for example, the lift mechanism might be disabled however the main drive motor could remain operative so that the truck could be returned to the battery charging station. The monitor also prohibits the disabled function from being reenergized except when a fully charged battery is installed in the vehicle.

Abstract: A system for controlling and maintaining the power output of a broadcast transmitter under varying line voltage conditions, including a pulse width modulator wherein a triangular wave acting as a reference input is compared to the audio input. Power is controlled by varying the amplitude of the triangular wave relative to the audio input which additionally includes a DC bias thereby increasing or decreasing the comparator square wave output duty cycle which output is used to control the transmitter's RF power amplifier. Three separate DC control inputs, respectively, for automatic power control, remote or local manual power control, and a slow start control are summed and fed to an operational DC amplifier which provides a composite DC output which is fed to a triangular waveform generator in order to control the amplitude of the triangular waveform generated thereby.