Abstract: Inductorless bias networks include a bias circuit having a bias return path which is coupled to and biases a variable impedance device in a relatively nonconductive state. Another bias circuit including a FET renders the variable impedance device relatively conductive in response to control signals so that one port is coupled to another port, for instance.

Abstract: An amplifier includes a first differential pair of transistors with commonly connected input electrodes also connected to a variable current sink. A common mode voltage control circuit includes a second differential pair of transistors, one of which has a control electrode coupled to the output electrodes of the first differential pair. The second differential pair provides control signals to the variable current sink to regulate the common mode output voltage. Current control circuitry is coupled to the variable current sink to allow adjustment of the gain, bandwith or power dissipation of the first differential pair.

Abstract: A passive, infrared, conical beam target sensor having multiple beams which may exhibit a wide variety of half conic angles is disclosed. The sensor may be utilized with a missile by positioning a plurality of optical assemblies adjacent to the skin of the missile and near a corresponding plurality of small windows in the skin of the missile. Each optical assembly includes a detector for each conical beam and a wide-angle lens oriented so that a lens axis parallels the axis of the missile. A preferred lens has a flat entrance aperture surface opposing a spherical surface. Unnecessary material is removed from the lens so that the lens axis may reside as close to the missile skin as possible. Each detector includes a plurality of photoelectric elements arranged to populate at least a portion of an annulus.

Abstract: A mechanical seeker for use in guided missiles utilizes two axes of rotation which are non-orthogonal to each other and to the longitudinal axis of the missile, and which converge at a point coincident with the center of mass of the antenna. This combination allows wide look angles of plus and minus 45 degrees or greater in a small envelope on the order of 5 inches or less in diameter.

Abstract: A logic level translator circuit includes capacitive coupling to facilitate rereferencing and differentiating of input logic signals. An input amplifier having complementary devices is responsive to the differentiated signals to provide control signals to a feedback circuit which holds one of the devices in a conductive state and the other in a non-conductive state to provide an output signal having predetermined logic levels. Threshold voltage generating circuits biases each of the devices.

Abstract: A power shutdown circuit includes an electronic latch circuit connected in series with a monitored power supply and comparator input and power terminals. The output terminal of the comparator is coupled to the control terminal of the latch. When a monitored signal magnitude crosses a threshold, the comparator provides a control signal which renders the latch nonconductive. A main switch device also connected to an output of the latch responds to the nonconductive state thereof to remove power from an electrical load.

Abstract: Amplifier circuitry includes a differential pair of transistors having commonly connected electrodes driven by a normally constant current supply transistor. Portions of the output signals developed by the differential transistors tend to vary with variations in the magnitude of a first power supply potential. A control circuit causes the magnitude of the normally constant current source to vary so that the other excursions of the output signal are substantially equal in magnitude to the first power supply potential to provide balanced signals across the load. A feedback circuit stabilizes the magnitude of the normally constant current supply transistors against variations in the magnitude of another power supply potential or in the constant current supply.

Abstract: The signal to be classified is sampled and the samples are multiplied by weighting functions prior to performing discrete Fourier transforms, power calculations, and normalization thereon so that the preprocessor is essentially a plurality of channel bandpass filter stages, the k-th one of which has a frequency response approximating an ideal filter defined by ##EQU1## where k=O, .alpha., 2.alpha., 3.alpha., . . . , r.alpha..alpha.=constant, 1.ltoreq..alpha..ltoreq.N/2r+1=greatest integer in N/.alpha.This preprocessor transforms blocks of one dimensional data into spectra in such a way that data blocks coming from similar sources will have spectra that are close to one another in spectrum space. The discrete Fourier transform is modified to remove or reduce the phase dependency problem and to enhance the clustering of similar spectra by the weighting function above.

Abstract: A resistive element is formed on a printed circuit board using only printed circuit board fabrication techniques. A substrate having a bi-metallic cladding on one side of the substrate and a conductive metallic cladding on an opposing side of the substrate is used. A predetermined trace pattern is formed in the metallic cladding. Resistive elements are formed in the bi-metallic cladding opposing their desired locations in the trace pattern. The bi-metallic cladding consists of a resistive layer between the substrate and a second conductive layer. Tabs are etched in the second conductive layer, then resistors, which couple various tabs together, are etched in the resistive layer. Plated holes connect the tabs to desired locations in the trace pattern located on the opposing side of the substrate.

Abstract: A radar device radiates and receives radio frequency energy pulses using an antenna having two independently driven major lobes. The two major lobes aim in two separate directions, and a third direction halfway between the two directions exhibited by the two major lobes represents an aim line of the apparatus. The antenna selectively radiates both circularly and linearly polarized pulses. Reflections received from circularly and linearly polarized pulses are compared to prevent a false indication of an object's centroid.

Abstract: A timing error estimator which samples a received stream of data symbols at the beginning, end, and a mid-point of a symbol period is disclosed. These samples are used with a model that assumes that a data stream waveform should transition along a straight line between its values at optimum sampling instances, separated by the symbol period. Differences between a mid-symbol sample estimated using this straight line model and the actual mid-symbol sample are assumed to be due to a timing error. The timing error estimator preforms computations on complex inputs and therefore is compatible with a wide variety of modulation types.

Abstract: A low power, astable multivibrator which operates on supply voltages as low as 1.5 volts and is suitable for controlling the application of power to power consuming electrical devices in battery-powered applications is disclosed. A transistor circuit which utilizes relatively large resistance values and positive feedback is presented. Resistance values are sufficiently large to bias transistors so that operation of the transistors in their saturation regions would be prevented without the application of the positive feedback.

Abstract: A projectile having a piercing front end with a solid lubricant molded on the front surface for reducing friction during penetration. The lubricant is molded in a shape to receive an antenna and other electronics. The front end also has an axial hole formed therein to enhance self destruction from the sudden release of compressional strain energy accumulated during penetration through a hard target.

Abstract: A radio frequency amplifier includes a bipolar and a field effect transistors (FET) which are cascoded for efficient operation and simultaneous gain control. Bias circuitry is connected to the control electrode of the FET to stabilize the output bias thereof. Negative feedback circuitry is connected between the output electrode of the FET and the control electrode of the bipolar transistor to stabilize the other bias levels within the circuitry. An AGC circuit is connected to the feedback circuitry to provide an automatic gain control function.

Abstract: A microwave absorbing ablating material is used as the ablative covering between the transmitting and receiving antennas while a standard ablating material, allowing the transmission of signals, is placed about the antennas. This allows signals to be transmitted from and received by the object covered by RF absorbing ablating material while preventing the transmission of signals transversely through the material. The RF absorbing, ablating material is made by combining an RF absorbing material with an ablating material in sufficient quantities to absorb and dissipate any signals that may be exposed to the ablative material.

Abstract: Improved logarithmic data compression is achieved by means of a method of finding a more efficient base and a more efficient memory structure. Data compression from a P-bit input word to a Q-bit output word is performed using an optimal base which produces a number of rounded logarithm values equal to 2.sup.Q when applied to all of the possible input values. These logarithm values are coded using the available output values to produce a logarithm look-up table. The look-up table is implemented using a multi-stage memory structure which reduces the number of memory devices required for a given table.

Abstract: An A/D converter which utilizes a plurality of series connected stages is disclosed. Each stage produces a single digital output bit. Errors are dynamically compensated utilizing alignment cycles. Error correction circuitry statistically analyzes an alignment signal during an alignment cycle. Various feedback paths form within each stage during an alignment cycle, and error compensation signals achieve optimum values which compensate for errors within each stage.

Abstract: Phase port gain compensating circuitry is coupled to the phase modulation summing circuit and voltage controlled oscillator (VCO) gain compensating circuitry is coupled to the frequency control terminal of the VCO. Compensator control circuitry utilizes divider ratio control information to control the characteristics of the two compensators to compensate for otherwise undesirable effects on the phase-locked loop response parameters caused by changes in the divider ratio and in the VCO gain.

Abstract: An apparatus and method is disclosed of providing higher quality speech transmission and reproduction. The present invention consists of a standard 2400 BPS transmitter with the addition of an additional 2400 BPS through a residual signal combined with the standard 2400 BPS signal. The addition of the residual signal gives more information about the speech signal being transmitted and allows more accurate reconstruction of the speech based on the received digital signal. The residual signal is adjusted to phase-align all frequency components to zero, then quantizing only the positive half of the residual signal now symmetric about zero time.

Abstract: An apparatus for performing a soft decision function prior to convolutional decoding in a data communication system using differential quadrature-PSK or other transmission schemes is disclosed. A memory element coupled between a demodulator and the convolutional decoder in a receiver portion of the communications system performs the soft decision function. The memory element contains data organized using probability of occurrence and Log-Likelihood parameters for each potential combination of current and past received signal modulation quantized at a predetermined level.