Abstract: A novel solar panel is disclosed which has a supporting substrate which is comprised of one or more plies of resin reinforced novoloid fabric.

Abstract: A tape recording/retrieving system includes a tape helically-wrapped about a cylindrical headwheel. When the headwheel rotates, the tape is hydrodynamically lifted above the rotating surface of the headwheel. A plurality of tape edge guides, illustratively three, disposed about the circumference of the headwheel, provide support surfaces for the tape. The edge guides include surfaces adjacent the cylindrical headwheel surface which are also subject to hydrodynamic forces when the headwheel rotates, causing the edge guides to "fly" away from the rotating surface, thus reducing wear problems on the headwheel and the guides. Using a knowledge of the system parameters, the edge guides are fabricated with a prestress so that they fly at a particular distance above the rotating surface which provides a supporting surface for the flying tape.

Abstract: An orbiting satellite system includes an asymmetrically deployed antenna and two deployable solar cell arrays. The solar cell arrays are deployed to a location which compensates for the asymmetry of the antenna so that the resulting station keeping thruster torques balance. Also, the system surfaces may be configured and the arrays so deployed to balance solar pressure torques on the system.

Abstract: A tubular circular cylindrical member, an attached frustro-conical member, and attached annular stiffening rings are formed of a metal matrix composite (MMC) material such as SiC/Al. The combined cylindrical and conical structure has a tapered wall thickness which reaches a maximum value at the point nearest the attachment of the structure to its launch vehicle. The entire structure and rings are quasi-isotropic, have a homogeneous microstructure, are low in weight, high in strength and stiffness, and are thermally stable with minimum distortion due to exposure to thermal cycling.

Abstract: A family of waveguide branch directional couplers having various coupling values is adapted for using the same housing dimensions for all members of the family. The housing includes a conductive block defining first and second spaced-apart parallel rectangular through waveguides. The block also defines a chamber extending between the through waveguides. One or more further conductive blocks in the form of rectangular parallelepipeds are fastened within the chamber and dimensioned to coact with the chamber dimensions to define at least two rectangular branch waveguides extending between the through waveguides. The dimensions of the further blocks are selected to adjust the branch waveguide dimensions to provide the various coupling values.

Abstract: A compact waveguide power combiner/divider is characterized by low reflection and dissipation losses. The device includes a radial waveguide having an inlet opening and a plurality of radial outlet openings, and a coupling pin is arranged in the radial waveguide to couple energy from the inlet opening with the radial waveguide. A mode suppression device is connected with the radial waveguide and contains a plurality of radially arranged slots corresponding with the outlet openings. A tuning mechanism arranged within the radial waveguide optimizes the coupling of undesired modes with the slots. An undesired mode absorption device is arranged in cooperation with the slots of the mode suppression device so that undesired modes are isolated from desired modes with low reflection and dissipation losses.

Abstract: A method is disclosed for exchanging a payload module on a satellite comprising a control module and a detachable payload for a new payload module in the STS or space shuttle orbiter using one RMS or remote manipulator system. In the method after the space shuttle orbiter is placed near the satellite the RMS rotates the new payload in a position to present the control module attachment end away from the cargo bay. The RMS then captures the satellite and positions it in the cargo bay of the orbiter adjacent the new module with the control module facing away from the cargo bay. The control module is moved to the new payload module and the assembly deployed in space away from the space shuttle orbiter.

Abstract: A communication system transmits information which may be in the form of frames or bursts of suppressed-carrier data over a dispersive transmission path which introduces multipath distortion. Each frame is stored as it is received and processed by iteratively simulating the multipath distortion, subtracting the distortion from the stored frame to form a corrected signal, and evaluating the quality of the resulting signal. The quality of the resulting signal is determined by frequency multiplying the corrected signal and evaluating the total power of components other than the frequency multiplied carriers. The iterative procedure adjusts the phase and, if deisred, the amplitude of signals tapped from a delay line.

Abstract: A signal transition detection circuit detects a transition which satisfies predetermined criteria related to magnitude and time. These criteria include that the magnitude of a group of signal samples preceeding the transition and a group thereof following the transition each be relatively close in magnitude and that the difference between the magnitudes of signal samples preceeding and following the transition be at least a predetermined amount. Further, detection criteria are included to test for smoothness and monotonicity of the transition and to exclude detection of transitions having magnitude changes exceeding a predetermined amount.

Abstract: A digital signal processing apparatus includes a digital coring circuit removing samples of digital input signals in a range determined by a digital threshold level signal. The threshold level signal developed by a coring control device is controllable according to the results of comparing at least a portion of the digital input signals to a digital reference level. In a television receiver having digital signal processing circuitry, for example, the coring range is decreased as the luminance signal level increases towards a brighter picture level and is increased as the luminance signal level decreases towards a darker picture level.

Abstract: A digital lowpass filter having controllable gain produces a filtered digital signal by adding to the digital input signal a feedback signal produced from the filtered digital signal. The feedback signal is produced by a delay element and by a gain element including a controllable shifter. The effective gain exhibited by the digital filter can be made to have values between the discrete values produced by the shifter by changing the shifter gain as a function of time.

Abstract: In a digital signal processing system, an analog-to-digital converter producing digital representations of an analog signal is dithered to increase its apparent quantizing resolution. Certain processing of the digital signals, however, can result in the loss of the dither information, because of either the form of digital filtering employed or the number of bits of the digital signals processed. To avoid the effects of such loss, the least significant bit of the digital signals is delayed and is applied to an analog output device to reintroduce a dither signal thereat having a magnitude substantially equivalent to that of the lost bit. The present invention is useful in processing digital television signals in a television receiver having a digital signal processing section.

Abstract: A digital signal processing system applies numbers to the multiplied or divided to address a memory storing a logarithm table to produce the logarithms of the numbers. These logarithms are added for multiplication or substracted for division to produce the logarithm of the result number which is applied to address a memory storing an antilogarithm table to produce the result number. The base of the logarithms is selected in accordance with the magnitudes of the numbers to be multiplied or divided so as to utilize substantially the entire range of magnitudes of the digital representation of the logarithms.

Abstract: A radio frequency (RF) amplifier including a resonant circuit having a peaked response is tunable in response to a tuning voltage to select RF carriers over a wide range of frequencies and includes an additional resonant circuit for improving its response at the low frequency end of that range. The additional resonant circuit has a peaked response tunable in response to the tuning voltage in tracking relationship to that of the first resonant circuit. The tracking relationship is desirably selected so that the additional resonant circuit does not become tuned to a frequency which is an integral sub-multiple of the frequency of a selected RF carrier.

Abstract: A television receiver which can display an on-screen indication of the number of the selected TV channel includes apparatus for providing such display automatically at times when the normal TV picture becomes blanked or black. In addition, the channel number display can be provided in small characters when the picture is normal and in enlarged characters when the picture is substantially black.

Abstract: A VHF television receiving antenna arrangement includes a cabinet having a loop of electrically conductive material disposed on its top, back and sides, preferrably on the inside surfaces thereof. A gap in the loop defines first and second feed terminals to which circuitry for tuning the loop connects. The loop is tuned thereby over at least a portion of the television frequency bands, responsive to a control voltage. Signals from the tuning circuitry are coupled to a television receiver tuner by a transmission line. Such loops can also have capacitors connected across tuning gaps for making the directional response of the loop more uniform at relatively lower frequencies (e.g. VHF channels 2-6) or switching diodes connected across control gaps for changing the directional response of the loop at relatively higher frequencies (e.g. VHF channels 7-13).

Abstract: A current amplifier includes six transistors of like conductivity on a substrate, the first and second transistors being diode-connected to receive input current, and the third and fourth having their main conduction paths serially connected with those of the first and second transistors, respectively. The gates of the third and fourth transistors are cross coupled with their drains. The gate-source connections of the fifth and sixth transistors are respectively connected in parallel with the gate-source connections of the third and fourth transistors. A potentiometer connects the respective sources of the third and fourth transistors to a common terminal for adjusting the relative portion of the input current in the aforementioned main conduction paths, thereby to proportionally adjust the drain currents of the fifth and sixth transistors.

Abstract: An operational amplifier includes a differential-input amplifier stage supplying first and second drive currents responsive to input signals applied to its input connections. A first current amplifier exhibiting gain factor G supplies currents to an output terminal responsive to the first drive current, and a second current amplifier exhibiting gain factor H supplies currents to that output terminal responsive to the second drive current. Each of the first and second current amplifiers includes means for switching the value of its respective gain factor G or H between a plurality of values responsive to a control signal, so the gain of the operational amplifier is programmable responsive to the control signal.

Abstract: A current mirror amplifier includes first and second transistors connected together at their common electrodes, the first transistor being connected for receiving input signal current at its output electrode, and the control electrodes of the transistors being connected for conditioning the second transistor for conducting a current responsive to the input signal current. Switch means, responsive to a control signal, selectively connects the output electrode of the second transistor to a supply terminal so the current gain between the input signal current and the current in the connection of their common electrodes switches responsive to the control signal.

Abstract: A differential-input amplifier suitable for the input stage of a CMOS operational amplifier has the capability of amplifying input signals with common-mode voltage components in a range including the entirety of its operating voltage. To provide this capability for one end of the common-mode range a long-tailed pair connection of depletion-mode field effect transistors with gates at the inverting and non-inverting input terminals of the amplifier is used; and to provide this capability for the other end of the common-mode range the substrates of the transistors are biased to operate them in effect as enhancement-mode transistors allowing their drains to work into a current mirror amplifier used for converting their balanced drain variations to single-ended form. Current mirror amplifier configurations are disclosed which are preferable for such conversion since they operate with reduced potential requirements, but are integrable in CMOS.