Abstract: A method for manufacturing an equalizer. The method first acquires a transmission line scattering-parameter, and a gain of the transmission line scattering-parameter at a frequency 1 ? ? ? ? , in which the gain represents an ideal gain; next, performs an integration about the transmission line scattering-parameter, the ideal gain and an equalizer scattering-parameter, and performs a differentiation about the transmission line scattering-parameter and the equalizer scattering-parameter to get the component impedances of the equalizer. Then manufacture the equalizer circuit with the derived component impedances.

Abstract: An integrating apparatus to lower the levels of audio outputs of an on-board audio system immediately upon cessation of a noise level such as when a vehicle comes to a stop. Audio signals from an audio source are amplified through attenuating means by an amplifying means to drive a loudspeaker. An output of a microphone for detecting a noise is inputted to each of two integrating circuits, which have different fall time constants. Outputs of the integrating circuits are applied to a selectively outputting means, which selectively derives an output having a lower level among the outputs of the integrating circuits, and which then supplies the output as a control signal to the attenuating means. When the level of noise is high such as when the vehicle is running, the control signal has a high level and the attenuating means reduces an attenuation. Thus, the output of the audio source may be heard without a drift of the audio signal level.

Abstract: The invention relates to a circuit device for realizing a non-linear reactive elements scale network, wherein the non-linear elements of the network are pairs of inductive and capacitive components cascade connected between a pair of input terminals and a pair of output terminals. Advantageously in the invention, each component of the network is formed by cascade connecting a first and a second transconductance integrator with each other.

Abstract: A calibration circuit adjusts a differential output voltage from a line driver circuit when the differential output voltage falls outside a specified tolerance range. The calibration circuit includes a sample and hold circuit which samples the differential output voltage and holds a representative signal. A comparator compares the held signal with a reference voltage signal. When the held signal is greater than the reference voltage signal the comparator outputs a LOW signal and when the held signal is less than the reference voltage signal the comparator outputs a HIGH signal. The comparator output signal is stored in a memory circuit of a control logic. The control logic instructs an up/down counter to increment when the comparator output is LOW and to decrement when the comparator output is HIGH. A calibration current source sinks a unit of calibration current when the comparator output is LOW and sources a unit of calibration current when the comparator output is HIGH.

Abstract: A passive cylindrical integrator assembly is disclosed which provides an output voltage into 50 ohm load that is proportional to the time integral of the input voltage. The device has a bandpass of greater than 1000 MHz plus and a risetime which is less than 350 picoseconds. The device produces negligible overshoot for very fast rising and falling signals. The construction of the device uses low cost materials and is configured into a cylindrical shape. The cylindrical housing concentrically supports front and rear connectors or center pins. Each center pin is connected to a 470 ohm 1/4 watt resistor. The resistors are in turn held in place by a screw and nut in contact with the graphite material which fills the center of the cylinder. A dielectric film surrounds the graphite material insulating it from the outer housing wall.

Abstract: The present invention relates to a system which uses information in a certain band of frequencies, f.sub.b. The information of interest is contained in an analog signal that has noise at higher frequencies. The analog signal is sampled using an integrate and hold amplifier, hence, noise from higher frequencies is aliased into the region of interest f.sub.b. In accordance with the present invention, the integrated and hold amplifier has a frequency response which has a zero at a frequency, f.sub.n, which is one of the frequencies aliased into the band of frequencies f.sub.b. Thus, the effect of the noise that appears near the frequency f.sub.n has much less effect on the signal when it is aliased into the frequency band of interest, f.sub.b. The performance of the system is thereby improved.

Abstract: A combined RFI filter and low pass filter includes two sections, both of which serve as both radio frequency interference filters and low pass filters, or dc integrators. Both sections have substantially equal time constants and employ non-polarized capacitors.

Abstract: A biquadrature switched capacitor filter having differential input/output integrator amplifiers (12,34) and switched capacitor networks (16,28,36,40). The differential outputs of one amplifier (12) are crossed and connected to the switched capacitor networks (36,40) of the other amplifier (34) to provide a negative capacitance effect. Feedforward capacitors (70,72) are switched to prevent the stage input signals (IN+, IN-) from being coupled during certain phases of a biphase nonoverlapping clock. In high-pass applications, a feedback capacitor (134, 136) makes positioning of pole and zero responses easy. Amplifier bandwidth is controlled by switched capacitors (148, 152) connected to the amplifiers during certain clock phases.

Abstract: An antipilferage system is provided with an improved signal processing system to prevent false alarms. This signal processing involves singly or in combination the improvements of a slew rate limited amplifier, which prevents impulse noise from ringing or being stretched by subsequent filters; a gain-controlled amplifier ahead of said slew rate limited amplifier, the gain of the gain-controlled amplifier being reduced as the noise and/or signal exceeds a minimum threshold level; a video detector which controls the gain-controlled amplifier and serves to maintain a minimum signal to noise ratio; a digital smoothing circuit which averages several "frames" of the entire signal such that random noise is averaged to zero while any signals which are synchronized with the modulation are added together; signal processing circuitry for the recognition of incoming signal pulse shape as compared to a predetermined pulse shape, the output of which is a trigger signal to an alarm.

Abstract: There is disclosed herein an apparatus and method for generating a first signal related to the rate of change of a second signal. In particular, a system is disclosed for generating a velocity signal in a sampled data servo system. The apparatus uses three track and hold amplifiers one of which is also a difference amplifier to sample the position error signal at selected times. A "present" track and hold amplifier samples and holds the position error signal during the current frame. After this is done, during the same frame, a "summing" track and hold amplifier having its difference inputs coupled to the outputs of the "present" track and hold amplifier and to a "previous" track and hold amplifier samples the difference between the present position error signal and the value of the position error signal during the previous sample frame. This difference divided by the sample period gives the velocity.

Abstract: A switched capacitor filter having the same value of capacitance for the integrating capacitor of each filter channel. The use of the same value capacitance results in DC offset voltages for each channel being identical and easy to correct. An input voltage divider network having a separate output tap for each channel causes each channel to have a unique filter transfer function despite the equal value of all integrating capacitors.

Abstract: A passive integrator capable of correctly providing outputs with risetimes as short as 250 ps. An outer conductor has coaxially mounted therein a short length of an inner conductor so as to constitute a very low impedance transmission line. The short length and low impedance of this transmission line cause it to behave as a capacitor. Electrostatically shielded resistors are connected to both ends thereof by a center conductor. Compensating capacitors coaxially mounted therewith may be employed.

Abstract: The symmetrical integrator comprises an operational amplifier having two floating inputs and two floating outputs each having a feedback connection to an input via a capacitor. An input capacitor is connected via two MOS transistors to two differential inputs of the integrator or via two additional MOS transistors to the inputs of the operational amplifier. The transfer function of the circuit is a pure integral or a sum of integrals if several input signals are applied to similar pairs of inputs. The integrator permits realization of filters whose transfer function has transmission zeros by utilizing additional inputs together with a direct capacitive coupling.

Abstract: A switched capacitor integrator is comprised of an operational amplifier, a feedback capacitor connected between the inverting input terminal and the output terminal of the amplifier, a bias circuit for applying a given voltage to the non-inverting input terminal of the amplifier, a switched capacitor, and a switch circuit which connects the switched capacitor between the signal input terminal applied with an input voltage signal and the inverting input terminal of the amplifier in a first operation mode and short-circuits the switched capacitor in a second operation mode.

Abstract: An electronic image framing circuit is described for eliminating the visible effects of pincushion distortion at the edges of a television image. Toward this end, portions of video lines which extend beyond a selected straight line image boundary are blanked by a pulse processor. The pulse processor responds to conventional horizontal rate and vertical rate pulses for developing blanking pulses whose widths are varied at a vertical rate. The modified blanking pulses are applied to a conventional blanking circuit for blanking the portions of video lines which extend beyond the desired image area. A parabola generator is also described for use in developing the modified blanking pulses.

Abstract: Methods and apparatus for recording pulse signal information utilizing threshold integrating devices in which a pulse shaped signal is applied to a plurality of threshold integrating devices each having a predetermined quantity of electric charge carriers stored therein, in which the threshold integrating devices are responsive to application of electric potentials above a predetermined threshold potential value for altering the amount of charge stored in the charge storage zone of the threshold integrating devices. By providing a plurality of threshold integrating devices each having a different threshold potential, significant signal information may be obtained by passive application of the pulsed signal to a plurality of the devices. This signal information may be obtained by determining the amount of charge in the charge storage zones of the respective threshold integrating devices subsequent to application of the pulsed signal thereto.

Abstract: There is shown and described a relatively simple electronic circuit using few discrete components which is used to replace the filter and delay line differentiator in existing circuits. The new circuit provides a simultaneous output of even and odd signals which have the same transfer function except for the derivative operation. The circuit is especially useful in read and write channels of a disk drive apparatus.

Abstract: Many signal processing applications of practical importance (for example, continuous-signal filtering) require high-precision temperature-insensitive transconductance elements. In accordance with one feature of this invention, a reference transconductance element is included in a control loop. The element consists of a MOSFET device or a MOSFET circuit in the loop. In the loop, the transconductance of the reference element is determined solely by the value and switching period of a switched-capacitor. The transconductance of the element is in effect thereby precisely matched against the conductance of the switched-capacitor.As the temperature of the chip varies, a control voltage is generated in the loop to maintain the transconductance of the reference element constant. This same control voltage is applied to other similar elements included in circuits (for example, filters) on the chip. In that way, the transconductances of these other elements are also matched to that of the switched-capacitor.

Abstract: High-pass, low-pass and band-pass filters are obtained by combining switched-capacitance integrating networks.

Abstract: A switched-capacitor filter circuit having at least one simulated inductor and having a resonance frequency which is one-sixth of the sampling frequency as pulse-controlled switches co-operatively operable for connecting a first capacitor to a pair of input terminals during a first clock phase and simultaneously connecting a second capacitor to the output of an inverting integration circuit, followed by discharge of the first capacitor to a capacitor in the integration circuit during a second clock pulse phase, followed by a third clock pulse phase during which the first capacitor is charged from the output of the integration circuit and the second capacitor is simultaneously connected to the pair of input terminals and during a fourth clock pulse phase the second capacitor discharges to the capacitor in the integration circuit.

Abstract: Apparatus for reducing the fundamental and harmonic frequencies of hum in a signal comprising means for placing a plurality of signal storage means between an input to which the signal is applied and an output in repeated sequence that is synchronous with the fundamental frequency of hum in such manner as to subtract the amount of signal stored from the signal passing between the input and output. The storage means are in a charging circuit having a time constant such that it requires a number of sequences to build the signal stored to its full amplitude.

Abstract: Switched capacitor topologies currently in use are susceptible to the deleterious effects of the parasitic capacitances associated with the switches. Topologies that are immune to these effects are disclosed. A first such embodiment comprises a first switch (22, 32), a capacitor (23, 33), and a second switch (24, 34) connected in series between one input terminal (1) and one output terminal (3) of the network. Third and fourth switches (26, 35 and 27, 36) are connected between the junctions (98, 42 and 99, 43) of the capacitor and the first and second switches, respectively, and the common junction (97, 41) of the second input and second output terminals (2, 4). A second embodiment is also disclosed.

Abstract: For use in a pulsed-laser lidar such as a laser ceilometer, there are shown several examples of signal processing means for separating desired pulses due to targets such as clouds from strong background signals due to suspended particles causing poor visibility. The several examples belong to a class of means having the property of applying, to an electrical signal pulse waveform, a time-distributed signed electrical weighting function having negligible total weight, with alternations of sign of weights separated by intervals of the order of the width of the desired pulses.

Abstract: An apparatus for cancelling an undesired signal includes a programmable filter in which differential waveforms of a desired signal are superimposed on one another to form a composite signal similar to an undesired signal, a control circuit for detecting a level of the undesired signal to control the gain of a level adjusting circuit of the programmable filter so as to have a value proportional to the undesired signal, and a subtracter for subtracting the composite signal from an input signal.

Abstract: By combining a number of integrators with periodically switching means, which are sensing an input signal during circularly successive time intervals, sampled values are available for some of the latest time intervals sampled with a sampling frequency. By switching these values in a successive manner to an analog arithmetic circuit, it is possible to obtain an output signal with useful band-pass and band-reject properties depending on the sampling period and the arithmetic operation. According to one preferred embodiment, the output signal is the mean over the latest time intervals, giving an averaging system which, contrary to RC circuits, has a strictly limited memory. According to another preferred embodiment, the output signal is the different between the outputs of two integrators.

Abstract: An interdigital electrode transducer mounted on an acoustic surface wave propagating medium having an output proportional to an Nth order derivative of the surface acoustic waves propagating in the medium. The Nth order derivative, where N is any real, positive number, is obtained by using a finite difference approximation. The transducer finger pairs are biphase coded and amplitude weighted in order to detect the proper combination of signal differences for the approximation and thereby indicate the desired derivative.