Abstract: A nonintegrating, high sensitivity, wide dynamic range receiver is described. A voltage dependent current source is connected in negative feedback with a forward voltage amplifier. The transconductance of the current source is essentially independent of frequency within the signal bandwidth frequency, and the feedback pole is the dominant pole in the loop gain. To prevent saturation by high intensity input signals the receiver is combined with a range extender circuit.

Abstract: The invented device provides automatic gain control (AGC) of incoming sigs over a large dynamic range of input levels with a constant rise time. The constant rise AGC device includes a primary AGC loop for receiving the incoming or input signal and splitting the input signal to input and output components of the primary AGC loop. The input signal to the input component is processed within the primary AGC loop to control the gain of the input signal at the output component of the primary AGC loop. The primary AGC loop has a slow detector. A secondary AGC loop is provided within the primary AGC loop, and this secondary AGC loop includes the aforementioned input component and has its output connected to the slow detector. The secondary AGC loop has a fast detector for preventing self-imposed saturation.

Abstract: Broadband control amplifier having a wide control range and comprising a differential amplifier in the negative feedback loop. An auxiliary coupling is provided in the feedback loop having a transfer factor which renders the open loop gain independent of the signal distribution in the differential amplifier. The control amplifier can, for example, be used as an input amplifier in a receiver for optical fibre systems, to compensate for the length and temperature-dependent attenuation of the optical link.

Abstract: A planar varactor tuned microstrip oscillator for Ka band operation comprising a GaAs Gunn diode, a varactor diode, an impedance inverter microstrip line placing the varactor in shunt with the Gunn diode, an impedance matching transformer connected from the output of the Gunn diode to a load connection means, a source of negative bias potential for the varactor and a source of positive bias potential for the Gunn diode.

Abstract: An integratable amplifier circuit is provided including a current generator section, a digital control section and a variable gain amplifier section. The integratable amplifier circuit is compatible with the bipolar process and can be included on an integrated circuit, such as one performing receiver and audio functions. The current generator section produces a biasing current which is applied to a digital control section which divides the biasing current according to a binary input signal to produce a control current equal to a predetermined fraction of the biasing current, corresponding to a predetermined logarithmic attenuation. The control current is applied to a control input of the variable gain amplifier section to vary the gain thereof in logarithmic steps.

Abstract: A semiconductor integrated circuit comprises a differential pair of transistors, a pair of constant current source transistors, an emitter resistor connected between the emitters of the differential transistors, and a load resistor coupled to the collector of one of the differential transistors. Each of the differential transistors and constant current source transistors is a vertical PNP transistor. In the semiconductor integrated circuit, therefore, each vertical PNP transistor has its collector coupled with a parasitic diode having a relatively large junction capacitance. The parasitic diodes are reversely biased when the circuit is operative.

Abstract: A circuit arrangement including first and second output transistors, a sensor diode means, and a circuit means. The first output transistor drives the load positive. The second output transistor drives the load negative. The sensor diode means senses the current in the collector of the first output transistor. The circuit means is connected in circuit with the sensor diode means and the base of the second output transistor for establishing the quiescent current level of the first output transistor. An output of the circuit means is applied at the base of the second output transistor for preventing the output of the first output transistor from falling substantially below its quiescent current level. The output of the circuit means is dependent upon the current sensed by the sensor diode means.

Abstract: A signal amplifier device providing output power independent of change in output characteristics or common mode interference including a signal input source to provide an input signal, a first power supply and second power supply having a transformer with a secondary coil and a reference power, first differential amplifier powered by the first power supply to receive the input signal and provide first and second complementary output signals, first and second output amplifiers driven by the reference power supply and each having an input to receive one of the first and second signals and amplify same to provide first and second output signals at the respective outputs so that upon imposition of a transient signal at the output of one of the first and second output amplifiers an isolation network prevent the transient signal from appearing as a differential signal on either output.

Abstract: In a circuit arrangement comprising an amplifier and an electronic selector switch at the input of the amplifier it is possible to switch the input to one out of a plurality of incoming transmission paths. The operating current for the electronic selector switch is taken from the output of the amplifier through a negative feedback resistor.

Abstract: A constant amplitude, variable-bandwidth filter is provided having a variable resistor and a high-Q passive filter cascaded between a pair of amplifiers. The input amplifier having a low output impedance and the output amplifier having a low input impedance. As the resistance of the variable resistor is varied, the Q of the system varies and thus its bandwidth. The gain of the system also varies as the variable resistor is varied. To compensate for the gain variation, a current, equivalent to the value of the output voltage of the input amplifier divided by the value of the equivalent series resistance of the high-Q passive filter, is inserted at the node where the variable resistor and the high-Q passive filter are coupled one to the other. This results in a constant current at resonance being conducted by the high-Q passive filter, independent of the selected overall bandwidth of the filter.

Abstract: A variable frequency oscillator circuit adapted for stabilization of its free-running frequency comprises a first signal synthesizing circuit, first voltage-controlled oscillator, a phase-locked loop and reference signal generator, the phase-locked loop consisting of a second signal synthesizing circuit, second voltage-controlled oscillator, phase comparator and low-pass filter. The first and second signal synthesizing circuits have the same characteristics, and the first and second voltage-controlled oscillators have the same characteristics. The reference signal and output of the second voltage-controlled oscillator are input to the phase comparator. The comparator output is applied to the first and second signal synthesizing circuits. An external signal is applied to the first signal synthesizing circuit, and the output of the first voltage-controlled oscillator acts as the output of the variable frequency oscillator circuit.The principles are applied to reading data pulses from a floppy disk.

Abstract: In amplifier circuit arrangements for low-distortion transmission of audio signals a transformer is provided in order to isolate a source circuit from an amplifier of the amplifier circuit arrangement. Good transmission characteristics, however, can only be obtained in such circuit arrangements by using transformers of comparatively great dimensions. In order to achieve improved transmission characteristics and yet design the transformer in such a manner as to have small size, to be of low weight and inexpensive, the amplifier of the amplifier circuit arrangement is provided with a negative feedback circuit. This negative feedback circuit is connected to the source circuit by using a transformer connected in series with the current-voltage source of such source circuit.

Abstract: An amplifier circuit with high input impedance and low output impedance intended for being supplied with current via the output signal line includes a pre-amplifier with a transistor of the field-effect type (Q12) and a bipolar transistor (Q13) directly connected thereto, where the base-emitter circuit of the bipolar transistor and the source-drain circuit of the field-effect transistor (Q12) are connected in series across the supply source. The gate of the field-effect transistor is connected to a biasing source (16), the temperature coefficient of which has substantially the same absolute value as the temperature coefficient of the base-emitter voltage in the bipolar transistor (Q13), but with reverse sign.

Abstract: A programmable oscillator includes first and second transistors having their emitters coupled by a capacitor, and a pair of current sources coupling respective transistors to ground. A switching means is provided having a first state coupling the collector of the first transistor to the base of the second transistor and coupling the collector of the second transistor to the base of the first transistor, and a second state coupling the collectors of the first and second transistors to ground such that when the switching means is in the first state, the first and second transistors switch on and off in alternating fashion, and when the switching means is in the second state the first and second transistors remain on continuously.

Abstract: An integrated amplifier circuit for monolithic fabrication is disclosed. circuit includes a plurality of amplifier stages between an input transmission line and an output transmission line. Each stage includes a FET formed on the surface of a semi-insulating substrate such as gallium arsenide (GaAs). The gate of each FET is connected to the input transmission line, while the drain is connected to the output transmission line. The source is connected through the semi-insulating substrate to a conductive layer. A received signal propagates as a traveling wave along the input transmission line, and is amplified by each of the FETs. The phase delay between the gates is the same as that between the drains, so that the amplified signal adds constructively on the output transmission line. Each of the transmission lines is terminated in its own characteristic impedance, which may be equal to the load.

Abstract: An automatic gain control circuit in which a current source is provided for charging a capacitor and a current source is provided for discharging it, there being means for controlling the ratio of the currents supplied by each source in response to the amplitude of the alternating wave being controlled.

Abstract: An amplifier circuit using MOS transistors. The load to be connected to an amplifying element of the amplifier circuit is formed by a C-MOS transistor having a P-MOS transistor and an N-MOS transistor.

Abstract: A feedback-controlled current pump is coupled to the loop filter capacitor of a phase lock loop to provide a coarse prepositioning voltage and thereby accelerate the lockup process on a new frequency. Two voltage comparators monitor the capacitor voltage with respect to a selectable "window" centered about the desired voltage, and when the capacitor has been charged or discharged to a voltage within the window, the current pump providing the charging or discharging current to the capacitor is shut off.

Abstract: An improved voltage controlled amplifier employing an operational transconductance amplifier which is temperature independent and offering an improved dynamic range for the input signal is disclosed. An operational amplifier configured in the inverting mode is used as an input device having a first operational transconductance amplifier in the feedback path as a gain control element. The output of the operational amplifier provides a control voltage to effectively drive a second operational transconductance amplifier.

Abstract: The present invention relates to a method for automatically regulating the HF output power of a high frequency amplifier wherein a regulating voltage is utilized to produce a control voltage or a control current for controlling the gain of the amplifier, a first voltage which depends on the HF output power is derived from the supply voltage and/or from the supply current of the current supply device providing the power required to generate the HF power; the regulating voltage is formed of two components, with the first component being generated from the first voltage and a first reference voltage, and with the second component being generated from a second voltage which depends on the control voltage or on the control current generated by the control voltage and from a second reference voltage; and that for high HF power essentially only the first regulating component is active and for low and medium power, whose range approximately covers the linear operating range of the amplifier, essentially only the seco