Abstract: There is provided a method that comprises identifying a parasitic signal transfer in a filter using a signal-directed graph; and adding compensation paths to the filter to reduce or eliminate the effect of the parasitic signal transfer A corresponding filter is provided which comprises a plurality of amplifier stages that generate one or more filter poles; at least one component coupled to at least one of the amplifier stages, the component causing a parasitic effect in the filter; and means for applying a compensation current to the at least one amplifier stage to reduce or eliminate the parasitic effect.

Abstract: There is provided an amplifier that comprises a plurality of amplifier stages arranged in a cascade; and a frequency-dependent load associated with the output of at least one of the plurality of amplifier stages, the frequency dependent load being adapted to reduce a voltage or current offset in the output of said at least one amplifier stage.

Abstract: There is provided a method that comprises identifying a parasitic signal transfer in a filter using a signal-directed graph; and adding compensation paths to the filter to reduce or eliminate the effect of the parasitic signal transfer A corresponding filter is provided which comprises a plurality of amplifier stages that generate one or more filter poles; at least one component coupled to at least one of the amplifier stages, the component causing a parasitic effect in the filter; and means for applying a compensation current to the at least one amplifier stage to reduce or eliminate the parasitic effect.

Abstract: Voltage controlled oscillator provided with a resonant network, an amplifier and a reactive network, all incorporated in an oscillator loop, the reactive network having one or more reactive components whose values depend on a control signal fed to a control input, so that the oscillator frequency can be regulated with said control signal. A control loop is provided between the resonant network and the reactive network, with which control loop the difference is determined between a measure of the imaginary part of the impedance or admittance of the resonant network and the control signal acting as reference quantity. The imaginary part of the impedance or admittance of the reactive network is regulated with said difference. The control loop contains a derivation circuit for deriving said measure and a differential amplifier, to one input of which the output signal of the derivation circuit is fed and to the other input of which the control signal is fed.

Abstract: Inductive proximity sensor for detecting an object having electrical conductivity comprising a sensor housing, a measuring coil and reference coil placed on either side of a plane of symmetry through the sensor housing. Each coil is partly surrounded by a piece of magnetic material which leaves the measuring coil or reference coil respectively free at the front which faces the direction of the object to be detected or a reference member. An electronic circuit is provided for supplying both coils with an AC signal and for measuring the change in a specific property of the measuring coil with respect to that of the reference coil when object approaches and determining therefrom the distance or the presence of the object. The pieces of magnetic material around the two coils are formed essentially from the same homogeneous material forming a block. Means are provided in the sensor housing for screening magnetic fields produced by both coils in order to suppress thereby mutual crosstalk.

Abstract: Voltage-controlled oscillator provided with a frequency-determining element and an oscillator loop having a phase-rotating network, in which the value of one or more elements depends on a control signal which is fed to a control input and with which the phase rotation and thereby the oscillator frequency can be changed. The oscillator is further provided with a phase control loop, at least comprising a phase-rotating network to the input of which the oscillator signal is fed, a phase detector to the two inputs of which the input signal and the output signal of said phase-rotating network are fed, and an amplifier which amplifies the output signal of the phase detector and feeds it to the control input of the phase-rotating network of the oscillator loop. The phase detector has an accurately known and temperature-independent input-output relation. The phase-rotating network of the phase control loop may be formed by the phase-rotating network of the oscillator loop (FIG. 2).

Abstract: AM receiver comprising a tuning oscillator (T0), a first phase detector (PD1) and a first loop filter (LP1) successively arranged in a first phase control loop. The tuning oscillator (T0) is synchronized with a reference oscillator (VCX0) coupled to the first phase detector (PD1) and applies a mixing frequency to a mixer stage (M) for conversion of a received AM signal into an IF-AM signal. The mixer stage (M) is coupled to an AM demodulator (SD) for demodulation of the base-band modulation signal. The reference oscillator (VCX0) is controllable and is disposed between a second loop filter (LP2) and a second phase detector (PD2) of a second phase control loop coupled to the mixer stage (M) for applying a local detection carrier synchronized with the IF-AM signal carrier to the AM demodulator (SD).

Abstract: Gain-controlled amplifier arrangement with a cascade arrangement of first and second gain-controlled amplifier stages, an AM-detection circuit and an integrating arrangement for generating a control voltage for the two stages and a threshold circuit for generating first and second threshold voltages, for delaying at an increasing input level the start of the control of the first stage (1-8) relative to that of the second stage (19-28). So as to prevent the gain control of the first stage from starting, for example because of an unwanted variation of the threshold voltages, before the gain control of the second stage has ended, the control ranges of the two stages are separated from each other by a separation area in which no gain control is effected.