Abstract: An arrangement is described for demodulating a vestigial sideband signal component contained in an amplitude-modulated frequency signal, and preferably in a vision intermediate-frequency signal derived from a television signal.

Abstract: The invention relates to a compensation circuit for filters of a video signal receiver. To compensate a non-linear amplification of a small signal in dependence upon the control of a large signal which is superimposed on the small signal, the invention proposes to detect the control of the large signal and to vary the working point of the filter in dependence upon the control of the large signal. Since the filter amplifies the small signal differently in dependence upon the position of the working point, the non-linearity of the filter can thereby be compensated.

Abstract: An arrangement is described for demodulating a vestigial sideband signal component contained in an amplitude-modulated frequency signal, and preferably in a vision intermediate-frequency signal derived from a television signal.

Abstract: In order to improve a circuit arrangement (100) and a method of controlling at least one transistor (10, 12, 14, 18), especially of controlling the resistance value of at least one MOS transistor with vanishing DC modulation in such a way that a compensation of resistance variations without control deviation is also possible for the case where the transistor (10, 12, 14, 18) is operated with a vanishing DC voltage, i.e.

Abstract: A down-converter for processing frequency signals, preferably received, particularly digital, television signals, comprising two, preferably identical mixer stages (10a, 10b) for down-converting the signal, a local oscillator (12) controlling the mixer stages by a 90° phase shift, a complex filter (14) which couples the output signals of the mixer stages (10a, 10b) by means of a complex filtering method in such a way that the signal components outside a predetermined useful band are substantially suppressed, an adjusting device (13) for adjusting the frequency of the local oscillator (12) and a subsequent low-pass filter.

Abstract: In a stereo/two-tone demodulator for demodulating an intermnediate-frequency signal having stereo or two-tone sound signals modulated on a first and a second sound carrier, the second sound carrier having a lower amplitude than the first sound carrier, ceramic filters or bandpass filters are saved and complete integration can be achieved in that a first (1) and a second (2) linear narrow-band phase-locked loop are provided each having their own frequency selectivity, the first narrow-band phase-locked loop (1) being implemented in such a way that it locks in at the frequency of the first sound carrier, and the second narrow-band phase-locked loop (2) being implemented in such a way that it locks in at the frequency of the second sound carrier.

Abstract: In order to improve a circuit arrangement (100) and a method of controlling at least one transistor (10, 12, 14, 18), especially of controlling the resistance value of at least one MOS transistor with vanishing DC modulation in such a way that a compensation of resistance variations without control deviation is also possible for the case where the transistor (10, 12, 14, 18) is operated with a vanishing DC voltage, i.e.

Abstract: The invention relates to a compensation circuit for filters of a video signal receiver. To compensate a non-linear amplification of a small signal in dependence upon the control of a large signal which is superimposed on the small signal, the invention proposes to detect the control of the large signal and to vary the working point of the filter in dependence upon the control of tile large signal. Since the filter amplifies the small signal differently in dependence upon the position of the working point, the non-linearity of the filter can thereby be compensated.

Abstract: A down-converter for processing frequency signals, preferably received, particularly digital, television signals, comprising two, preferably identical mixer stages (10a, 10b) for down-converting the signal, a local oscillator (12) controlling the mixer stages by a 90° phase shift, a complex filter (14) which couples the output signals of the mixer stages (10a, 10b) by means of a complex filtering method in such a way that the signal components outside a predetermined useful band are substantially suppressed, an adjusting device (13) for adjusting the frequency of the local oscillator (12) and a subsequent low-pass filter.

Abstract: A circuit arrangement for demodulating an intermediate-frequency video signal, comprising a video demodulator (1) and a phase-locked loop (5) formed as a Costas loop, in which an output signal of a controllable oscillator (12) arranged in the Costas loop and the intermediate frequency video signal are coupled to the video demodulator (1), should always supply a demodulated video signal of a predetermined polarity, independent of overmodulation occurring in the intermediate-frequency video signal.

Abstract: For an optimal adjustment of the filter frequency of a signal filter, independently of external influences, process spreads and temperature fluctuations, a filter circuit for filtering at least one sound carrier in a composite video signal by at least one signal filter (24) having at least one filter frequency which is adjustable in dependence upon a control signal, is characterized in that the filter circuit (1) includes a reference filter (11) whose filter frequency is adjustable in dependence upon the control signal and which shifts the phase of a reference signal applied thereto by a defined value when tuning the filter frequency to the frequency of said reference signal, in that a phase comparator (14) is provided which receives the output signal of the reference filter (11) and the reference signal, in that the control signal is derived from the output signal of the phase comparator (14) in such a way that the reference filter (11) is tuned to the frequency of the reference signal, and in that an output

Abstract: An IF demodulator circuit with IF gain control at a variable time constant, which receives an IF carrier including synchronizing pulses, a black porch and picture information with a positively modulated picture signal, in which the IF picture signal is amplified to a nominal amplitude value by the gain control, and which includes an IF demodulator (3) which demodulates the IF picture signal and supplies a picture signal from the output, while, for a gain control which is independent of DC offsets that may occur in the picture signal, the demodulator circuit is constructed in such a way that a black level detector (8) for generating a black level signal used as a threshold value signal in conformity with the amplitude value of the black porch of the picture signal supplied by the amplitude demodulator (3) is provided, that a DC offset circuit (4) is provided, which raises the DC component of the picture signal and/or lowers the DC component of the threshold value signal in such a way that both signals are offs

Abstract: An oscillator (1) includes first frequency-determining elements (13-16) for providing a first oscillation frequency, at least second frequency-determining elements (23, 24) connectable to the first frequency-determining elements (13-16) via at least a switching diode (25, 26) for adjusting the oscillator (1) to a second oscillation frequency, the oscillator further having a supply circuit (27-44, 54) which includes at least a controllable current source (27-30), the supply circuit being coupled to the switching diode (25, 26) for optionally switching the switching diode between a conducting state and a blocked state, and having a current source (4) feeding the oscillator (1).

Abstract: Circuit arrangement for demodulating a video signal (IF signal) which is frequency-modulated on an intermediate-frequency carrier oscillation, including a first demodulation stage (a frequency or phase demodulator) for multiplicatively combining the IF signal with a carrier oscillation of a controllable oscillator and for supplying a first output signal, a second demodulation stage (a frequency or phase demodulator) for multiplicatively combining the IF signal with the carrier oscillation phase-shifted by a quarter period of the intermediate-frequency carrier oscillation, and for supplying a second output signal, a first filter stage for low-pass filtering the first output signal and for supplying a third output signal, a multiplier stage for multiplicatively combining the second output signal and the third output signal to form a fourth output signal, a superposition stage for forming a seventh output signal by additively combining a fifth output signal and a sixth output signal derived from the second outpu

Abstract: A circuit arrangement for demodulating the sound signals in a television signal is described, which circuit arrangement ensures a simple and low-cost structure, also for operation at different transmission standards.To this end, the circuit arrangement according to the invention includes an oscillation-generating stage which derives a (first) oscillation from a television signal (IF television signal) modulated on a first intermediate-frequency carrier oscillation, whose frequency corresponds to the frequency of an intermediate-frequency picture carrier oscillation in the IF television signal and encloses a phase angle of at least substantially 90.degree. with the picture carrier oscillation, a (first) mixer stage, a first input of which can receive the (first) oscillation, and a switching device for optionally applying the IF television signal or a sound signal (IF sound signal) modulated on a second intermediate-frequency carrier oscillation to a second input of the (first) mixer stage.

Abstract: Oscillator having first frequency-determining elements provided for a first oscillation frequency. In order to provide an oscillator, particularly for use in video signal processing, which can be switched and tuned to at least two oscillation frequencies, at least a second frequency-determining element is provided which can be connected to the first frequency-determining element for adjusting the oscillator to a second oscillation frequency.

Abstract: In order to minimize signal influences on the reference potential in a rail-to-rail amplifier arrangement this arrangement comprises a first differential amplifier which comprises a first and a second transistor whose emitters are coupled to a reference potential via a common first resistor, the collector of the first transistor forming the output node of the amplifier arrangement, a second differential amplifier to whose input side the input signal of the amplifier arrangement is applied, whose output side is coupled to the base of the first transistor of the first differential amplifier, and having an inverting input coupled to the output node of the amplifier arrangement, a first current mirror circuit having an input transistor to which a reference current is applied, having an output transistor which is formed by the second transistor of the first differential amplifier, and having the emitter side of both transistors coupled to a reference potential, and a second current mirror circuit to whose input si