摘要:
In a radio receiver in accordance with the heterodyne principle or with the homodyne principle, two additional transmission channels are provided for interference suppression. The two additional transmission channels have a different degree of distortion. Either mixing with a heterodyne oscillator signal takes place in each of the two transmission channels and the resultant intermediate frequency signals or baseband signals are added in phase opposition to give a sum signal, or the output signals of the two additional transmission channels are added in phase opposition to give a sum signal and the resultant sum signal is mixed with a heterodyne oscillator signal to give an intermediate frequency signal or baseband signal. The signals obtained after addition and mixing and derived from the output signals of the two additional transmission channels are frequency-selected and demodulated, and the demodulated signal is used for gain control.
摘要:
In an integrated circuit arrangement with a protective arrangement at least partially integrated into it and protecting the integrated circuit arrangement from high-energy electrical faults, the protective arrangement has an ohmic resistance in the form of one or more resistance areas that is designed so as to absorb a major proportion of the energy from electrical faults in the event of limit loads and distribute the heat generated within it by the energy absorption over a surface of the protective arrangement such that the protective arrangement affected by the heat energy of the ohmic resistance is not thermally overloaded. Furthermore, the protective arrangement has a voltage-limiting element or several voltage-limiting elements to limit the interference voltage.
摘要:
In a radio receiver in which the received signal is converted by mixing into an intermediate frequency signal and/or a baseband signal, and in which an apparatus is provided which generates an intermediate frequency signal and/or baseband signal and derives therefrom a control signal for suppression or reduction of interfering disturbances, the signal fed to the apparatus is distorted in the apparatus in such a way that the signal distortion effected in the apparatus is greater than the distortion to which the signal fed to the receiver is subjected in the receiving section of the receiver.
摘要:
In a mixer stage comprising a transistor for mixing, with the input signal and/or the oscillator signal being fed inductively to the mixing transistor, there is provided for inductively coupling the mixer transistor to the corresponding filter a coil which is magnetically coupled to this filter. The inductivity of the coupling coil is of such dimensions that the source impedance controlling the transistor to a greater than the input impedance of the mixer transistor when the filter is aligned.
摘要:
An integrated amplifier circuit comprising an amplifier transistor connected in a common base configuration with its base zone being connected via an integrated capacitance to the semiconductor substrate of the integrated circuit so as to connect (short circuit ) the base zone to the semiconductor substrate at the operating frequency of the amplifier.
摘要:
In a circuit for transforming direct-current signals whose output signal is dependent on the input signal, the temperature variation of the output signal is adjustable, and two transistors whose base-emitter sections exhibit an appropriate voltage difference are provided for control of the temperature variation of the output current.
摘要:
In a selective amplifier stage with a frequency-selective input filter to which there is coupled inductively an amplifier transistor, there is provided for the inductive coupling of the amplifier transistor to the filter a coil which is magnetically coupled to the coil of the input filter. The coupling coil is of such dimensions that when the input filter is aligned to maximum amplification of the stage, the source impedance driving the transistor is greater than the input impedance of the amplifier transistor.
摘要:
A system for regulating the transfer impedance of a plurality of current-to-voltage converters to a substantially equal value includes a reference voltage source and a reference impedance for providing a reference current. A reference current-to-voltage converter is responsive to the reference current and provides an output voltage. A comparator is responsive to the reference voltage and the output voltage and provides a control signal to the reference current-to-voltage converter and to all the other current-to-voltage converters to maintain the transfer impedance of all the current-to-voltage converters constant.
摘要:
In a controllable amplifier circuit with an amplifier transistor a further transistor is provided that, when actuated under control conditions, deprives the amplifier transistor of at least a part of the input signal.
摘要:
A signal input circuit composed of a control member, such as a PIN diode, for controllable attenuation of an input signal, and reactances for selection of the input signal, wherein the signal frequency current is regulated by the control member such that the operating power required by the input circuit remains constant to the greatest possible degree in spite of the regulation.