The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 25, 1984
Filed:
Dec. 17, 1979
Robert Maurer, D-6600 Saarbrucken, DE;
Michael Hoffmann, D-6600 Saarbrucken, DE;
Other;
Abstract
A demodulator circuit for demodulating an input signal constituted by a modulated carrier. The circuit is provided with a phase control loop composed of a signal mixer having two inputs and an output and providing a signal at its output proportional to the algebraic product of the signals at its inputs, one of the mixer inputs being arranged to receive the demodulator circuit input signal, a voltage controlled oscillator having a control input and an output connected to the other input of the mixer and providing a signal at a frequency varying linearly with the voltage at its control input, and a lowpass filter connected between the mixer output and the oscillator control input. The components of the loop present a set of parameters defining the operation of the loop, which parameters include the peak voltage at the output of the oscillator, the oscillator modulation sensitivity, the voltage amplification factor of the lowpass filter and the gain of the mixer. Circuit devices are connected to the loop for varying at least one of the parameters in inverse proportion to the peak amplitude of the input signal carrier for causing the product of the parameters and the carrier peak amplitude to be substantially constant.