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:
Oct. 30, 1979
Filed:
Dec. 13, 1977
Wilhelm Hegeler, Hildesheim, DE;
Wolfgang Busse, Hildesheim, DE;
Blaupunkt-Werke GmbH, Hildesheim, DE;
Abstract
To provide a synthesized tuning frequency to control the local oscillator in a superheterodyne receiver, a frequency generating circuit includes a reference oscillator which provides a reference frequency which is frequency-divided to generate a plurality of divided sub-frequencies which, with respect to the reference frequency have at least a flank which is non-coincident with respect to corresponding flanks of other frequencies. These divided frequencies are added in an adder, the addition of which is controlled in accordance with a tuning command stored in a digital memory. Preferably, the adder is a NOR-gate to which selected frequencies are connected, selected by NAND-gates in accordance with a number provided by a digital tuning control and stored in the digital memory. The synthesized frequency is then used to provide an error control signal within a control loop connected to the local oscillator.