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:
May. 09, 2000
Filed:
Apr. 22, 1998
Applicant:
Inventor:
Peter H Saul, Towcester, GB;
Assignee:
Mitel Semiconductor Limited, , GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03B / ;
U.S. Cl.
CPC ...
327107 ; 327106 ; 327105 ; 327113 ; 708271 ;
Abstract
A frequency synthesizer comprises a direct digital frequency synthesizer (DDFS), which provides in-phase and quadrature sinewave signals at a preset frequency from digital analogue converters respectively, and a balanced mixer. The balanced mixer provides an output signal having a carrier frequency twice that provided by DDFS and reduced levels of spurious signals. A signal having a desired frequency is generated by controlling the DDFS to generate sinewave output signals at half the desired frequency. The reduced levels of spurious signals obtained by the arrangement allows improved signals for use in, for example, local oscillator applications.