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:
Apr. 05, 1988
Filed:
Oct. 15, 1986
Applicant:
Inventors:
Charles R Ward, Wayne, NJ (US);
Ning H Lu, Parsippany, NJ (US);
Assignee:
ITT Avionics, a division of ITT Corporation, Nutley, NJ (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
375 75 ; 375 39 ; 455315 ; 455324 ;
Abstract
There is described a zero IF receiver which affords to reduce offsets normally associated with quadrature mixers employed in such receivers. In order to reduce the effect of such offsets the local oscillator signal is modulated with a balanced pseudo-random phase code signal. This signal is then stripped off by means of additional mixers, one for each of the quadrature channels. The effect of the pseudo-random phase code signal is to spread the spectrum which is associated with the offsets so that the receiver can now respond to desired signals with a minimum of interference.