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. 10, 1995
Filed:
Oct. 06, 1994
Michael McGinn, Tempe, AZ (US);
W Eric Main, Mesa, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A demodulation circuit (10) performs quadrature demodulation on an IF input signal. The IF input signal processes through a preamplifier (12) to one input of a mixer (14). The mixer output goes to first and second multipliers (20, 22). A VCO (24) generates an oscillator signal that processes through a first multiplier (26) and first and second dividers (28, 30) to generate in-phase and quadrature recovered carrier signals that are applied to second inputs of the first and second multipliers which in turn produce the in-phase and quadrature demodulated baseband signals. A switching arrangement (32, 38, 40) for the multiplier and dividers provides the proper frequency signal to a second input of the mixer to generate sum and difference frequencies. A filter and amplifier at the output of the mixer removes the summation frequency leaving the difference frequency to the first and second multipliers.