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:
Feb. 20, 2001
Filed:
May. 12, 1999
Sek Loon Chan, Penang, MY;
Sin Hooi Cheah, Butterworth, MY;
Motorola, Inc., Schaumburg, IL (US);
Abstract
A coupling circuit (,) for a radiofrequency (RF) receiver (,) has an attenuator (,) and a resonator (,). Three resistors (,) of attenuator (,) provide a lossy resistive isolation between a first mixer (,) and a crystal filter (,) of (RF) receiver (,) for undesired signals such as noise and harmonics. Thus, signal reflections between first mixer (,) and crystal filter (,) are absorbed for these undesired signals. However, for desired signals at an intermediate frequency (IF), resonator (,) has an inductor (,) and a capacitor (,) to resonate with such desired signals at the IF. As a result of resonance, resistors (,) are isolated to alleviate attenuation of the desired signals.