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. 14, 2009
Filed:
Feb. 16, 2001
Applicant:
Ranjit Gharpurey, Plano, TX (US);
Inventor:
Ranjit Gharpurey, Plano, TX (US);
Assignee:
Texas Instruments Incorporated, Dallas, TX (US);
Primary Examiner:
Int. Cl.
CPC ...
H04B 1/44 (2006.01); H04B 1/40 (2006.01);
U.S. Cl.
CPC ...
Abstract
A radio such as a frequency division duplex (FDD) radio () has a first local oscillator (LOI and LOQ) that is set to coincide with the transmitter section's () center frequency or a sub-harmonic thereof. In this way, after the first down-conversion, the transmit interferer is converted to DC, where it can be effectively removed using a simple high-pass filter () such as a DC blocking capacitor. Image rejection is achieved by the use of a two-step down-conversion approach that uses quadrature local oscillators to implement a single-sideband down-converter.