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:
Sep. 27, 2005
Filed:
May. 23, 2002
Jeffrey a Dykstra, Palatine, IL (US);
Nebil Tanzi, Hoffman Estates, IL (US);
Jeffrey A Dykstra, Palatine, IL (US);
Nebil Tanzi, Hoffman Estates, IL (US);
Freescale Semiconductor, Inc., Austin, TX (US);
Abstract
A doubly balanced transceiver system having a transmit terminal (TX), a receive terminal (RX), and an an antenna terminal (ANTENNA), 180° hybrids (), 90° hybrids (and), a power amplifier () and a RX/TX switch () for disabling the power amplifier so that signals received at the transmitter are reflected to the receive terminal (RX). The 180° hybrids () preferably split and re-combine signals into parallel paths. A loopback test mode is preferably provided by use of an antenna isolation switch () to enable a power detect terminal (POWER_DETECT). This eliminates pricey and problematic GaAs switches, and allows the use of low cost silicon for the power amplifier. The doubly balance architecture also has the advantage of eliminating common-mode noise, and reflection problems with the PA gain stages. Additionally, greater power can be extracted from the power amplifier. Further the arrangement has less insertion loss compared to a GaAs switch. Also, dependant upon system specifications, it may be possible to eliminate harmonic filtering at the power amplifier output.