Antenna selection circuit for use in mobile computers

• US 20030050033A1
• Filed: 01/03/2002
• Published: 03/13/2003
• Est. Priority Date: 09/13/2001
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Kawaguchi, Dean
• Granted Patent: US 6,873,835 B2
• Time in Patent Office: Days
• US Class Current: 455/277.1
• CPC Class Codes: H04B 7/082 selecting best antenna path

Abstract

A method of selecting between first and second antennas in a quadrature amplitude modulation receiver having in-phase (I) and quadrature (Q) signal channels for demodulating signals received by the antennas, comprising the steps of imultaneously connecting the first antenna to the I channel to obtain a first output signal having a first amplitude, and the second antenna to the Q channel to obtain a second output signal having a second amplitude; measuring the first and second amplitude to obtain a greater amplitude for one on the antennas; and switching to said of the antennas having the greater amplitude for demodulating the received signals.

Claims

1. A method of selecting between first and second antennas in a quadrature amplitude modulation receiver having in-phase (I) and quadrature (Q) signal channels which having substantially equal power over a predetermined time interval for demodulating signals received by the antennas, comprising the steps of:

a) simultaneously connecting the first antenna to the I channel to obtain a first output signal having a first amplitude, and the second antenna to the Q channel to obtain a second output signal having a second amplitude;

b) measuring the first and second amplitude to determine the one of the antennas having the greater amplitude; and

c) switching to said one of the antennas having the greater amplitude over a predetermined time interval for demodulating the received signals.

2. A circuit selecting between first and second antennas in a quadrature amplitude modulation receiver having in-phase (I) and quadrature (Q) signal channels for demodulating signals received by the antennas, comprising the steps of:

a) simultaneously connecting the first antenna to the I channel to obtain a first output signal having a first amplitude, and the second antenna to the Q channel to obtain a second output signal having a second amplitude;

b) measuring the first and second amplitude to obtain a greater amplitude for one on the antennas; and

c) switching to said of the antennas having the greater amplitude for demodulating the received signals.