SYSTEM AND METHOD FOR ZERO INTERMEDIATE FREQUENCY FILTERING OF INFORMATION COMMUNICATED IN WIRELESS NETWORKS

• US 20110124308A1
• Filed: 01/31/2011
• Published: 05/26/2011
• Est. Priority Date: 04/07/2006
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: BelAir Networks (Telefonaktiebolaget LM Ericsson)
• Inventors: KEIR, ANDREW, RAYMENT, STEPHEN, PARSONS, KIERAN, DUBOIS, MARC
• Granted Patent: US 8,280,337 B2
• Time in Patent Office: Days
• US Class Current: 455/307
• CPC Class Codes: H04B 1/30 for homodyne or synchrodyne receivers demodulator circuits H03D1/22

Abstract

A circuit for communicating information in a wireless network includes a filtering circuit in communication with a zero intermediate frequency (ZIF) transceiver circuit. The filtering circuit includes a first mixer in communication with an output of the ZIF transceiver circuit. The filtering circuit includes a first Surface Acoustic Wave (SAW) filter circuit in communication with an output of the first mixer. The filtering circuit includes a second mixer in communication with an output of the first SAW filter circuit. The filtering circuit includes a third mixer, and a second SAW filter circuit in communication with an output of the third mixer. The filtering circuit includes a fourth mixer in communication with an output of the second SAW filter circuit and an input of the ZIF transceiver circuit. The filtering circuit also includes a local oscillator circuit in communication with the first, second, third and fourth mixers.

Claims

1. An apparatus for communicating information, comprising:

a filtering module in communication with a zero intermediate frequency (ZIF) communication circuit,

wherein the filtering module comprises;

a first mixer circuit in communication with an output of the ZIF communication circuit,

wherein the first mixer circuit is configured to down-convert a transmission signal at a first frequency from the ZIF communication circuit to a second frequency to generate a down-converted transmission signal;

a first filtering circuit in communication with an output of the first mixer circuit,

wherein the first filtering circuit is configured to filter the down-converted transmission signal to generate a filtered down-converted transmission signal;

a second mixer circuit in communication with an output of the first filtering circuit,

wherein the second mixer circuit is configured to up-convert the filtered down-converted transmission signal to a third frequency to generate a filtered transmission signal;

a third mixer circuit,

wherein the third mixer circuit is configured to receive a received signal at a fourth frequency, and

wherein the third mixer circuit is configured to down-convert the received signal to a fifth frequency to generate a down-converted received signal;

a second filtering circuit in communication with an output of the third mixer circuit,

wherein the second filtering circuit is configured to filter the down-converted received signal to generate a filtered down-converted received signal;

a fourth mixer circuit in communication with the second filtering circuit,

wherein the fourth mixer circuit is configured to up-convert the filtered down-converted received signal to a sixth frequency to generate a filtered received signal, and

wherein the ZIF communication circuit is in communication with an output of the fourth mixer circuit; and

at least one oscillator circuit in communication with the first, second, third and fourth mixer circuits,

wherein the at least one oscillator circuit is configured to control mixing frequencies of the first, second, third and fourth mixer circuits.