Dual frequency band wireless LAN

• US 7,865,150 B2
• Filed: 06/26/2007
• Issued: 01/04/2011
• Est. Priority Date: 05/03/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Atheros Communications Incorporated (Qualcomm, Inc.)
• Inventors: Shor, Arie, McFarland, William J., Onodera, Keith K., Terrovitis, Manolis, Zaragari, Masoud, Su, David K., Thomson, John S.
• Primary Examiner(s): Addy; Anthony S.
• Application Number:
  US11/768,783
• Publication Number:
  US 20070280185A1
• Time in Patent Office: 1,288 Days
• Field of Search: 455/73, 455/76, 455/78, 455/83, 455/84, 455/86, 455/101, 455/127.2, 455/127.4, 455/133, 455/137, 455/255, 455/260, 455/264, 455/266, 455/272, 455/273, 455/324, 455/340, 455/552.1, 455/553.1, 455/103, 455/188.1, 370276-278, 370/338, 375/219, 375/267, 375/295, 375/316
• US Class Current: 455/78
• CPC Class Codes: H03H 7/0153 Electrical filters; Controlling thereof
• CPC Class Codes: H03H 7/48 Networks for connecting several sources or loads, working on the same frequency or frequency band, to a common load or source phase shifters providing two or more output signals H03H7/21
• CPC Class Codes: H04B 7/0602 using antenna switching H04B7/0686 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04B 7/0805 with single receiver and antenna switching H04B7/0822 takes precedence
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A dual band radio is constructed using a primary and secondary transceiver. The primary transceiver is a complete radio that is operational in a stand alone configuration. The secondary transceiver is a not a complete radio and is configured to re-use components such as fine gain control and fine frequency stepping of the primary transceiver to produce operational frequencies of the secondary transceiver. The primary transceiver acts like an intermediate frequency device for the secondary transceiver. Switches are utilized to divert signals to/from the primary transceiver from/to the secondary transceiver. The switches are also configured to act as gain control devices. Antennas are selected using either wideband or narrowband antenna switches that are configured as a diode bridge having high impedance at operational frequencies on control lines that bias the diodes.

Claims

1. A method of performing wireless LAN (WLAN) communications with a dual band WLAN device, the method comprising:

listening for primary communication signals in a primary frequency band;

initiating WLAN operations in the primary frequency band when the primary communication signals are detected;

listening for secondary communication signals in a secondary frequency band when the primary communication signals are not detected, each frequency band being defined by a standard; and

initiating WLAN operations in the secondary frequency band when the secondary communication signals are detected,

wherein initiating WLAN operations in the secondary frequency band includes;

in a first operation,

converting a first signal generated by a primary transceiver in the primary frequency band to the secondary frequency band in a secondary transceiver, the secondary transceiver using features of the primary transceiver to perform as a radio frequency device; and

transmitting the first signal in the secondary frequency band;

in a second operation,

receiving a second signal in the secondary frequency band in the secondary transceiver;

converting the second signal to the primary frequency band in the secondary transceiver; and

processing the second signal in the primary frequency band in the primary transceiver,

wherein the primary transceiver performs all fine gain and frequency adjustments for the primary and secondary transceivers.

2. The method according to claim 1, further comprising repeating listening for primary communication signals and initiating WLAN operations in the primary frequency band if no WLAN operations have been initiated or if previously established WLAN operations have ceased.

3. The method according to claim 2, wherein the repeating is performed at a predetermined interval.

4. The method according to claim 1, wherein:

the method is embodied in a set of computer instructions stored on a computer readable storage medium; and

the set of computer instructions, when loaded into a computer, cause the computer to perform steps of the method.

5. The method according to claim 4, wherein the set of computer instructions are compiled computer instructions stored as an executable program on the computer readable storage medium.

6. A method of performing wireless LAN (WLAN) communications with a dual band WLAN device, the method comprising:

listening for primary communication signals in a primary frequency band;

initiating WLAN operations in the primary frequency band when the primary communication signals are detected;

listening for secondary communication signals in a secondary frequency band when the primary communication signals are not detected, each frequency band being defined by a standard; and

initiating WLAN operations in the secondary frequency band when the secondary communication signals are detected,

wherein initiating WLAN operations in the secondary frequency band includes;

in a first operation,

converting a first signal generated by a primary transceiver in the primary frequency band to the secondary frequency band in a secondary transceiver, the secondary transceiver using features of the primary transceiver to perform as a radio frequency device; and

transmitting the first signal in the secondary frequency band;

in a second operation,

receiving a second signal in the secondary frequency band in the secondary transceiver;

directing flow of the second signal via switching that properly sizes the second signal so as not to saturate any components of the primary transceiver;

converting the second signal to the primary frequency band in the secondary transceiver; and

processing the second signal in the primary frequency band in the primary transceiver,

wherein the primary transceiver performs all fine gain and frequency adjustments for the primary and secondary transceivers.

7. The method according to claim 6, wherein the switching comprises at least one switch set to a position not directly connecting a signal path of the second signal so that leakage onto the signal path provides an attenuated signal to the signal path.

8. The method according to claim 6, further comprising repeating listening for primary communication signals and initiating WLAN operations in the primary frequency band if no WLAN operations have been initiated or if previously established WLAN operations have ceased.

9. The method according to claim 8, wherein repeated steps are performed at a predetermined interval.

10. The method according to claim 6, wherein:

the method is embodied in a set of computer instructions stored on a computer readable storage medium; and

the set of computer instructions, when loaded into a computer, cause the computer to perform steps of the method.

11. The method according to claim 10, wherein the set of computer instructions are compiled computer instructions stored as an executable program on the computer readable storage medium.