Tunable dual band antenna system

• US 6,697,030 B2
• Filed: 05/13/2002
• Issued: 02/24/2004
• Est. Priority Date: 05/23/2001
• Status: Expired due to Term

• Current Assignee: NETGEAR, Inc.
• Original Assignee: Sierra Wireless Incorporated
• Inventors: Gleener, Andrey
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): CHEN, SHIH CHAO
• Application Number:
  US10/145,324
• Publication Number:
  US 20020175870A1
• Time in Patent Office: 652 Days
• Field of Search: 343/702, 343/745, 343/850, 343/860, 343/861
• US Class Current: 343/860
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 5/335 at the feed, e.g. for impedance matching
• CPC Class Codes: H01Q 9/14 Length of element or elements adjustable telescopic elements H01Q1/10
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H

Abstract

A tunable dual band antenna system is disclosed. The system includes a transceiver, a matching network and an antenna. The matching network is operable to tune the antenna to the transceiver at both a first and second frequency. Accordingly, the matching network has a variable capacitor, an inductor and a second capacitor. The value of the variable capacitor is chosen to tune the antenna at the first frequency and the second frequency such that the system can be used to transmit and receive electromagnetic energy over two bandwidths. The values of the variable capacitor, the inductor, and the second capacitor are chosen to minimize the standing wave ratio of the system at both the first frequency and the second frequency.

Claims

1. A tunable band antenna system, the system comprising:

a transceiver;

a matching circuit electrically coupled to the transceiver;

a control circuitry, coupled to the matching network, operable to dynamically vary the impedance of the matching network; and

an antenna electrically connected to the matching network;

the matching circuit dynamically matched to the impedance of the antenna and the transceiver at a first and a second frequency through operation of the control circuitry.

2. A matching circuitry for an antenna and a transceiver, the matching circuitry comprising:

an inductor in electrical communication with the antenna;

a first capacitor in electrical communication with the inductor and the antenna;

a second capacitor in electrical communication with the inductor and the transceiver, the second capacitor being to match the impedance of the transceiver to the antenna at a first frequency and a second frequency; and

a control circuitry, electrically connected to one or both of the capacitors, operative to dynamically vary the capacitance of the capacitors it is electrically connected to, such that the control circuitry operable to match the impedance between the antenna and the transceiver by varying the capacitance of the connected capacitor.

3. A method of performing efficient transmission of energy at a first frequency and a second frequency in an antenna system having a transceiver and an antenna, the method comprising the steps of:

providing a matching circuitry communicatively coupled to a control circuitry;

minimizing the standing wave ration for the system with the control circuitry and the matching circuitry at the first frequency; and

minimizing the standing wave ration for the system with the control circuitry and the matching circuitry at the second frequency.