Apparatus for wirelessly transmitting information, communication terminal for wirelessly transmitting information and impedance matching method

• US 9,100,109 B2
• Filed: 08/29/2011
• Issued: 08/04/2015
• Est. Priority Date: 10/04/2010
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Epcos AG (TDK Corporation)
• Inventors: Schmidhammer, Edgar, Tikka, Pasi
• Primary Examiner(s): Vuong, Quochien B
• Application Number:
  US13/877,435
• Publication Number:
  US 20130244589A1
• Time in Patent Office: 1,436 Days
• Field of Search: 455/63.1, 455/67.13, 455/73, 455/78, 455/82, 455/333, 333/17.3, 333/101, 333/109, 333/124
• US Class Current: 1/1
• CPC Class Codes: H03H 2007/386 Multiple band impedance matching
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• 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
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10

Abstract

An apparatus for wirelessly transmitting information includes a transmitting/receiving unit and an antenna unit. An electrical signal path is between the transmitting/receiving unit and the antenna unit. A front-end module contains at least one duplexer and is electrically connected into the signal path between the transmitting/receiving unit and the antenna unit. A detector unit is used for detecting signals proportional to radio-frequency signals propagating in the signal path. The detector unit is electrically coupled to the signal path between the transmitting/receiving unit and the front-end module.

Claims

1. An apparatus for wireless information transmission, the apparatus comprising:

a transmission/reception unit comprising a transmitter and a receiver;

an antenna terminal;

an electrical signal path between the transmission/reception unit and the antenna terminal;

a front end module comprising a duplexer, the front end module being electrically connected in the signal path between the transmission/reception unit and the antenna terminal and wherein the signal path between the transmitter and the front end module comprises a transmission path for sending radio-frequency signals and the signal path between the receiver and the front end module comprises a reception path for receiving radio-frequency signals;

a detector unit electrically coupled to the transmission path between the transmitter and the front end module and configured to sense signals in proportion to radio-frequency signals propagating in the signal path;

an antenna unit coupled to the antenna terminal, the antenna unit comprising an antenna;

a matching circuit that has at least one first tunable impedance element and is electrically connected in the signal path between the front end module and the antenna terminal for the purpose of impedance matching in transmission and/or reception frequency ranges; and

a control unit electrically connected to the detector unit and to the matching circuit, the control unit configured to take the signals sensed by the detector unit as a basis for altering the impedance of the matching circuit;

wherein the matching circuit comprises;

a matching circuit signal path with a signal path input and a signal path output, wherein the at least one first tunable impedance element is electrically connected in the matching signal path;

a second tunable impedance element electrically connected between the signal path input and a ground;

a first inductive element electrically connected between the signal path output and the ground;

a second inductive element electrically connected between the signal path input and the ground; and

a voltage-dependent variable resistance element electrically connected between the signal path output and the ground; and

wherein voltage-dependent variable resistance element and the second inductive element are arranged such that harmful interference signals entering the matching circuit via the antenna terminal are discharged to the ground via the second inductive element or via the voltage-dependent variable resistance element.

2. The apparatus according to claim 1, wherein the matching circuit is set up such that the matching in at least one transmission frequency range and the matching in at least one reception frequency range can be performed simultaneously.

3. The apparatus according to claim 1, wherein the front end module, the detector unit, the matching circuit and the control unit are integrated in a single module and the module is a tunable front end module.

4. The apparatus according to claim 1, wherein the detector unit comprises at least one directional coupler.

5. A communication terminal for wireless information transmission, having an apparatus according to claim 1.

6. The apparatus according to claim 1, wherein the matching circuit further comprises a third inductive element electrically connected between the signal path input and the first impedance element.