Wireless terminal with reduced SAR peak value and method for reducing SAR peak value by using the wireless terminal

• US 9,331,730 B2
• Filed: 02/21/2012
• Issued: 05/03/2016
• Est. Priority Date: 10/12/2011
• Status: Active Grant

• Current Assignee: Xi'An Zhongxing New Software Co., Ltd. (ZTE Corporation)
• Original Assignee: ZTE Corporation
• Inventors: Zhang, Lu, Li, Long, Yang, Yang
• Primary Examiner(s): Rego, Dominic E
• Application Number:
  US14/350,134
• Publication Number:
  US 20150057053A1
• Time in Patent Office: 1,533 Days
• Field of Search: 455/575.5, 455/575.7, 455/129, 455/13.3, 343/751, 343/853, 343/879, 343/893
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/2275 associated to expansion card or bus, e.g. in PCMCIA, PC cards, Wireless USB
• CPC Class Codes: H01Q 1/245 with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength
• CPC Class Codes: H04B 1/3838 Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use

Abstract

A wireless terminal with a reduced Specific Absorption Rate (SAR) peak value and a method for reducing an SAR peak value by using the wireless terminal are disclosed. The wireless terminal with a reduced SAR peak value includes a first antenna configured to receive or transmit a communication signal, and further includes: a second antenna configured to feed a coupling signal when the first antenna receives or transmits the communication signal, and a signal processing module configured to process the coupling signal to reduce an SAR peak value of the communication signal for a human body. The energy of a superposed signal in a human body orientation is reduced by superposing the coupling signal with the communication signal, so as to reduce the SAR peak value effectively.

Claims

1. A wireless terminal with a reduced Specific Absorption Rate (SAR) peak value, which comprises a first antenna configured to receive or transmit a communication signal, wherein the wireless terminal further comprises:

a second antenna, configured to feed a coupling signal when the first antenna receives or transmits the communication signal; and

a signal processing module, configured to process the coupling signal to reduce an SAR peak value of the communication signal for a human body; and

a human body sensor, configured to sense and output orientation information of the human body;

wherein the signal processing module is further configured to;

receive the orientation information of the human body,

determine, according to the orientation information of the human body and an amplitude and a phase of the communication signal, the amplitude and the phase of the coupling signal corresponding to a minimum value of the energy of the near-field superposed signal in the human body orientation, and

adjust the coupling signal according to the determined amplitude and phase of the coupling signal.

2. The wireless terminal with a reduced SAR peak value according to claim 1, wherein the signal processing module is further configured to:

adjust an amplitude and a phase of the coupling signal, so as to change an amplitude ratio and a phase difference between the coupling signal and the communication signal and to reduce energy of a near-field superposed signal of the coupling signal and the communication signal.

3. The wireless terminal with a reduced SAR peak value according to claim 2, wherein the second antenna comprises:

a second feed source, configured to feed the coupling signal; and

a second radiator, configured to receive or transmit the coupling signal.

4. The wireless terminal with a reduced SAR peak value according to claim 3, wherein the second radiator is a tortuous conducting line or a conducting strip with multiple branches.

5. The wireless terminal with a reduced SAR peak value according to claim 4, wherein the human body sensor is an optical sensor, a thermal sensor, a gravity sensor or a proximity sensor, and the human body sensor includes multiple human body sensors distributed on each inner surface of the wireless terminal.

6. The wireless terminal with a reduced SAR peak value according to claim 1, wherein the second antenna is further configured to feed the communication signal, and receive or transmit the communication signal.

7. A method for reducing a Specific Absorption Rate (SAR) peak value by using a wireless terminal, comprising:

feeding a coupling signal when a communication signal is received or transmitted; and

processing the coupling signal to reduce an SAR peak value of the communication signal for a human body;

wherein the step of processing the coupling signal to reduce an SAR peak value of the communication signal for a human body comprises;

adjusting an amplitude and a phase of the coupling signal, so as to change an amplitude ratio and a phase difference between the coupling signal and the communication signal and to reduce energy of a near-field superposed signal of the coupling signal and the communication signal; and

the method further comprises;

before the amplitude and the phase of the coupling signal are adjusted,

sensing orientation information of the human body; and

determining, according to the orientation information of the human body and an amplitude and a phase of the communication signal, the amplitude and the phase of the coupling signal corresponding to a minimum value of the energy of the near-field superposed signal in the human body orientation.