Personal communication device with transmitted RF power strength indicator

• US 7,088,999 B2
• Filed: 12/04/2003
• Issued: 08/08/2006
• Est. Priority Date: 08/20/2002
• Status: Active Grant

• Current Assignee: VIA Technologies Incorporated (VIA Technologies)
• Original Assignee: VIA Technologies Incorporated (VIA Technologies)
• Inventors: Ho, Bing-Ming, Chen, Chun-Chieh, Shih, Did-Min
• Primary Examiner(s): NGUYEN, DUC MINH
• Application Number:
  US10/726,510
• Publication Number:
  US 20040121795A1
• Time in Patent Office: 978 Days
• Field of Search: 455423-425, 455522-523, 455/67.11, 455/67.14, 455/67.16, 455/67.7, 4551151-1154, 4552261-2264
• US Class Current: 455/423
• 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
• CPC Class Codes: H04B 2001/3844 with means to alert the user that a certain exposure has been reached
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

A radio communication system for communication between a first mobile system and a second mobile system. Each mobile system has a transceiver for receiving and emitting radio signal. The second mobile system comprises a received signal strength detecting device, a power controller and an indicating device. The received signal strength detecting device detects a received signal strength of the transceiver in the second mobile system. The power controller outputs a transmitted power strength status and controls transmitted power of the transceiver according to the received signal strength. The indicating device receives the transmitted power strength status and indicates a transmitted RF power strength status of the transceiver in the second mobile.

Claims

1. A radio communication system for communication between a first mobile system and a second mobile system, each of the first and the second mobile systems having a transceiver for receiving and emitting radio signals, the second mobile system comprising:

a received signal strength detecting device for detecting a received signal strength of the transceiver in the second mobile system, wherein the received signal strength is represented as voltage;

a power controller for outputting a transmitted power strength status comprising;

a V-I converter which is a transistor array comprising P-type MOS transistors, wherein the gates of the P-type MOS transistors are controlled by the received signal strength, the V-I converter generates a supply current to power a transmitter of the transceiver in the second mobile system corresponding to the received signal strength to control a transmitted power of the transceiver in the second mobile system;

a transmitted power calibration device with switches, wherein each switch is connected in series with a corresponding P-type MOS transistor in the V-I converter to decide whether current is allowed to flow through the corresponding P-type MOS transistor; and

an indicating device for receiving the transmitted power strength status and indicating a transmitted RF power strength status of the transceiver in the second mobile system.

2. The radio communication system as claimed in claim 1, wherein the power controller comprises a transmitted power calibration device connected in series with the V-I converter to calibrate the supply current for controlling the transmitted power of the second mobile.

3. The radio communication system as claimed in claim 1, wherein the power controller further has a current measurer to measure the supply current and to correspondingly generate the transmitted power strength status.

4. The radio communication system as claimed in claim 3, wherein the current measurer is an analog to digital converter.

5. A method for indicating a transmitted signal power level of a Personal Communication Device (PCD), the method comprising the following steps:

detecting a received signal strength of a received signal of the PCD;

converting the received signal strength into a supply current to control a transmitter of the PCD;

calibrating the supply current to modify the transmitted power of the transmitter, wherein the supply current is determined by a plurality of switches, selectively turned-on or turned-off;

determining a transmitted power strength of the transmitter; and

indicating the transmitted power strength via an indicating device in the PCD, whereby an user of the PCD is alerted to RF radiation of the PCD.

6. The method as claimed in claim 5, wherein the received signal strength is represented as voltage and the step of converting the received signal strength into the supply current is performing a V-I conversion.

7. The method as claimed in claim 5, wherein the step of determining the transmitted power strength of the transmitter is performed by detecting the supply current.