Power saving device for radio communication terminal

• US 6,397,090 B1
• Filed: 12/16/1998
• Issued: 05/28/2002
• Est. Priority Date: 12/16/1997
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Cho, Byung-Duck
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): West, Lewis G.
• Application Number:
  US09/212,870
• Time in Patent Office: 1,259 Days
• Field of Search: 455/67.1,67.3,69,115,127,343,423,571,572,574
• US Class Current: 455/574
• CPC Class Codes: H03F 2203/7236 the gated amplifier being switched on or off by putting into parallel or not, by choosing between amplifiers by (a ) switch(es)
• CPC Class Codes: H03F 2203/7239 the gated amplifier being switched on or off by putting into parallel or not, by choosing between amplifiers and shunting lines by one or more switch(es)
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

A power saving device for a radio communication terminal reduces current consumption by changing the number of power amplifying stages. A power amplifier in the radio communication terminal includes a first amplifier for high power and a second amplifier for low power. A signal path selector switches an input signal to an input node of the first or second amplifier in response to a switching control signal. An output path selector selects one of output signals from the first and second amplifiers in response to the switching control signal. An RSSI detector detects signal strength of a signal received from a base station. A controller generates the switching control signal of a first state, when the signal strength is low, to enable the signal path selector to switch the input signal to the first amplifier and enable the output path selector to select the output signal of the first amplifier, and generates the switching control signal of a second state, when the signal strength is high, to enable the signal path selector to switch the input signal to the second amplifier and enable the output path selector to select the output signal of the second amplifier. A power supply blocks a first supply voltage to the first amplifier in response to the switching control signal of the second state, and blocks a second supply voltage to the second amplifier in response to the switching control signal of the first state.

Claims

1. A power saving device for a radio communication terminal including a multi-stage power amplifier and an RSSI (Received Signal Strength Indicator) detector, comprising:

a controller for generating a switching control signal according to an RSSI value of a signal received from a base station, detected by the RSSI detector;

an output path selector for selecting one of output signals from first and second amplifiers in response to the switching control signal;

a signal path selector connected between the first and second amplifiers, for selectively connecting an output of the first amplifier to the second amplifier or to the output path selector, in response to the switching control signal; and

a power supply for blocking a high supply voltage to the second amplifier when the output of the first amplifier is connected to the output path selector, in response to the switching control signal, wherein the first and second amplifiers are provided with different variable voltages, said voltages being independently variable from each other.

2. A power saving device for a radio communication terminal having a first amplifier for high power and a second amplifier for low power, comprising:

a signal path selector for switching an input signal to an input node of the first or second amplifier in response to a switching control signal;

an output path selector for selecting an output signal from the first and second amplifiers in response to the switching control signal;

an RSSI detector for detecting the signal strength of a signal received from a base station;

a controller for analyzing the detected signal strength, generating the switching control signal of a first state to enable the signal path selector to switch the input signal to the first amplifier and enable the output path selector to select the output signal of the first amplifier, and generating the switching control signal of a second state to enable the signal path selector to switch the input signal to the second amplifier and enable the output path selector to select the output signal of the second amplifier; and

a power supply for blocking a first supply voltage to the first amplifier in response to the switching control signal of the second state, and blocking a second supply voltage to the second amplifier in response to the switching control signal of the first state, wherein the first and second amplifiers are provided with different variable voltages, said voltages being independently variable from each other.

3. The power saving device as claimed in claim 2, wherein the first amplifier has a gain higher than that of the second amplifier.

4. The power saving device as claimed in claim 3, wherein the signal path selector is a power splitter.

5. The power saving device as claimed in claim 2, wherein the signal path selector comprises a switch having a common node connected to the input signal, a first contact node connected to an input of the first amplifier and a second contact node connected to an input of the second amplifier.

6. The power saving device as claimed in claim 2, wherein the first and second amplifiers are provided with a level control signal.

7. The power saving device as claimed in claim 2, wherein the switching control signal of the first state is generated when the received signal strength is less than or equal to a predetermined level.

8. The power saving device as claimed in claim 2, wherein the switching control signal of the second state is generated when the received signal strength is higher than a predetermined level.

9. The power saving device as claimed in claim 7, wherein the predetermined level is 17 dBm.

10. The power saving device as claimed in claim 7, wherein the predetermined level is 13 dBm.

11. The power saving device as claimed in claim 8, wherein the predetermined level is 17 dBm.

12. A method for saving power in a radio communication terminal having a multi-stage power amplifier and an RSSI (Received Signal Strength Indicator) detector, comprising the steps of:

determining the signal strength of a received signal from a base station;

generating a switching control signal in response to the detected signal strength;

selecting an input path and an output path for the received signal in response to the generated switching control signal; and

blocking other supply voltages except for a selected supply voltage to one of the stages of the multi-stage amplifier in response to the switching control signal, wherein each stage of the multi-stage amplifier is provided with different variable voltages, said voltages being independently variable from each other.

13. The method as claimed in claim 12, wherein said step of generating further comprises the steps of:

generating a switching control signal of a first state when the determined strength of the received signal is equal to or less than a predetermined value; and

generating a switching control signal of a second state when the determined strength of the received signal is greater than the predetermined value.

14. The method as claimed in claim 13, wherein said predetermined value is 13 dBm.

15. The method as claimed in claim 13, wherein said predetermined value is 17 dBm.