Dual antenna diversity transmitter and system with improved power amplifier efficiency

• US 20050143024A1
• Filed: 05/03/2004
• Published: 06/30/2005
• Est. Priority Date: 12/26/2003
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Hwang, Jung Hwan, Hyoung, Chang Hee, Kang, Sung Weon, Kim, Yun Tae, Sung, Jin Bong
• Granted Patent: US 7,142,829 B2
• Time in Patent Office: Days
• US Class Current: 455/101
• CPC Class Codes: H04B 7/0608 Antenna selection according to transmission parameters
• CPC Class Codes: H04B 7/0808 comparing all antennas before reception
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

Provided is a dual antenna diversity transmitter and system having improved power amplifier efficiency, and further comprising switches in the dual antenna diversity transmitter and system, to minimize a DC input power consumed by the power amplifier depending on the required transmitting output power and operate efficiently the power amplifier, whereby signal linearity can be maintained and the power amplifier can be efficiently operated in a more simplified manner, as compared to the conventional high efficiency power amplifier.

Claims

1. A dual antenna diversity transmitter, comprising:

a base-band process circuit for processing a base-band signal to output a base-band transmitting signal;

a transmitter circuit for converting the base-band transmitting signal to a radio frequency transmitting signal;

a first bypass switch opened or closed by means of a switch control signal, and receiving the radio frequency transmitting signal;

a first antenna receiving an output of the first bypass switch;

a second bypass switch opened or closed by means of the switch control switch, and receiving the radio frequency transmitting signal;

a power amplifier amplifying and outputting an output of the second switch; and

a second antenna receiving an output of the power amplifier.

2. The dual antenna diversity transmitter according to claim 1, wherein the switch control signal is outputted from the base-band process circuit.

3. The dual antenna diversity transmitter according to claim 1, wherein:

the switch control signal is set so that the first bypass switch is opened and the second bypass switch is closed, in case where required transmitting output power is larger than a predetermined threshold power; and

the switch control signal is set so that the first bypass switch is closed and the second bypass switch is opened, in case where the required transmitting output power is smaller than the threshold power.

4. The dual antenna diversity transmitter according to claim 3, wherein the threshold power is a maximum output power of the radio frequency transmitter circuit.

5. The dual antenna diversity transmitter according to claim 3, wherein:

the power amplifier performs amplification when the required transmitting output power is larger than the threshold power, and

the power amplifier does not perform the amplification when the required transmitting output power is smaller than the threshold power.

6. The dual antenna diversity transmitter according to claim 5, wherein the threshold power is a maximum output power of the radio frequency transmitter circuit.

7. The dual antenna diversity transmitter according to claim 1, wherein the transmitter circuit includes an amplifier having amplification capability lower than that of the power amplifier.

8. The dual antenna diversity transmitter according to claim 1, further comprising:

a first filter removing an unnecessary signal from the output signal of the first bypass switch to input to the first antenna; and

a second filter removing an unnecessary signal from the output signal of the power amplifier to input a resultant signal to the second antenna.

9. A dual antenna diversity system comprising a first antenna, a second antenna, a first diversity switch, a second diversity switch, a power amplifier, a first filter, a second filter, a transmitter circuit, a receiver circuit, a base-band process circuit, a first bypass switch, and a second bypass switch, wherein:

the transmitter circuit converts a base-band transmitting signal outputted from the base-band process circuit into a radio frequency transmitting signal;

the first bypass switch is opened or closed depending on a switch control signal, and when closed, outputs the radio frequency transmitting signal to the first filter;

the second bypass switch is opened or closed depending on the switch control signal, and when closed, outputs the radio frequency transmitting signal to the power amplifier;

the power amplifier amplifies and outputs an output of the second bypass switch;

the receiver circuit converts an inputted radio frequency receiving signal into a base-band receiving signal to output to the base-band process circuit;

the first diversity switch connects an input of the receiver circuit to the first filter or one terminal of the second diversity switch, depending on the switch control signal;

the second diversity switch connects the second filter to the output of the power amplifier or one terminal of the first diversity switch, depending on the switch control signal;

the first antenna is connected to the first filter; and

the second antenna is connected to the second filter.

10. The dual antenna diversity system according to claim 9, wherein the transmitter circuit includes an amplifier having amplification capability lower than that of the power amplifier.

11. The dual antenna diversity system according to claim 9, wherein:

the switch control signal is set so that the first bypass switch is opened and the second bypass switch is closed, in case where required transmitting output power is larger than maximum output power of the radio frequency transmitter circuit; and

the switch control signal is set so that the first bypass switch is closed and the second bypass switch is opened, in case where the required transmitting output power is smaller than the maximum output power of the radio frequency transmitter circuit.

12. The dual antenna diversity system according to claim 11, wherein the transmitter circuit includes an amplifier having amplification capability lower than that of the power amplifier.

13. The dual antenna diversity system according to claim 9, wherein:

the power amplifier performs amplification, when required transmitting output power is larger than maximum output power of the radio frequency transmitter circuit; and

the power amplifier does not perform the amplification, when the required transmitting output power is smaller than the maximum output power of the radio frequency transmitter circuit.

14. The dual antenna diversity system according to claim 13, wherein the transmitter circuit includes an amplifier having amplification capability lower than that of the power amplifier.

15. A dual antenna diversity system comprising first and second antennas, a diversity switch, a power amplifier, a transmitter circuit, a receiver circuit, a base-band process circuit, a first bypass switch, a second bypass switch, a first duplex, and a second duplex, wherein:

the transmitter circuit converts a base-band transmitting signal outputted from the base-band process circuit into a radio frequency transmitting signal;

the first bypass switch is opened or closed depending on the switch control signal, and outputs the radio frequency transmitting signal to the first duplex, when closed;

the second bypass switch is opened or closed depending on the switch control signal, and outputs the radio frequency transmitting signal to the power amplifier, when closed;

the power amplifier amplifies and outputs an output of the second bypass switch;

the receiver circuit converts an inputted radio frequency receiving signal into a base-band receiving signal to output to the base-band process circuit;

the diversity switch connects an input of the receiver circuit to the first duplex or the second duplex, depending on the switch control signal;

the first duplex transfers a signal received from the first antenna to the diversity switch, and transfers a signal inputted from the first bypass switch to the first antenna; and

the second duplex transfers a signal received from the second antenna to the diversity switch, and transfers a signal inputted from the power amplifier to the second antenna.

16. The dual antenna diversity system according to claim 15, wherein the transmitter circuit includes an amplifier having amplification capability lower than that of the power amplifier.

17. The dual antenna diversity system according to claim 15, wherein:

the switch control signal is set so that the first bypass switch is opened and the second bypass switch is closed, in case where required transmitting output power is larger than maximum output power of the radio frequency transmitter circuit; and

the switch control signal is set so that the first bypass switch is closed and the second bypass switch is opened, in case where the required transmitting output power is smaller than the maximum output power of the radio frequency transmitter circuit.

18. The dual antenna diversity system according to claim 17, wherein the transmitter circuit includes an amplifier having amplification capability lower than that of the power amplifier.

19. The dual antenna diversity system according to claim 15, wherein:

the power amplifier performs amplification when required transmitting output power is larger than maximum output power of the radio frequency transmitter circuit; and

the power amplifier does not perform the amplification when the required transmitting output power is smaller than the maximum output power of the radio frequency transmitter circuit.

20. The dual antenna diversity system according to claim 19, wherein the transmitter circuit includes an amplifier having amplification capability lower than that of the power amplifier.