ANTENNA DIVERSITY RECEIVER

• US 20090170461A1
• Filed: 08/08/2008
• Published: 07/02/2009
• Est. Priority Date: 12/29/2007
• Status: Active Grant

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Park, Tah Joon, Kim, Myeung Su, KWON, Yong Il
• Granted Patent: US 8,374,565 B2
• Time in Patent Office: Days
• US Class Current: 455/277.100
• CPC Class Codes: H04B 7/0814 based on current reception conditions, e.g. switching to different antenna when signal level is below threshold

Abstract

An antenna diversity receiver includes a plurality of antennas, an antenna selector unit, an RF module unit, a logic gate unit, a power detector unit, and a selection controller unit. The antenna selector unit selects one of the antennas. The RF module unit converts an RF RX signal received from the antenna selector unit into a baseband RX signal. The logic gate unit controls a power detection mode for detecting the power levels of RX signals and an operation mode for selecting one of the antennas. The power detector unit detects the power level of the RX signal. The selection controller unit controls the antenna selector unit to sequentially select the antennas in the power detection mode, and controls the antenna selector unit to select the antenna with a relatively good RX sensitivity among the antennas.

Claims

1. An antenna diversity receiver comprising:

a plurality of antennas;

an antenna selector unit selecting one of the antennas;

an RF module unit converting an RF receive (RX) signal received from the antenna selector unit into a baseband RX signal;

a logic gate unit controlling a power detection mode for detecting the power levels of RX signals received through the antennas and an operation mode for selecting one of the antennas on the basis of the detected power;

a power detector unit detecting the power level of the RX signal received through each of the antennas, on the basis of the RX signal received through the RF module unit, under the control of the logic gate unit; and

a selection controller unit controlling the antenna selector unit to sequentially select the antennas in the power detection mode and controlling the antenna selector unit to select the antenna with a relatively good RX sensitivity among the antennas in the operation mode on the basis of the power levels detected by the power detector unit, under the control of the logic gate unit.

2. The antenna diversity receiver of claim 1, wherein the RF module unit comprises:

a low-noise amplifier low-noise-amplifying the RF RX signal received from the antenna selector unit;

a mixer converting the RF RX signal received from the low-noise amplifier into a baseband RX signal;

a band-pass filter passing an RX signal of a predetermined band among the RX signals received from the mixer; and

a variable-gain amplifier amplifying the signal received from the band-pass filter.

3. The antenna diversity receiver of claim 2, wherein the power detector unit detects the power level of the RX signal received through each of the antennas, on the basis of the RX signal output from the band-pass filter of the RF module unit.

4. The antenna diversity receiver of claim 3, wherein the antennas comprise a first antenna and a second antenna, and the antenna selector unit comprises:

a first antenna switch configured to select the first antenna under the control of the selection controller unit; and

a second antenna switch configured to select the second antenna under the control of the selection controller unit.

5. The antenna diversity receiver of claim 4, wherein the logic gate unit generates, in the power detection mode, first and second clock signals, which are used to detect the power level of the RX signal received through the first antenna, and third and fourth clock signals, which are used to detect the power level of the RX signal received through the second antenna, to output the first and second clock signals and the third and fourth clock signals to the power detector unit;

generates, in the power detection mode, a fifth clock signal, which is used to select the first antenna or the second antenna, to output the fifth clock signal to the selection controller unit; and

generates a mode selection signal, which is used to select the fifth clock signal in the power detection mode and to select the output signal of the power detector unit in the operation mode, to output the mode selection signal to the selection controller unit.

6. The antenna diversity receiver of claim 5, wherein the power detector unit comprises:

a rectifier unit rectifying a signal received from the band-pass filter;

a first capacitor connected between a ground terminal and an output terminal of the rectifier unit to be charged with a voltage corresponding to a signal received through the first antenna;

a second capacitor connected between the ground terminal and the output terminal of the rectifier unit in parallel to the first capacitor to be charged with a voltage corresponding to a signal received through the second antenna; and

a comparator comparing a first detection voltage charged in the first capacitor with a second detection voltage charged in the second capacitor, to output a comparison result signal with regard to the first detection voltage and the second detection voltage.

7. The antenna diversity receiver of claim 6, wherein the power detector unit further comprises:

a first charge switch connected between the first capacitor and the output terminal of the rectifier unit to switch a charge path of the first capacitor in response to the first clock signal of the logic gate unit;

a second charge switch connected between the second capacitor and an output terminal of the band-pass filter to switch a charge path of the second capacitor in response to the third clock signal of the logic gate unit;

a first discharge switch connected in parallel to the both ends of the first capacitor to switch a discharge path of the first capacitor in response to the second clock signal of the logic gate unit; and

a second discharge switch connected in parallel to the both ends of the second capacitor to switch a discharge path of the second capacitor in response to the fourth clock signal of the logic gate unit.

8. The antenna diversity receiver of claim 7, wherein the selection controller unit selects and provides the fifth clock signal received from the logic gate unit to the antenna selector unit in response to the mode selection signal of the logic gate unit in the power detection mode;

and

provides a power level signal detected by the power detector unit to the antenna selector unit in response to the mode selection signal in the operation mode.

9. The antenna diversity receiver of claim 8, wherein in the power detection mode, when the fifth clock signal is used to select the first antenna, the logic gate unit uses the first and second clock signals to control the first charge switch/the first discharge switch to be off/on for discharge of the first capacitor, and then uses the first and second clock signals to control the first antenna switch/the first charge switch/the first discharge switch to be on/on/off for detection of the first detection voltage through charge of the first capacitor.

10. The antenna diversity receiver of claim 8, wherein in the power detection mode, when the fifth clock signal is used to select the second antenna, the logic gate unit uses the third and fourth clock signals to control the second charge switch/the second discharge switch to be off/on for discharge of the second capacitor, and then uses the third and fourth clock signals to control the second antenna switch/the second charge switch/the second discharge switch to be on/on/off for detection of the second detection voltage through charge of the second capacitor.

11. The antenna diversity receiver of claim 8, wherein if the first detection voltage is higher than the second detection voltage, the power detector unit outputs a signal for selection of the first antenna;

and if the first detection voltage is not higher than the second detection voltage, the power detector unit outputs a signal for selection of the second antenna.

12. The antenna diversity receiver of claim 11, wherein in the operation mode, the logic gate unit selects and provides an output signal of the power detector unit to the first and second antenna switches of the antenna selector unit, so that on the basis of the output signal of the power detector unit, the logic gate unit controls the first antenna switch to select the first antenna if the first detection voltage is higher than the second detection voltage, and controls the second antenna switch to select the second antenna if the first detection voltage is not higher than the second detection voltage.

13. An antenna diversity receiver comprising:

a plurality of antennas;

an antenna selector unit selecting one of the antennas;

an RF module unit converting an RF receive (RX) signal received from the antenna selector unit into a baseband RX signal;

a logic gate unit controlling a power detection mode for detecting the power levels of RX signals received through the antennas and an operation mode for selecting one of the antennas on the basis of the detected power;

a power detector unit detecting the power level of the RX signal received through each of the antennas, on the basis of the RX signal received through the RF module unit, under the control of the logic gate unit;

a selection controller unit controlling the antenna selector unit to sequentially select the antennas in the power detection mode and controlling the antenna selector unit to select the antenna with a relatively good RX sensitivity among the antennas in the operation mode on the basis of the power levels detected by the power detector unit, under the control of the logic gate unit; and

a wake-up determiner unit determining whether the power level detected by the power detector unit is higher than a predetermined wake-up power level, and outputting a wake-up signal if the detected power level is higher than the predetermined wake-up power level.

14. The antenna diversity receiver of claim 13, wherein the RF module unit comprises:

a low-noise amplifier low-noise-amplifying the RF RX signal received from the antenna selector unit;

a mixer converting the RF RX signal received from the low-noise amplifier into a baseband RX signal;

a band-pass filter passing an RX signal of a predetermined band among the RX signals received from the mixer; and

a variable-gain amplifier amplifying the signal received from the band-pass filter.

15. The antenna diversity receiver of claim 14, wherein the power detector unit detects the power level of the RX signal received through each of the antennas, on the basis of the RX signal output from the band-pass filter of the RF module unit.

16. The antenna diversity receiver of claim 15, wherein the antennas comprise a first antenna and a second antenna, and the antenna selector unit comprises:

a first antenna switch configured to select the first antenna under the control of the selection controller unit; and

a second antenna switch configured to select the second antenna under the control of the selection controller unit.

17. The antenna diversity receiver of claim 16, wherein the logic gate unit generates, in the power detection mode, first and second clock signals, which are used to detect the power level of the RX signal received through the first antenna, and third and fourth clock signals, which are used to detect the power level of the RX signal received through the second antenna, to output the first and second clock signals and the third and fourth clock signals to the power detector unit;

generates, in the power detection mode, a fifth clock signal, which is used to select the first antenna or the second antenna, to output the fifth clock signal to the selection controller unit; and

generates a mode selection signal, which is used to select the fifth clock signal in the power detection mode and to select the output signal of the power detector unit in the operation mode, to output the mode selection signal to the selection controller unit.

18. The antenna diversity receiver of claim 17, wherein the power detector unit comprises:

a rectifier unit rectifying a signal received from the band-pass filter;

a first capacitor connected between a ground terminal and an output terminal of the rectifier unit to be charged with a voltage corresponding to a signal received through the first antenna;

a second capacitor connected between the ground terminal and the output terminal of the rectifier unit in parallel to the first capacitor to be charged with a voltage corresponding to a signal received through the second antenna; and

a comparator comparing a first detection voltage charged in the first capacitor with a second detection voltage charged in the second capacitor, to output a comparison result signal with regard to the first detection voltage and the second detection voltage.

19. The antenna diversity receiver of claim 18, wherein the power detector unit further comprises:

a first charge switch connected between the first capacitor and the output terminal of the rectifier unit to switch a charge path of the first capacitor in response to the first clock signal of the logic gate unit;

a second charge switch connected between the second capacitor and an output terminal of the band-pass filter to switch a charge path of the second capacitor in response to the third clock signal of the logic gate unit;

a first discharge switch connected in parallel to the both ends of the first capacitor to switch a discharge path of the first capacitor in response to the second clock signal of the logic gate unit; and

a second discharge switch connected in parallel to the both ends of the second capacitor to switch a discharge path of the second capacitor in response to the fourth clock signal of the logic gate unit.

20. The antenna diversity receiver of claim 19, wherein the selection controller unit selects and provides the fifth clock signal received from the logic gate unit to the antenna selector unit in response to the mode selection signal of the logic gate unit in the power detection mode;

and

provides a power level signal detected by the power detector unit to the antenna selector unit in response to the mode selection signal in the operation mode.

21. The antenna diversity receiver of claim 20, wherein in the power detection mode, when the fifth clock signal is used to select the first antenna, the logic gate unit uses the first and second clock signals to control the first charge switch/the first discharge switch to be off/on for discharge of the first capacitor, and then uses the first and second clock signals to control the first antenna switch/the first charge switch/the first discharge switch to be on/on/off for detection of the first detection voltage through charge of the first capacitor.

22. The antenna diversity receiver of claim 20, wherein in the power detection mode, when the fifth clock signal is used to select the second antenna, the logic gate unit uses the third and fourth clock signals to control the second charge switch/the second discharge switch to be off/on for discharge of the second capacitor, and then uses the third and fourth clock signals to control the second antenna switch/the second charge switch/the second discharge switch to be on/on/off for detection of the second detection voltage through charge of the second capacitor.

23. The antenna diversity receiver of claim 22, wherein if the first detection voltage is higher than the second detection voltage, the power detector unit outputs a signal for selection of the first antenna;

and if the first detection voltage is not higher than the second detection voltage, the power detector unit outputs a signal for selection of the second antenna.

24. The antenna diversity receiver of claim 23, wherein in the operation mode, the logic gate unit selects and provides an output signal of the power detector unit to the first and second antenna switches of the antenna selector unit, so that on the basis of the output signal of the power detector unit, the logic gate unit controls the first antenna switch to select the first antenna if the first detection voltage is higher than the second detection voltage, and controls the second antenna switch to select the second antenna if the first detection voltage is not higher than the second detection voltage.