Cellular mobile telephone terminal

• US 6,337,974 B1
• Filed: 05/26/2000
• Issued: 01/08/2002
• Est. Priority Date: 05/31/1999
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Inamori, Masahiko, Motoyoshi, Kaname, Tara, Katsushi
• Primary Examiner(s): TO, DORIS HA
• Application Number:
  US09/578,468
• Time in Patent Office: 592 Days
• Field of Search: 455/422, 455/126, 455/522, 455/69, 455/70, 455/73, 455/575, 455/127, 455/232.1, 455/234--23, 455/239.1, 327/308, 327/306, 327/318, 327/324, 327/327-328, 327/560-563, 330/278
• US Class Current: 455/126
• CPC Class Codes: H03G 1/007 using FET type devices
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04
• 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

To achieve linear gain control (with a flatness of ±1 dB) over a wide range of 70 dB or greater using a single control voltage, an attenuator of the following configuration is provided in a radio frequency section of a transmitter of a cellular mobile telephone terminal. That is, a signal inputpart (34) and signal output part (35) for a radio frequency signal are connected by a signal line (51) containing at least two series variable resistors (51 and 52); parallel variable resistors (53 and 54) are connected between a ground line (57) and the signal inputpart (34) and signal outputpart (35), respectively; a gain control line (56) is connected to the variable resistors (51, 52, 53, and 54); reference voltage application parts (23, 27, 31, and 33) are connected to the variable resistors (51, 52, 53, and 54), respectively; and a gain control voltage application part (19) is connected to each of the variable resistors (51, 52, 53, and 54) via the gain control line (56).

Claims

1. A cellular mobile telephone terminal comprising a baseband section (101) for processing a voice signal and a radio transceiver section (210) for taking as an input the voice signal processed by said baseband section (101) and for performing communications with a base station, wherein said radio transceiver section (201) comprises a transmitter section (250) for generating a signal for transmission to said base station and a receiver section (220) for receiving a signal transmitted from said base station, said transmitter section (250) comprising an intermediate frequency section (260) for performing heterodyning for modulation and frequency conversion of the voice signal supplied from said baseband section (101) and a radio frequency section (270) for amplifying a radio frequency signal output from said intermediate frequency section (260) and for supplying said amplified signal to an antenna, said radio frequency section (270) comprising a gain controller (271) for controlling the gain of said radio frequency signal output from said intermediate frequency section (260) and a power amplifier (242) for amplifying the power of an output of said gain controller (271), and wherein:

said baseband section (101) includes a control section, and said control section detects the output level of said power amplifier (242) while also detecting signal strength of the signal received by said receiver section (220), sets an output level target value for said power amplifier (242) based on the signal strength of said received signal, compares the output level of said power amplifier (242) with said output level target value of said power amplifier (242), and applies to said gain controller (271) a gain control voltage responsive to the result of said comparison, thereby controlling the gain of said gain controller (271) in a feedback loop so that the output level of said power amplifier (242) matches said output level target value of said power amplifier (242); and

said gain controller (271) comprises;

a signal line (55) containing at least two series variable resistors (51) and (52) and connecting between a signal input part (34) and signal output part (35) for said radio frequency signal; and

parallel variable resistors (53) and (54) connected between a groundline (57) and said signal input part (34) and signal output part (35), respectively, wherein said gain controller (271) controls the output of said power amplifier (242) linearly and in substantially continuous fashion by controlling the gain of each of said variable resistors (51), (52), (53), and (54) through said gain control voltage which is applied to a gain control voltage application part (19).

2. A cellular mobile telephone terminal comprising a baseband section (101) for processing a voice signal and a radio transceiver section (210) for taking as an input the voice signal processed by said baseband section (101) and for performing communications with a base station, wherein said radio transceiver section (201) comprises a transmitter section (250) for generating a signal for transmission to said base station and a receiver section (220) for receiving a signal transmitted from said base station, said transmitter section (250) comprising an intermediate frequency section (260) for performing heterodyning for modulation and frequency conversion of the voice signal supplied from said baseband section (101) and a radio frequency section (270) for amplifying a radio frequency signal output from said intermediate frequency section (260) and for supplying said amplified signal to an antenna, said radio frequency section (270) comprising a gain controller (271) for controlling the gain of said radio frequency signal output from said intermediate frequency section (260) and a power amplifier (242) for amplifying the power of an output of said gain controller (271), and wherein:

said baseband section (101) includes a control section, and said control section detects the output level of said power amplifier (242) while also detecting signal strength of the signal received by said receiver section (220), sets an output level target value for said power amplifier (242) based on the signal strength of said received signal, compares the output level of said power amplifier (242) with said output level target value of said power amplifier (242), and applies to said gain controller (271) a gain control voltage responsive to the result of said comparison, thereby controlling the gain of said gain controller (271) in a feedback loop so that the output level of said power amplifier (242) matches said output level target value of said power amplifier (242); and

said gain controller (271) comprises;

a signal line (55) containing at least two series variable resistors (51) and (52) and connecting between a signal input part (34) and signal output part (35) for said radio frequency signal;

parallel variable resistors (53) and (54) connected between a ground line (57) and said signal input part (34) and signal output part (35), respectively;

a gain control line (56) connected to said variable resistors (51), (52), (53), and (54);

reference voltage application parts (23), (27), (31), and (33) connected to said variable resistors (51), (52), (53), and (54), respectively; and

a gain control voltage application part (19) connected to each of said variable resistors (51), (52), (53), and (54) via said gain control line (56) for application of said gain control voltage.

3. A cellular mobile telephone terminal according to claim 2, wherein said variable resistors (51), (52), (53), and (54) are formed at least from field effect transistors (21), (25), (16), and (28) whose gates are connected to resistors (22), (26), (20), and (32), respectively, and wherein:

the gates of said field effect transistors (21) and (25) forming said variable resistors (51) and (52) are connected to said gain control voltage application part (19) via said resistors (22) and (26), respectively, and via said gain control line (56);

the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said reference voltage application parts (31) and (33) via said resistors (20) and (32), respectively;

the sources of said field effect transistors (21) and (25) forming said variable resistors (51) and (52) are connected to said reference voltage application parts (23) and (27), respectively, said variable resistors (51) and (52) being connected in series via a capacitor (24);

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said gain control voltage application part (19) via said gain control line (56);

the drains of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected via capacitors (17) and (29) to said signal input part (34) and said signal output part (35), respectively; and

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to a base potential part (GND) via capacitors (18) and (30), respectively, and via said ground line (57).

4. A cellular mobile telephone terminal according to claim 2, wherein a voltage applied to said reference voltage application part (23) is higher than a voltage applied to said reference voltage application part (27).

5. A cellular mobile telephone terminal according to claim 2, wherein a voltage applied to said reference voltage application part (23) is higher than a voltage applied to said reference voltage application part (27) by a value corresponding to a gain control voltage range where said variable resistor (52) performs a linear gain control operation.

6. A cellular mobile telephone terminal according to claim 2, wherein the values of voltages applied to said reference voltage application parts (31) and (33) are set so that a gain control voltage range where said variable resistors (53) and (54) perform a linear gain control operation becomes continuous with a gain control voltage range where said variable resistors (51) and (52) perform a linear gain control operation.

7. A cellular mobile telephone terminal according to claim 2, wherein said variable resistors (51), (52), (53), and (54) are formed at least from field effect transistors (21), (25), (16), and (28) whose gates are connected to resistors (22), (26), (20), and (32), respectively, and wherein:

the gates of said field effect transistors (21) and (25) forming said variable resistors (51) and (52) are connected to said gain control voltage application part (19) via said resistors (22) and (26), respectively, and via said gain control line (56);

the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected together via said resistors (20) and (32);

a resistor (38) is inserted between the sources of said field effect transistors (21) and (25) forming said variable resistors (51) and (52);

a resistor (39) is inserted between the source of said field effect transistor (25) forming said variable resistor (52) and a part (61) connected via said resistors (20) and (32) to the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54);

a resistor (40) is inserted between a base potential part (GND) and said part (61) connected via said resistors (20) and (32) to the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54);

said reference voltage application part (23) is connected to the source of said field effect transistor (21) forming said variable resistor (51);

said variable resistors (51) and (52) are connected in series via a capacitor (24);

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said gain control voltage application part (19) via said gain control line (56);

the drains of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected via capacitors (17) and (29) to said signal input part (34) and said signal output part (35), respectively; and

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said base potential part (GND) via capacitors (18) and (30), respectively, and via said ground line (57).

8. A cellular mobile telephone terminal comprising a baseband section (101) for processing a voice signal and a radio transceiver section (210) for taking as an input the voice signal processed by said baseband section (101) and for performing communications with a base station, wherein said radio transceiver section (201) comprises a transmitter section (250) for generating a signal for transmission to said base station and a receiver section (220) for receiving a signal transmitted from said base station, said transmitter section (250) comprising an intermediate frequency section (260) for performing heterodyning for modulation and frequency conversion of the voice signal supplied from said baseband section (101) and a radio frequency section (270) for amplifying a radio frequency signal output from said intermediate frequency section (260) and for supplying said amplified signal to an antenna, said radio frequency section (270) comprising a gain controller (271) for controlling the gain of said radio frequency signal output from said intermediate frequency section (260) and a power amplifier (242) for amplifying the power of an output of said gain controller (271), and wherein:

said baseband section (101) includes a control section, and said control section detects the output level of said power amplifier (242) while also detecting signal strength of the signal received by said receiver section (220), sets an output level target value for said power amplifier (242) based on the signal strength of said received signal, compares the output level of said power amplifier (242) with said output level target value of said power amplifier (242), and applies to said gain controller (271) first and second gain control voltages responsive to the result of said comparison, thereby controlling the gain of said gain controller (271) in a feedback loop so that the output level of said power amplifier (242) matches said output level target value of said power amplifier (242); and

said gain controller (271) comprises;

a signal line (55) containing at least two series variable resistors (51) and (52) and connecting between a signal input part (34) and signal output part (35) for said radio frequency signal;

parallel variable resistors (53) and (54) connected between a ground line (57) and said signal input part (34) and signal output part (35), respectively;

a first gain control line (58) connected to said variable resistor (51);

a gain control voltage application part (42) connected to said variable resistor (51) via said first gain control line (58) for application of said first gain control voltage;

a second gain control line (59) connected to said variable resistors (52), (53), and (54);

a gain control voltage application part (19) connected to said variable resistors (52), (53), and (54) via said second gain control line (59) for application of said second gain control voltage;

a reference voltage application part (23) connected to said variable resistors (51) and (52); and

reference voltage application parts (31) and (33) connected to said variable resistors (53) and (54), respectively.

9. A cellular mobile telephone terminal according to claim 8, wherein said variable resistors (51), (52), (53), and (54) are formed at least from field effect transistors (21), (25), (16), and (28) whose gates are connected to resistors (22), (26), (20), and (32), respectively, and wherein:

the gate of said field effect transistor (21) forming said variable resistor (51) is connected to said gain control voltage application part (42) via said resistor (22) and via said first gain control line (58);

the gate of said field effect transistor (25) forming said variable resistor (52) is connected to said gain control voltage application part (19) via said resistor (26) and via said second gain control line (59);

the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said reference voltage application parts (31) and (33) via said resistors (20) and (32), respectively;

a resistor (41) is inserted between the sources of said field effect transistors (21) and (25) forming said variable resistors (51) and (52);

the source of said variable resistor (52) is connected to said reference voltage application part (23);

said variable resistors (51) and (52) are connected in series via a capacitor (24);

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said gain control voltage application part (19) via said second gain control line (59);

the drains of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected via capacitors (17) and (29) to said signal input part (34) and said signal output part (35), respectively; and

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said base potential part (GND) via capacitors (18) and (30), respectively, and via said ground line (57).

10. A cellular mobile telephone terminal according to claim 8, wherein a voltage applied to said gain control voltage application part (19) is higher than a voltage applied to said gain control voltage application part (42).

11. A cellular mobile telephone terminal according to claim 8, wherein a voltage applied to said gain control voltage application part (19) is higher than a voltage applied to said gain control voltage application part (42) by a value corresponding to a gain control voltage range where said variable resistor (52) performs a linear gain control operation.

12. A cellular mobile telephone terminal according to claim 8, wherein the values of voltages applied to said reference voltage application parts (31) and (33) are set so that a gain control voltage range where said variable resistors (53) and (54) perform a linear gain control operation becomes continuous with a gain control voltage range where said variable resistors (51) and (52) perform a linear gain control operation.

13. A cellular mobile telephone terminal according to claim 8, wherein said variable resistors (51), (52), (53), and (54) are formed at least from field effect transistors (21), (25), (16), and (28) whose gates are connected to resistors (22), (26), (20), and (32), respectively, and wherein:

the gate of said field effect transistor (21) forming said variable resistor (51) is connected to said gain control voltage application part (42) via said resistor (22) and via said first gain control line (58);

the gate of said field effect transistor (25) forming said variable resistor (52) is connected to said gain control voltage application part (19) via said resistor (26) and via said second gain control line (59);

the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected together via said resistors (20) and (32);

a resistor (41) is inserted between the sources of said field effect transistors (21) and (25) forming said variable resistors (51) and (52);

a resistor (39) is inserted between the source of said field effect transistor (25) forming said variable resistor (52) and a part (61) connected via said resistors (20) and (32) to the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54);

a resistor (40) is inserted between a base potential part (GND) and said part (61) connected via said resistors (20) and (32) to the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54);

said reference voltage application part (23) is connected to the source of said field effect transistor (25) forming said variable resistor (52);

said variable resistors (51) and (52) are connected in series via a capacitor (24);

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said gain control voltage application part (19) via said second gain control line (59);

the drains of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected via capacitors (17) and (29) to said signal input part (34) and said signal output part (35), respectively; and

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said base potential part (GND) via capacitors (18) and (30), respectively, and via said ground line (57).

14. A cellular mobile telephone terminal comprising a baseband section (101) for processing a voice signal and a radio transceiver section (210) for taking as an input the voice signal processed by said baseband section (101) and for performing communications with a base station, wherein said radio transceiver section (201) comprises a transmitter section (250) for generating a signal for transmission to said base station and a receiver section (220) for receiving a signal transmitted from said base station, said transmitter section (250) comprising an intermediate frequency section (260) for performing heterodyning for modulation and frequency conversion of the voice signal supplied from said baseband section (101) and a radio frequency section (270) for amplifying a radio frequency signal output from said intermediate frequency section (260) and for supplying said amplified signal to an antenna, said radio frequency section (270) comprising a gain controller (271) for controlling the gain of said radio frequency signal output from said intermediate frequency section (260) and a power amplifier (242) for amplifying the power of an output of said gain controller (271), and wherein:

said baseband section (101) includes a control section, and said control section detects the output level of said power amplifier (242) while also detecting signal strength of the signal received by said receiver section (220), sets an output level target value for said power amplifier (242) based on the signal strength of said received signal, compares the output level of said power amplifier (242) with said output level target value of said power amplifier (242), and applies to said gain controller (271) a gain control voltage responsive to the result of said comparison, thereby controlling the gain of said gain controller (271) in a feedback loop so that the output level of said power amplifier (242) matches said output level target value of said power amplifier (242); and

said gain controller (271) comprises;

a signal line (55) containing at least two series variable resistors (51) and (52) and connecting between a signal input part (34) and signal output part (35) for said radio frequency signal;

parallel variable resistors (53) and (54) connected between aground line (57) and said signal input part (34) and signal output part (35), respectively;

a gain control line (56) connecting between said variable resistors (51), (52), (53), and (54);

a gain control voltage application part (19) connected to said variable resistors (51), (52), (53), and (54) via said gain control line (56) for application of said gain control voltage;

a reference voltage application part (23) connected to said variable resistors (51) and (52); and

reference voltage application parts (31) and (33) connected to said variable resistors (53) and (54), respectively.

15. A cellular mobile telephone terminal according to claim 14, wherein said variable resistors (51), (52), (53), and (54) are formed at least from field effect transistors (21), (25), (16), and (28) whose gates are connected to resistors (22), (26), (20), and (32), respectively, and wherein:

the gates of said field effect transistors (21) and (25) forming said variable resistors (51) and (52) are connected to said gain control voltage application part (19) via said resistors (22) and (26), respectively, and via said gain control line (56);

the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said reference voltage application parts (31) and (33) via said resistors (20) and (32), respectively;

a resistor (41) is inserted between the sources of said field effect transistors (21) and (25) forming said variable resistors (51) and (52);

said reference voltage application part (23) is connected to the source of said variable resistor (52);

said variable resistors (51) and (52) are connected in series via a capacitor (24);

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said gain control voltage application part (19) via said gain control line (56);

the drains of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected via capacitors (17) and (29) to said signal input part (34) and said signal output part (35), respectively; and

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to a base potential part (GND) via capacitors (18) and (30), respectively, and via said ground line (57).

16. A cellular mobile telephone terminal according to claim 14, wherein said field effect transistor (21) forming said variable resistor (51) is chosen to have a threshold voltage higher than the threshold voltage of said field effect transistor (25) forming said variable resistor (52).

17. A cellular mobile telephone terminal according to claim 14, wherein said field effect transistor (21) forming said variable resistor (51) is chosen to have a threshold voltage higher than the threshold voltage of said field effect transistor (25) forming said variable resistor (52) by a value corresponding to a gain control voltage range where said variable resistor (52) performs a linear gain control operation.

18. A cellular mobile telephone terminal according to claim 14, wherein the values of voltages applied to said reference voltage application parts (31) and (33) are set so that a gain control voltage range where said variable resistors (53) and (54) perform a linear gain control operation becomes continuous with a gain control voltage range where said variable resistors (51) and (52) perform a linear gain control operation.

19. A cellular mobile telephone terminal according to claim 14, wherein said variable resistors (51), (52), (53), and (54) are formed at least from field effect transistors (21), (25), (16), and (28) whose gates are connected to resistors (22), (26), (20), and (32), respectively, and wherein:

the gates of said field effect transistors (21) and (25) forming said variable resistors (51) and (52) are connected to said gain control voltage application part (42) via said resistors (22) and (26), respectively, and via said gain control line (56);

the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected together via said resistors (20) and (32);

a resistor (41) is inserted between the sources of said field effect transistors (21) and (25) forming said variable resistors (51) and (52);

a resistor (39) is inserted between the source of said field effect transistor (25) forming said variable resistor (52) and a part (61) connected via said resistors (20) and (32) to the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54);

a resistor (40) is inserted between a base potential part (GND) and said part (61) connected via said resistors (20) and (32) to the gates of said field effect transistors (16) and (28) forming said variable resistors (53) and (54);

said reference voltage application part (23) is connected to the source of said field effect transistor (25) forming said variable resistor (52);

said variable resistors (51) and (52) are connected in series via a capacitor (24);

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said gain control voltage application part (19) via said gain control line (56);

the drains of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected via capacitors (17) and (29) to said signal input part (34) and said signal output part (35), respectively; and

the sources of said field effect transistors (16) and (28) forming said variable resistors (53) and (54) are connected to said base potential part (GND) via capacitors (18) and (30), respectively, and via said ground line (57).