Communication apparatus

• US 20050245213A1
• Filed: 03/09/2005
• Published: 11/03/2005
• Est. Priority Date: 04/28/2004
• Status: Active Grant

• Current Assignee: Hitachi Kokusai Electric Incorporated (Hitachi, Ltd.)
• Original Assignee: Hitachi Kokusai Electric Incorporated (Hitachi, Ltd.)
• Inventors: Hirano, Takayuki, Suzuki, Yasuhiko
• Granted Patent: US 7,383,023 B2
• Time in Patent Office: Days
• US Class Current: 455/127.100
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 2200/78 A comparator being used in a controlling circuit of an amplifier
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04

Abstract

In a communication apparatus, effective automatic power control (APC) is realized. Transmission object signal level changing units change a level of a transmission object signal of each channel, and transmission filter units carry out filtering for a signal of each channel after its level was changed with a characteristic for allowing a passage of a frequency component of each channel, and a transmission signal coupling unit couples signals of plural channels after the filtering was carried out, and an antenna transmits a coupled signal by wireless, and coupled signal dividing units divide a part of the coupled signal into a plurality of signals, and level detection filter units carry out filtering for each divided signal with an identical characteristic to the above-described characteristic, and signal level detecting units detect a level of a signal of each channel after the filtering was carried out, and a transmission object signal level change mode controlling unit controls a level change mode of a transmission object signal of each channel on the basis of the detection result.

Claims

1. A communication apparatus which communicates a signal, comprising:

a transmission object signal level changing unit which changes a level of a signal which becomes, as to each of plural channels, a transmission object of each channel;

a transmission filter unit which carries out filtering for a signal of each channel, of which a level was changed by the transmission object signal level changing unit, by a filtering characteristic for allowing passage of a frequency component of each channel, as to each of the plural channels;

a transmission signal coupling unit which couples signals of the plural channels, for which filtering was carried out by the transmission filter unit;

an antenna which transmits a signal which was coupled by the transmission signal coupling unit, by wireless;

a coupled signal dividing unit which divides a part of the coupled signal which is outputted from the transmission signal coupling unit to the antenna, into a plurality of signals;

a level detection filter unit which carries out filtering each divided signal which was divided up by the coupled signal dividing unit, by a filtering characteristic which is tuned to an identical frequency to that of the filtering characteristic of the transmission filter unit, as to each of the plural channels;

a signal level detecting unit which detects a level of a signal of each channel, which was obtained by filtering due to the level detection filter unit; and

a transmission object signal level change mode controlling unit which controls a mode of changing a level of a signal which becomes a transmission object of each channel, by the transmission object signal level changing unit, on the basis of a level of a signal of each channel, which was detected by the signal level detecting unit.

2. The communication apparatus as set forth in claim 1, wherein

the transmission object signal level changing unit is configured by a plurality of variable amplifiers, and

the transmission filter unit is configured by a plurality of variable filters, and

the transmission signal coupling unit is configured by a coupling circuit which couples a plurality of signals through a plurality of series resonant circuits, and

the coupled signal dividing unit is configured by a directional coupler and a four divider, and

the level detection filter unit is configured by a plurality of variable filters, and

the signal level detecting unit is configured by a plurality of wave detectors, and

the transmission object signal level change mode controlling unit is configured by a control section.

3. The communication apparatus as set forth in claim 2, wherein

a plurality of power amplifiers are disposed between the plurality of variable amplifiers which configure the transmission object signal level changing unit, and the plurality of variable filters which configure the transmission filter unit.

4. The communication apparatus as set forth in claim 3, wherein

an attenuator is disposed between the four divider which configures the coupled signal dividing unit, and the plurality of variable filters which configure the level detection filter unit.

5. The communication apparatus as set forth in claim 1, wherein

the communication apparatus is a wireless communication apparatus which carries out multicarrier communication by a frequency hopping system.

6. The communication apparatus as set forth in claim 2, wherein

the communication apparatus is a wireless communication apparatus which carries out multicarrier communication by a frequency hopping system.

7. The communication apparatus as set forth in claim 3, wherein

the communication apparatus is a wireless communication apparatus which carries out multicarrier communication by a frequency hopping system.

8. The communication apparatus as set forth in claim 4, wherein

the communication apparatus is a wireless communication apparatus which carries out multicarrier communication by a frequency hopping system.

9. A communication apparatus which communicates a signal, comprising:

a modulating signal level changing unit which changes a level of a modulating signal which becomes a transmission object;

a pre-level change modulating signal level detecting unit which detects a level of a modulating signal before its level is changed by the modulating signal level changing unit;

a detection level predetermined value synthesizing unit which synthesizes a level which was detected by the pre-level change modulating signal level detecting unit, and a predetermined value based on a transmission level which becomes a target and is independent of a modulation system;

a post-level change modulating signal level detecting unit which detects a level of a modulating signal after its level was changed by the modulating signal level changing unit, by an identical detection characteristic to that of the pre-level change modulating signal level detecting unit; and

a modulating signal level change mode controlling unit which controls a mode of changing a level of a modulating signal which becomes a transmission object, by the modulating signal level changing unit, on the basis of a difference of a synthesis result by the detection level predetermined value synthesizing unit, and a level which was detected by the post-level change modulating signal level detecting unit.

10. The communication apparatus as set forth in claim 9, wherein

the modulating signal level changing unit is configured by a voltage-controlled gain controller, and

the pre-level change modulating signal level detecting unit is configured by a directional coupler and a logarithmic amplifier, and

the detection level predetermined value synthesizing unit is configured by a first reference voltage source and a first adder as to a first reference voltage, a second reference voltage source and a second adder as to a second reference voltage, and

the post-level change modulating signal level detecting unit is configured by a directional coupler and a logarithmic amplifier, and

the modulating signal level change mode controlling unit is configured by use of a differential amplifier.

11. The communication apparatus as set forth in claim 10, wherein

the modulating signal level change mode controlling unit is configured by a differential amplifier and an integrator, and

a filter is disposed between the logarithmic amplifier which configures the pre-level change modulating signal level detecting unit, and the first adder which configures the detection level predetermined value synthesizing unit.

12. The communication apparatus as set forth in claim 10, wherein

the modulating signal level change mode controlling unit is configured by a differential amplifier and an integrator, and

a delay device is disposed between the logarithmic amplifier which configures the pre-level change modulating signal level detecting unit, and the first adder which configures the detection level predetermined value synthesizing unit.

13. The communication apparatus as set forth in claim 10, further comprising:

a level/slope converting circuit which applies a level/slope conversion to a signal which is outputted from the second adder which configures the detection level predetermined value synthesizing unit, to output it; and

a switch which switches over an output from the level/slope converting circuit, and an output from the differential amplifier which configures the modulating signal level change mode controlling unit, to have one output inputted as a gain control signal of the voltage-controlled gain controller which configures the modulating signal level changing unit.

14. The communication apparatus as set forth in claim 11, further comprising:

a level/slope converting circuit which applies a level/slope conversion to a signal which is outputted from the second adder which configures the detection level predetermined value synthesizing unit, to output it; and

a switch which switches over an output from the level/slope converting circuit, and an output from the integrator which configures the modulating signal level change mode controlling unit, to have one output inputted as a gain control signal of the voltage-controlled gain controller which configures the modulating signal level changing unit.

15. The communication apparatus as set forth in claim 12, further comprising:

a level/slope converting circuit which applies a level/slope conversion to a signal which is outputted from the second adder which configures the detection level predetermined value synthesizing unit, to output it; and

a switch which switches over an output from the level/slope converting circuit, and an output from the integrator which configures the modulating signal level change mode controlling unit, to have one output inputted as a gain control signal of the voltage-controlled gain controller which configures the modulating signal level changing unit.

16. The communication apparatus as set forth in claim 9, wherein

the communication apparatus is a wireless communication apparatus which carries out multicarrier communication by a frequency hopping system.

17. The communication apparatus as set forth in claim 10, wherein

the communication apparatus is a wireless communication apparatus which carries out multicarrier communication by a frequency hopping system.

18. The communication apparatus as set forth in claim 11, wherein

the communication apparatus is a wireless communication apparatus which carries out multicarrier communication by a frequency hopping system.

19. The communication apparatus as set forth in claim 12, wherein

the communication apparatus is a wireless communication apparatus which carries out multicarrier communication by a frequency hopping system.

20. A communication apparatus which communicates a signal, comprising:

a transmission object signal level changing unit which changes a level of a signal which becomes, as to each of plural channels, a transmission object of each channel;

a transmission filter unit which carries out filtering for a signal of each channel, of which a level was changed by the transmission object signal level changing unit, by a filtering characteristic for allowing passage of a frequency component of each channel, as to each of the plural channels;

a transmission signal coupling unit which couples signals of the plural channels, for which filtering was carried out by the transmission filter unit;

an antenna which transmits a signal which was coupled by the transmission signal coupling unit, by wireless;

a pre-level change signal level detecting unit which detects a level of a signal before its level is changed by the transmission object signal level changing unit, as to each of the plural channels;

a detection level predetermined value synthesizing unit which synthesizes a level which was detected by the pre-level change signal level detecting unit, as to each of the plural channels, and a predetermined value based on a transmission level which becomes a target and is independent of a modulation system;

a coupled signal dividing unit which divides a part of the coupled signal which is outputted from the transmission signal coupling unit to the antenna, into a plurality of signals;

a level detection filter unit which carries out filtering each divided signal which was divided up by the coupled signal dividing unit, by a filtering characteristic which is tuned to an identical frequency to that of the filtering characteristic of the transmission filter unit, as to each of the plural channels;

a signal level detecting unit which detects a level of a signal of each channel, which was obtained by filtering due to the level detection filter unit by a detection characteristic identical to that of the pre-level change signal level detecting unit; and

a transmission object signal level change mode controlling unit which controls a mode of changing a level of a signal which becomes a transmission object, by the transmission object signal level changing unit, on the basis of a difference of a synthesis result by the detection level predetermined value synthesizing unit and a level which was detected by the signal level detecting unit as to each of the plural channels.