JP2003298446A - Radio communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technology in which power consumption is suppressed, particularly, an operable time using a battery of a radio communication device is extended by reducing power to be consumed while a diode switch is turned on. <P>SOLUTION: In the radio communication equipment for using a plurality of filters 11, 12 and 13 while alternatively switching them, the radio communication device is provided with a plurality of diode switches 21, 22 and 23 for alternatively switching the plurality of filters, an impression means 3 for impressing any one of the plurality of diode switches with a forward voltage and a control means 4 for controlling a forward current to flow to any one diode switch turned on by applying the forward voltage into suppressed state or non-suppressed state and when it is desired to reduce the power consumption of the radio communication device, the forward current to flow to the diode switch is suppressed by the control means. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a radio communication device which uses a plurality of filters by selectively switching the filters, and more particularly to a diode used for switching the filters. The present invention relates to a technology for saving power of a switch. 2. Description of the Related Art Conventionally, diode switches have been used in various parts of wireless communication devices. The on / off operation of the diode switch is controlled by turning on the diode switch by passing a forward current through the diode switch, and turning off the diode switch by stopping the forward current. I have. When on / off control of an analog signal is performed by a diode switch, it is necessary to supply a sufficient forward current to reduce distortion of a passing analog signal during an on operation. For example, in HF band transceivers and receivers, IMD characteristics (resistance characteristics against distortion of a circuit caused by strong radio waves from a broadcasting station, a business station, etc., and reception of a target signal being disturbed) are important. Is seen. In the case of a transceiver (HF band transceiver) and a receiver, a plurality of bands for selectively passing a received signal in order to obtain excellent IMD characteristics and to improve other performances. A pass filter is used. For switching these bandpass filters, a diode switch is often employed as shown in FIG. In FIG. 3, reference numerals 101, 102, and 103 denote bandpass filters having different characteristics, which are configured to be switched by switching circuits 201, 202, and 203 using diode switches. In the switching circuit, when a switching control voltage is applied from the control circuit 300, the applied diode is turned on and the signal becomes conductive, and the bandpass filter is selected. That is, when the selection command signal is input to the control circuit 300, the control voltage for switching is applied only to the switching circuit specified by the selection command signal, so that only the applied switching circuit is turned on, and The bandpass filter is selected and switched. Not only the switching of the band-pass filter, but a large number of diode switches are employed as various switching means in the wireless communication device. However, in the case of the conventional switching circuit using a diode switch as described above, it is necessary to keep a forward current flowing continuously while the switching circuit is turned on. Therefore, when a large number of diode switches are used, the total amount of the forward current becomes considerable. There is a problem that such a forward current shortens the operable time of the portable communication device using the battery. Accordingly, the present invention provides a technique capable of reducing the power consumed when the diode switch is in the on state, suppressing the power consumption, and in particular, extending the operable time of the wireless communication device using the battery. It is done for the purpose of. According to a first aspect of the present invention, there is provided a wireless communication apparatus in which a plurality of filters are selectively switched for use. A plurality of sets of diode switches, an application unit for applying a forward voltage to any one of the plurality of diode switches, and one set of on states where the forward voltage is applied. Control means for controlling the forward current flowing through the diode switch to a suppressed state or a non-suppressed state, and when it is desired to reduce the power consumption of the wireless communication device, the forward current flowing through the diode switch is controlled by the control means. It was configured to suppress. According to the first aspect of the present invention, in a wireless communication device that uses a plurality of filters by selectively switching, the order in which a plurality of sets of diode switches for selectively switching the plurality of filters flow. By suppressing the direction current, the power consumption in the diode switch is reduced.
Usually, when the battery is driven, the operation is often performed outdoors, and in such a case, the operation environment is often not established such that a large antenna cannot be used. In such an operation environment, low power consumption performance is regarded as more important than reception performance such as IMD. Therefore, as in the present invention, it is preferable to improve the low current consumption performance by suppressing the current flowing through the diode switch depending on the operation state, the operation state, or the user's will. A radio communication device according to the present invention will be described below in detail with reference to the drawings showing an embodiment. FIG. 1 is a block diagram of an embodiment of a wireless communication device according to the present invention. The received signal input via the antenna circuit 51 is transmitted to the band-pass filter 1 and the high-frequency amplifier circuit.
The signal is supplied to the mixing circuit 54 via the control circuit 52. In the mixing circuit 54, the signal is mixed with the local oscillation frequency output from the local oscillation circuit 55 and input to the band-pass filter 53. The signal passed through the band-pass filter 53 is an intermediate frequency amplifier
The signals are processed by circuits such as a detection circuit 57, a detection circuit 57, and a low-frequency circuit 58, and output from a speaker or an earphone. Note that this wireless communication device has a battery to enable portable operation.
It has 59. The band-pass filter section 1 includes band-pass filters 11, 12, and 13 having different characteristics, and a switching circuit 21, which includes diode switches provided on the input side and the output side of each of the band-pass filters. 22,23. Reference numeral 3 denotes application means for selectively applying a forward voltage to each of the switching circuits, and reference numeral 4 denotes a state in which a forward current to the selected switching circuit via the application means 3 is suppressed or not suppressed. Control means for controlling any of the above. The switching circuit 21 includes a series circuit including an input diode D1, a coil L1 and a resistor R5 for grounding the cathode of the diode D1, and a coil L2 and a resistor R1 for connecting the anode of the diode D1 to the anode. A control voltage application wiring W1 connected to the application means 3 through
A capacitor C1 for grounding a connection point between the coil L2 and the resistor R1. The diode D2 is similarly connected to the output side.
A coil L3 and a resistor R7 for grounding the cathode side of the diode D2, and a control voltage application wiring for connecting the anode side of the diode D2 to the application means 3 via a series circuit of a coil L4 and a resistor R2. W2 and a capacitor C2 for grounding a connection point between the coil L4 and the resistor R2. The control voltage application wiring W
1 and W2 can share a part. The switching circuit 21 is configured by the circuit around the diode D1 on the input side and the circuit around the diode D2 on the output side configured as described above. The control voltage application wiring W1
Is applied with a resistor R1, a coil L2,
Since a circuit including the diode D1, the coil L1, and the resistor R5 is formed and a forward voltage is applied to the diode D1, the diode D1 is turned on, and the input high-frequency signal is input to the band-pass filter 11. You. In a state in which no control voltage is applied to the control voltage application wiring W1, no forward voltage is applied to the diode D1. Therefore, the diode D1 is turned off and an input high-frequency signal is cut off and is not input to the bandpass filter 11. . Note that the output side diode D2 is also controlled to the on state and the off state in the same manner as described above, so that the high frequency signal output from the bandpass filter 11 is controlled to pass and cut off. The switching circuits 22 and 23 have the same configuration as the switching circuit 21. Similarly, diodes D3, D4, D5,
D6 is included. The control voltage application wires to the switching circuit 22 are W3 and W4, and the control voltage application wires to the switching circuit 23 are W5 and W6. When the selection command signal for selecting the band-pass filter is input, the application means 3 applies a control voltage for switching only to the control voltage application wiring to the switching circuit specified by the selection command signal, and outputs the applied voltage. I do. The application means 3 is composed of a transistor array having a plurality of transistor elements. The selection command signal is input to the base side of each transistor element, and the control output from the control means 4 is applied to the collector side of each transistor element. A voltage is applied, and the control voltage application wiring is connected to the emitter side of each transistor element. In the above configuration, for example, when a selection command signal for selecting the bandpass filter 11 is input, the control voltage is applied and output only to the control voltage control wires W1 and W2. The control means 4 switches the magnitude of a current-limiting resistance value, which is provided in series with a supply line for a control voltage output to each switching circuit via the applying means 3, in a first direction. A resistor R3, a second resistor R4, and a transistor T for switching between a state in which the second resistor R4 is connected in parallel to the first resistor R3 and a state in which the second resistor R4 is separated from the first resistor R3;
1. In the initial state, which is a normal mode, the power saving command signal is not output, so that the transistor T1 is turned on, and the first resistor R3 and the second resistor R4 are connected in parallel. State. Therefore, the combined resistance value due to the parallel connection is reduced, and the current flowing through the supply line of the control voltage to the applying means 3 is in the non-suppressed state. Then, when the power saving mode switch PS is pressed and a power saving command signal is input to the transistor T1 via the buffer B, the transistor T1 switches from the on state to the off state. Therefore, the second resistor R4 connected in parallel with the first resistor R3
Is disconnected from the first resistor R3, so that the current flowing through the control voltage supply line to the application unit 3 is suppressed. Therefore, the diode switch D1,
The power consumption in D2 is suppressed. The power-saving mode switch PS has a toggle operation, and is alternately switched between a power-saving mode and a normal mode each time the switch is pressed. FIG. 1 referred to in the above description exemplifies a system in which the current flowing through the diode switch is controlled on the supply side. As shown in FIG. 2, the current flowing through the diode switch is controlled on the ground side. A control method may be used. In FIG. 2, a resistor R6 connected to a connection point between the coil L1 and the resistor R5 is configured to be switched between a state in which the resistor R5 is connected in parallel to the resistor R5 and grounded by a transistor T2 and a state in which the resistor R5 is separated. Have been. A resistor R8 connected to a connection point between the coil L3 and the resistor R7
Is configured to switch between a state of being connected in parallel to the resistor R7 by the transistor T3 and grounded and a state of being separated. In the case of FIG. 2, the control means is constituted by the resistors R5, R6, R7, R8 and the transistors T2, T3. In the initial state, which is a normal mode, the power saving command signal is not output, so that the transistors T2 and T3 are in the on state, and the resistors R5 and R6 and the resistors R5 and R6 are connected to each other. R7 and resistor R8
Is a parallel connection state. Therefore, the combined resistance value due to the parallel connection is reduced, and the current flowing through the coils L1 and L3 is in an unsuppressed state. And the power saving mode switch PS
Is pressed, the power saving command signal is output from the transistor T2,
When input to T3, the transistors T2 and T3 switch from the on state to the off state. Therefore, the resistor R6, which has been connected in parallel with the resistor R5, is disconnected from the resistor R5, so that the current flowing through the coils L1, L3 is reduced. Therefore, power consumption in the diode switches D1 and D2 is suppressed. The power saving command signal can be output not only by manual operation of the power saving mode switch PS but also automatically by the operation state. According to the first aspect of the present invention, the power consumption can be reduced by controlling the forward current flowing through the diode switch for switching the band-pass filter to a suppressed state. It is possible to operate the super heterodyne wireless communication device for a long time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of an embodiment of a wireless communication device according to the present invention. FIG. 2 is a block diagram of a main part of another embodiment. FIG. 3 is a block diagram of a conventional band-pass filter switching circuit using a diode switch. [Description of Signs] 1 Band-pass filter sections 11, 12, 13 Band-pass filters 21, 22, 23 Switching circuits D1, D2, D3, D4, D5, D6 using diode switches Diode 3 Application means 4 Control means 59 Battery

Claims (1)

Claims: 1. A wireless communication device for selectively switching a plurality of filters for use, the plurality of sets of diode switches for selectively switching the plurality of filters, and the plurality of diode switches. Applying means for applying a forward voltage to any one set of the diode switches; and suppressing or non-suppressing the forward current flowing through any one set of the diode switches to which the forward voltage is applied and turned on. Control means for controlling the state of the wireless communication apparatus, and when it is desired to reduce the power consumption of the wireless communication apparatus, the control means suppresses the forward current flowing through the diode switch. .