JP2006253835A - Oscillation circuit module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oscillation circuit module the output level and the frequency load stability of which are enhanced by ensuring isolation between a collector and a base of a transistor of a signal output section. <P>SOLUTION: In the oscillation circuit module, an external power terminal VB2 to which a base bias circuit (R11, R12, R13) connected to a base of a buffer transistor Q12 of a first voltage-controlled oscillator VCO 1 is connected via a switch SW1 is different from an external power terminal VB1 to which a collector of the transistor Q12 is connected. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an oscillation circuit module that includes a plurality of oscillation circuits and outputs any one of the oscillation signals.

  A collector-grounded Colpitts-type voltage-controlled oscillator as shown in Patent Document 1 has been conventionally used. An example of the circuit configuration of this voltage controlled oscillator is shown in FIG.

  This voltage controlled oscillator includes a resonance circuit RS and an amplifier circuit AS. The amplifier circuit AS is composed of an amplifier stage circuit GS and a buffer stage circuit BS. The resonance circuit RS includes capacitors Ca, Cb, Cc, Cd, inductors La, Lb, and a variable capacitance diode VD. The amplification stage circuit GS includes a transistor Q1, capacitors C4, C6, C7, and C8 and resistors R2, R3, and R4, and amplifies the resonance signal of the resonance circuit RS. The buffer stage circuit BS includes a transistor Q2, an inductor L1, and a resistor R1, and inputs the signal amplified by the amplification stage circuit GS via the capacitor C6, and outputs from the collector of Q2 via the capacitor C2 to the output terminal P. More oscillation signals are output.

  The resistors R1, R2, and R3 constitute a base bias circuit for the transistors Q1 and Q2. A high frequency bypass capacitor C1 is connected to the external power supply terminal VB, and a matching capacitor C3 is connected to the collector of Q2.

  Although there is no clear description in Patent Document 1, when the oscillator is configured as one module, the power supply terminal and the output terminal function as external terminals included in the module itself.

Conventionally, in order to support two different frequency bands (frequency bands for dual terminals of GSM / DCS) using the voltage controlled oscillator having the above configuration, two voltage controlled oscillators are provided in a single module (package). A so-called dual VCO that is arranged and provided with a switch for each switch is also used. An example is shown in FIG.
Here, the first voltage-controlled oscillation circuit VCO1 and the second voltage-controlled oscillation circuit VCO2 have the same configuration in the circuit diagram, but circuit constants are set in order to obtain a desired oscillation frequency. External power supply terminals VB1 and VB2, output terminals P1 and P2, and switches SW1 and SW2 are provided in the respective voltage control oscillation circuits VCO1 and VCO2. One of them is configured to operate. In the example shown in FIG. 6, the control voltage for the resonance circuit RS1 of the first voltage controlled oscillation circuit VCO1 and the control voltage for the resonance circuit RS2 of the second voltage controlled oscillation circuit VCO2 are supplied from a common control terminal VC. It is configured to do.

Thus, the base bias for the amplifying transistors Q11, Q21 and the buffer transistors Q12, Q22 is switched on / off of the two voltage controlled oscillation circuits VCO1, VCO2 without switching the power supply voltage supply from the external power supply terminals VB1, VB2. The reason for switching the circuits is to increase the switching speed.
JP 2001-185951 A

  In the circuit shown in FIG. 5, the transistor Q2 of the buffer stage circuit is desired to have good collector-base isolation since the input signal is the base terminal and the output is the collector terminal. However, in practice, sufficient isolation cannot be ensured. This is because, besides the collector-base of the transistor, there is a path through which the signal leaks in the path from the resistor R1 to the inductor L1 as a signal path. Although the inductor L1 is composed of a choke line, due to layout problems, the impedance cannot be sufficiently high, and the resistor R1 is often set to a relatively low resistance of several tens to several hundreds Ω. It is.

  Due to the effect of the elements added to the outside of these transistors, sufficient isolation between the collector and base cannot be ensured, and the characteristics of the oscillation circuit include a decrease in output level and frequency load stability (external load impedance There is a problem that the degree of fluctuation of the output signal of the oscillation circuit with respect to fluctuations is deteriorated. As shown in FIG. 6, this is a problem that arises even when a plurality of oscillation circuits are provided in a single module and the oscillation circuits are selectively operated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an oscillation circuit module that solves the isolation problem and improves the reduction in output level and the deterioration in frequency load stability.

  In order to solve the above problems, the oscillation circuit module of the present invention is configured as follows.

  (1) A plurality of oscillation circuits each including a resonance circuit and an amplification circuit that amplifies a resonance signal of the resonance circuit and outputs the amplification signal to the outside together with individual external power supply terminals that apply a power supply voltage to each oscillation circuit. In the set oscillation circuit module, the amplification stage circuit of at least one oscillation circuit among the plurality of oscillation circuits includes a transistor having a current controlled terminal connected to a power source and a control terminal connected to the control terminal of the transistor An external power supply terminal to which the control terminal bias circuit is connected and an external power supply terminal to which the current controlled terminal is connected.

  (2) The amplification stage circuit includes, for example, an amplification stage circuit that amplifies a resonance signal of the resonance circuit, and a buffer stage circuit provided between the output section of the amplification stage circuit and the output section to the outside, The transistor is a transistor of the buffer stage circuit.

  (3) The amplification stage circuit and the buffer stage circuit are connected in cascade, for example, and are configured to supply the voltage or current of each current controlled terminal and control terminal from different external power supply terminals.

  (4) The transistor of the amplification stage circuit and the transistor of the buffer stage circuit are arranged in parallel to the power supply, and the voltage or current of each current controlled terminal and control terminal is supplied from another external power supply terminal. Configure.

  (1) An external power supply terminal to which a base bias circuit of a transistor in an amplification stage circuit of at least one oscillation circuit among a plurality of oscillation circuits is connected is different from an external power supply terminal to which a current controlled terminal of a transistor is connected As a result, the current controlled terminal of the transistor and the voltage or current of the control terminal are supplied from different external power supply terminals. First, go out of the module from the external power supply terminal to which the current controlled terminal of the transistor is connected, then enter the module again from another external power supply terminal via the wiring on the mounting board, and wrap around through the base bias circuit become. Since the wraparound path becomes longer in this way, it becomes difficult to wrap around and sufficient isolation between the current controlled terminal and the control terminal of the transistor can be secured. As a result, it is possible to improve the decrease in the output level and the deterioration of the frequency load stability, which are the conventional problems.

  (2) In an oscillation circuit in which an amplification stage circuit that amplifies a resonance signal of the resonance circuit and a buffer stage circuit between an output section of the amplification stage circuit and an output section to the outside, When the configuration of grounded collector (emitter output or base output) and the buffer stage circuit is configured to extract the output signal from the collector of the transistor), the above-described configuration is applied to the transistor of the buffer stage circuit. Since the wraparound path becomes long, sufficient isolation between the current controlled terminal and the control terminal of the transistor of the buffer stage circuit can be ensured. As a result, it is possible to improve output level reduction and frequency load stability deterioration.

  (3) The connection relationship between the transistor of the amplification stage circuit and the transistor of the buffer stage circuit may be a cascade connection or a parallel arrangement with respect to the power source, By configuring the control terminal voltage or current to be supplied from another external power supply terminal, sufficient isolation between the collector and base of the above-mentioned transistor can be secured, and the output level and frequency load stability are degraded. Can be improved.

The oscillation circuit module according to the first embodiment will be described with reference to FIG.
FIG. 1 is a circuit diagram of the oscillation circuit module 100. The oscillation circuit module 100 is roughly composed of a first voltage controlled oscillation circuit VCO1 and a second voltage controlled oscillation circuit VCO2. The configuration of each voltage controlled oscillation circuit VCO1, VCO2 is substantially the same as that shown in FIG. However, the switch SW1 is provided between the base bias circuit including the resistors R11, R12, and R13 of the first voltage controlled oscillation circuit VCO1 and the external power supply terminal VB2 of the second voltage controlled oscillation circuit VCO2. Further, a switch SW2 is provided between the base bias circuit including the resistors R21, R22, and R23 of the second voltage controlled oscillation circuit VCO2 and the external power supply terminal VB1 of the first voltage controlled oscillation circuit VCO1. The collector of the transistor Q12 of the first voltage controlled oscillation circuit VCO1 is connected to the external power supply terminal VB1, the base bias circuit of the first voltage controlled oscillation circuit VCO1 is connected to the external power supply terminal VB2, and the second voltage control. The collector of the transistor Q22 of the oscillation circuit VCO2 is connected to the external power supply terminal VB2, and the base bias circuit of the second voltage controlled oscillation circuit VCO2 is connected to the external power supply terminal VB1.

  Here, the bases of the transistors Q12 and Q22 correspond to the “control terminal” according to the present invention, and the collector corresponds to the “current controlled terminal” according to the present invention. The base bias circuit corresponds to a “control terminal bias circuit” according to the present invention.

  Thus, the external power supply terminal to which the base bias circuit is connected and the external power supply terminal to which the collectors of the transistors Q12 and Q22 of the buffer stage circuit are connected are different from each other. The external power supply terminals VB1 and VB2 are connection external terminals provided in the oscillation circuit module for connection to the mounting board. In FIG. 1, the switches SW1 and SW2 are represented by switch symbols. However, the switches SW1 and SW2 are actually configured by a switch circuit using active elements.

The operation of the circuit shown in FIG. 1 is as follows.
In FIG. 1, when the switch SW1 is turned on and the switch SW2 is turned off, an appropriate base bias current is supplied to the transistors Q11 and Q12 of the first voltage controlled oscillation circuit VCO1, and a resonance signal from the resonance circuit RS1 is generated. The signal is amplified by the transistor Q11 and output from the output terminal P1 through the buffer stage circuit of the transistor Q12. The oscillation frequency of the first voltage controlled oscillation circuit VCO1 is controlled by the voltage applied to the control terminal VC.

  In this state, for example, when a signal tries to pass between the collector and base of the transistor Q12, the signal from the collector of the transistor Q12 once goes out of the module through the inductor L1 and the external power supply terminal VB1, The module enters again from another external power supply terminal VB2 via the wiring of the mounting board and wraps around through the switch SW1 and the resistor R11. This wraparound path is long, and the collector-base of the transistor Q12 is sufficient between the collector and base. Secure isolation.

  Conversely, when the switch SW2 is turned on and the switch SW1 is turned off, an appropriate base bias current is supplied to the transistors Q21 and Q22 of the second voltage controlled oscillation circuit VCO2, and the resonance signal from the resonance circuit RS2 is changed to the transistor Q21. And output from the output terminal P2 via the buffer stage circuit of the transistor Q22. The oscillation frequency of the second voltage controlled oscillation circuit VCO2 is controlled by the voltage applied to the control terminal VC.

  In this state, when a signal is going to pass between the collector and base of the transistor Q22, the signal from the collector of the transistor Q22 once goes out of the module through the inductor L2 and the external power supply terminal VB2, and is mounted. The module enters again from another external power supply terminal VB1 through the wiring of the board and wraps around through the switch SW2 and the resistor R21. However, this wraparound path is long and the collector-base of the transistor Q22 is sufficient between the collector and base. Isolation can be secured.

  Since the external power supply terminals VB1 and VB2 are provided with high-frequency bypass capacitors C11 and C21, these two bypass capacitors exist in the wraparound path, thereby further suppressing signal wraparound. The

  With such a configuration, as shown in FIG. 6, there is no signal leakage in the path L1 → R11 and the path L2 → R21, and the collector-base isolation of the buffer transistors Q12 and Q22 is good. Become. As a result, the frequency load stability of how much the oscillation frequency changes with respect to the fluctuation of the external load is improved, and the output level is also reduced.

Next, an oscillation circuit module according to a second embodiment will be described with reference to FIG.
FIG. 2 is a circuit diagram of the oscillation circuit module 101. The difference from the oscillation circuit module 100 shown in FIG. 1 is that the base bias current of the first voltage controlled oscillation circuit VCO1 is made to flow through the choke inductor L2 of the second voltage controlled oscillation circuit VCO2. The base bias current of the second voltage controlled oscillator circuit is configured to flow through the choke inductor L1 of the first voltage controlled oscillator circuit VCO1.

  With such a configuration, a base current flows through the resistors R11 and R21 of the base bias circuit via the inductor L2 or L1 as a choke line, so that the impedance when the external power supply terminal is viewed from the transistor side is shown in FIG. Higher than the configuration shown. As a result, the collector-base isolation of the buffer transistors Q12 and Q22 can be further increased.

Next, an oscillation circuit module according to a third embodiment will be described with reference to FIG.
In the first and second embodiments, the transistor of the amplifier stage circuit and the transistor of the buffer stage circuit are connected in cascade, but in this third embodiment, the transistor of the amplifier stage circuit and the transistor of the buffer stage circuit are connected. It is arranged in parallel with the power supply so that each collector current and base current are supplied from separate external power supply terminals.

  The oscillation circuit module 103 includes a first voltage controlled oscillation circuit VCO1 and a second voltage controlled oscillation circuit VCO2. The first and second voltage controlled oscillation circuits VCO1 and VCO2 have the same configuration in the circuit diagram, but circuit constants are set to obtain a desired oscillation frequency.

  The first voltage controlled oscillation circuit VCO1 will be described as a representative. The transistor Q13 is an amplifying stage circuit transistor. A base bias circuit composed of resistors R15 and R16 is connected to the base of the transistor Q13, and the switch SW1 is connected from the external power supply terminal VB2. The base bias current is supplied through the. An inductor L13, which is a choke line, is connected between the external power supply terminal VB1 and the collector of the transistor Q13, and a resistor R17 is inserted between the emitter and ground.

  The first resonance circuit RS1 is connected to the base of the transistor Q13. The resonance frequency of the resonance circuit RS1 is controlled by applying a control voltage to the control terminal VC.

  A base bias circuit composed of resistors R18 and R19 is connected to the base of a transistor (buffer transistor) Q14 in the buffer stage circuit, and a base bias current is supplied from the external power supply terminal VB2 via the switch SW1. An inductor L14 serving as a choke line is connected between the collector of the buffer transistor Q14 and the external power supply terminal VB1. Further, a resistor R10 is inserted between the emitter and ground. The emitter of the amplifying transistor Q13 and the buffer transistor Q14 are connected via a capacitor C19. A capacitor C12 is connected between the collector of the buffer transistor Q14 and the output terminal P1, and an output signal is taken out from the output terminal P1 via the capacitor C12. A matching capacitor C13 is connected between the collector of the transistor Q14 and the ground.

The operation of the oscillation circuit module shown in FIG. 3 is as follows.
When the switch SW1 is on and the switch SW2 is off, a base bias current is supplied from the external power supply terminal VB2 to the transistors Q13 and Q14, whereby the first voltage controlled oscillation circuit VCO1 operates. The second voltage controlled oscillation circuit VCO2 does not oscillate because a predetermined base bias current is not supplied to its transistors Q23 and Q24.

  In this state, the signal leakage path from the collector to the base of the buffer transistor Q14 passes outside the module, so that sufficient isolation between the collector and base of the transistor Q14 can be ensured. As a result, the frequency load stability is improved and the output level is also reduced.

  Further, when the switch SW2 is in an on state and the switch SW1 is in an off state, a base bias current is supplied from the external power supply terminal VB1 to the transistors Q23 and Q24, whereby the second voltage controlled oscillation circuit VCO2 operates. The first voltage controlled oscillation circuit VCO1 does not oscillate because a predetermined base bias current is not supplied to its transistors Q13 and Q14.

  In this state, the signal leakage path from the collector to the base of the buffer transistor Q24 passes outside the module, so that sufficient isolation between the collector and the base of the transistor Q24 can be secured.

Next, an oscillation circuit module according to a fourth embodiment will be described with reference to FIG.
The difference from the oscillation circuit module shown in FIG. 3 is that the collector currents of the amplifying transistors Q13 and Q23 are supplied from the external power supply terminals VB1 and VB2 of the same voltage controlled oscillation circuits VCO1 and VCO2, respectively. The oscillator circuit module 104 shown in FIG. 4 supplies the collector current of the transistor Q13 of the first voltage controlled oscillator circuit VCO1 from the external power supply terminal VB2, and the collector current of the transistor Q23 of the second voltage controlled oscillator circuit VCO2 is supplied. The power is supplied from the first external power supply terminal VB1.

  In such a configuration, as in the case of the third embodiment, the collector-base isolation of the transistors Q14 and Q24 can be sufficiently secured, the frequency load stability is improved, and the output level is also lowered. Improved.

  In each of the above embodiments, a bipolar transistor having a control terminal as a “base” and a current controlled terminal as a “collector” is used as a transistor included in the oscillation circuit. A unipolar transistor (FET) having a “gate” and a current controlled terminal as a “drain” may be used. In this case, the control terminal bias circuit may be configured to apply a predetermined bias voltage to the gate.

1 is a circuit diagram illustrating a configuration of an oscillation circuit module according to a first embodiment. FIG. It is a circuit diagram which shows the structure of the oscillation circuit module which concerns on 2nd Embodiment. It is a circuit diagram which shows the structure of the oscillation circuit module which concerns on 3rd Embodiment. It is a circuit diagram which shows the structure of the oscillation circuit module which concerns on 4th Embodiment. It is a circuit diagram which shows the structure of the conventional voltage controlled oscillator. It is a circuit diagram which shows the structural example of the conventional oscillation circuit module.

Explanation of symbols

RS-resonant circuit AS-amplifier circuit GS-amplifier stage circuit BS-buffer stage circuit VCO-voltage controlled oscillator circuit 100,101,103,104-oscillator circuit module

Claims (4)

A plurality of oscillation circuits each including a resonance circuit and an amplification circuit that amplifies the resonance signal of the resonance circuit and outputs the amplification signal to the outside are provided together with individual external power supply terminals that apply a power supply voltage to each oscillation circuit. In the oscillation circuit module,
Among the plurality of oscillation circuits, at least one oscillation circuit includes a transistor having a current controlled terminal connected to a power source and a control terminal bias circuit connected to the control terminal of the transistor, and the control terminal bias circuit is connected An oscillation circuit module, wherein the external power supply terminal to be connected is different from the external power supply terminal to which the current controlled terminal is connected.   The amplification circuit includes an amplification stage circuit that amplifies a resonance signal of the resonance circuit, and a buffer stage circuit provided between an output unit of the amplification stage circuit and the output unit to the outside, and the transistor includes the buffer The oscillation circuit module according to claim 1, wherein the oscillation circuit module is a transistor of a stage circuit.   3. The oscillation circuit module according to claim 2, wherein the amplification stage circuit and the buffer stage circuit are cascade-connected, and the voltage or current of each current controlled terminal and control terminal is supplied from another external power supply terminal.   The transistor of the amplification stage circuit and the transistor of the buffer stage circuit are arranged in parallel to a power supply, and the voltage or current of each current controlled terminal and control terminal is supplied from another external power supply terminal. Item 3. The oscillation circuit module according to Item 2.

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