JP2000174555A - Voltage controlled oscillator of frequency band switching type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small sized frequency band switching type VCO at a low cost with a simple circuit configuration by adopting a configuration that a common VCO 5 whose oscillating frequency is made stable by a PLL is used to have provision for two frequency bands that are largely different. SOLUTION: The voltage controlled oscillator is provided with an oscillating frequency selection circuit including a resonance line 19, a tuning varactor diode 20 coupled with the resonance line 19, and a frequency band changeover circuit 11, a single VCO 5 whose oscillated frequency is made stable by a PLL, a 1st changeover switch 121 connected to an output side of the VCO 5 and which outputs selectively an oscillated signal with a fundamental oscillating frequency, and a 2nd changeover switch 122 through which the oscillated signal with the fundamental oscillating frequency is fed to a parametric frequency divider 3 and through which a frequency division signal of the oscillated signal with the fundamental oscillating frequency is outputted from the parametric frequency divider 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency band switching type voltage controlled oscillator, and more particularly to a method of selectively extracting signals in two frequency bands whose band frequencies differ by more than twice by one voltage controlled oscillator. The present invention relates to an enabled frequency band switching type voltage controlled oscillator.

[0002]

2. Description of the Related Art Generally, a phase control loop (PLL, hereinafter referred to as PLL) includes a voltage controlled oscillator (VCO, hereinafter referred to as VCO) for outputting an oscillation signal,
A phase comparator that compares the phase of the oscillation signal of the VCO with the reference frequency signal and generates a phase error signal indicating the phase difference between the signals, and an unnecessary frequency included in the phase error signal that receives the phase error signal. A PLL filter for removing the component, and works to control the frequency of the oscillation signal of the VCO by the phase error signal output from the PLL filter.

By the way, PLLs are used in many electric devices such as wireless devices.
In a VCO configuration means in which two PLLs in which the frequency of a local oscillation signal output from the device is nearly doubled are incorporated in one electric device such as a radio, the two PLLs are often used separately. Prepared and prepared two PL
L is incorporated in one electric device so that oscillation signals of two PLLs are selectively supplied to a utilization circuit unit.

FIG. 3 is a block diagram showing an essential configuration of an example of the known VCO forming means.

[0005] As shown in FIG.
The constituent means include a high frequency band PLL 31H, a low frequency band PLL 31L, a switching circuit 32, an oscillation signal output terminal 33, a PLL 31H side reference frequency signal supply terminal 34H, and a PLL 31L side reference frequency signal supply terminal 34L. It consists of In this case, the high frequency band PLL 31H includes the VCO 35H and the phase comparator 36.
H, and a PLL filter 37H. The low frequency band PLL 31L includes a VCO 35L and a phase comparator 3H.
6L and a PLL filter 37L. In the high frequency band PLL 31H, the components 35H, 36H, and 37H are connected as shown in FIG. 3, and in the low frequency band PLL 31L, the components 35L, 36L, and 37L are connected in FIG. Connected as shown. Also, PLL 31 for high frequency band
H, PLL 31L for low frequency band, switching circuit 32,
The oscillation signal output terminal 33 is connected as shown in FIG.

FIG. 4 shows the VCO shown in FIG.
Switching circuit 32, VCO 35H, V
It is a circuit diagram showing an example of the internal configuration of CO35L.

As shown in FIG. 4, the VCO structuring means includes a band switching signal supply terminal 46 and a power supply terminal 47, in addition to the switching circuit 32, the VCO 35H and the VCO 35L. The switching circuit 32 includes two switching diodes 38 ₁ and 38 ₂ and two transmission line type inductors 39 ₁ and 39 ₂ . P for high frequency band
The LL31H includes a resonance line 40H, a varactor diode 41H, a shunt capacitor 42H, two cascade-connected transistors 43 ₁ H and 43 ₂ H, a transmission line type inductor 44H, and a tuning voltage supply terminal 45H. I have. Similarly, the low frequency band PLL 31L includes a resonance line 40L, a varactor diode 41L, a shunt capacitor 42L, two cascade connection transistors 43 ₁ L and 43 ₂ L, and a transmission line type inductor 44L.
And a tuning voltage supply terminal 45L.

In the switching circuit 32, two switching diodes 38 ₁ and 38 ₂ and two transmission line type inductors 39 ₁ and 39 ₂ are connected as shown in FIG. In the VCO 35H, the resonance line 4
0H, a varactor diode 41H, a shunt capacitor 42H, and two cascaded transistors 43H.
₁ H, 43 ₂ H, a transmission line type inductor 44H, and a tuning voltage supply terminal 45H are connected as shown in FIG. 4, and similarly, in the VCO 35L, the resonance line 40
L, the varactor diode 41L, and the shunt capacitor 4
2L and two cascaded transistors 43 ₁ L,
43 and ₂ L, and the transmission line inductors 44L, are connected as shown to the tuning voltage supply terminal 45L Togazu 4.

In this case, the resonance line 40H, the varactor diode 41H, and the shunt capacitor 4 in the VCO 35H
2H constitutes an oscillation frequency selection circuit, and VCO3
Resonant line 40L and varactor diode 41 in 5L
L and the shunt capacitor 42L constitute an oscillation frequency selection circuit.

[0010] The VCO structuring means according to the above-mentioned configuration is schematically described
It works as follows.

In the high frequency band PLL 31H, the VCO 35H generates an oscillation signal of, for example, a frequency in the 1700 MHz band. The oscillation signal of the VCO 35H is supplied to the phase comparator 36H via the reference frequency signal supply terminal 34H. The phase is compared with the obtained reference frequency signal, and a phase error component obtained by the phase comparison is output from the phase comparator 36H and supplied to the PLL filter 37H. The PLL filter 37H removes an unnecessary frequency component from the phase error component, and the phase error component from which the unnecessary frequency component has been removed is supplied to the VCO 35H. VCO35H
Is frequency-controlled by the supplied phase error component such that the oscillation signal matches a predetermined frequency. At this time, V
A tuning voltage is supplied to the varactor diode 41H via the tuning voltage supply terminal 45H, and the capacitance value of the varactor diode 41H is adjusted by the tuning voltage.

On the other hand, in the low frequency band PLL 31L, the VCO 35L generates an oscillation signal of, for example, an 800 MHz band frequency. The oscillation signal of the VCO 35L is supplied to the phase comparator 36L via the reference frequency signal supply terminal 34L. The phase is compared with the supplied reference frequency signal, and a phase error component obtained by the phase comparison is output from the phase comparator 36L and supplied to the PLL filter 37L. The PLL filter 37L removes an unnecessary frequency component from the phase error component, and the phase error component from which the unnecessary frequency component has been removed is supplied to the VCO 35L. VCO35L
Is frequency-controlled by the supplied phase error component such that the oscillation signal matches a predetermined frequency. At this time, V
A tuning voltage is supplied to the varactor diode 41L via the tuning voltage supply terminal 45L, and the capacitance value of the varactor diode 41L is adjusted by the tuning voltage.

When the switching circuit 32 supplies the oscillation signal output from the VCO 35H to the oscillation signal output terminal 33, a positive band switching voltage is supplied through a band switching signal supply terminal 46. By 2
The diodes 38 ₁ and 38 ₂ are turned on. Therefore, an oscillation signal outputted from the VCO35H an oscillation through a diode 38 ₁ which is turned on the signal output terminal 33
And supplied from an oscillation signal output terminal 33 to an external use circuit (not shown). At this time, VCO3
Oscillation signal output from 5L flows to the ground point via the diode 38 ₂ which are turned on, the oscillation signal output terminal 3
Not supplied to 3.

On the other hand, when the oscillation signal output from the VCO 35L is supplied to the oscillation signal output terminal 33, a band switching voltage of the ground voltage is supplied through the band switching signal supply terminal 46, and the band switching voltage of the ground voltage is supplied. As a result, the two diodes 38 ₁ and 38 ₂ are turned off. Therefore, an oscillation signal outputted from the VCO35L may not flow to ground through diode 38 ₂ which are turned off, so also does not flow through the diode 38 ₁ is off, the direct oscillation signal output terminal 33 The signal is supplied from the oscillation signal output terminal 33 to an external use circuit (not shown). At this time, the oscillation signal output from the VCO 35L is turned off by the diode 38 _1.
And is not supplied to the oscillation signal output terminal 33.

As described above, in the known VCO constituting means, the oscillation signal of the VCO 35H and the oscillation signal of the VCO 35L are selectively supplied to the oscillation signal output terminal 33.

[0016]

As shown in FIGS. 3 and 4, the known VCO structuring means includes a PLL 3 for a high frequency band including an independent VCO 35H.
1H and P for low frequency band including VCO 35L
Since the LL31L is used, two PLLs 31H, 3
The 1 L component becomes complicated in terms of circuitry, and the overall structure of the VCO component increases, and the manufacturing cost increases.

The present invention has been made in view of such a technical background, and an object of the present invention is to use a common VCO frequency-stabilized by a PLL for two widely separated frequency bands. And a simple and low-cost frequency band switching type V
To provide CO.

[0018]

To achieve the above object, a frequency band switching type VCO according to the present invention comprises a PLL.
A first switch for selectively outputting an oscillation signal of the basic oscillation frequency to an output side of a common VCO whose oscillation frequency is stabilized by the oscillator, and selectively supplying the oscillation signal of the basic oscillation frequency to a parametric frequency divider And means connected to a second switch for outputting a frequency-divided signal from the parametric frequency divider.

According to the above means, when an oscillation signal of the fundamental oscillation frequency (high frequency band) is output from the VCO, the second switch is turned off and the first switch is turned on to output the fundamental oscillation frequency. The oscillation signal is output through the first switch that is turned on.
When outputting the oscillation signal of the division frequency (low frequency band) of the basic oscillation frequency from the CO, the first changeover switch is turned off and the second changeover switch is turned on to turn on the oscillation signal of the basic oscillation frequency. Is supplied to the parametric divider through the second selector switch, and the parametric divider outputs an oscillation signal obtained by dividing the fundamental oscillation frequency. Therefore, the common VCO whose frequency is stabilized by the PLL is provided. , It is possible to selectively output oscillation signals in the high frequency band and the low frequency band.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an embodiment of the present invention, a frequency band switching type VCO has a resonance line, a varactor diode coupled to the resonance line, and an oscillation frequency selection circuit including a frequency band switching circuit. A single voltage-controlled oscillator whose oscillation frequency is stabilized by a control loop, a first switch connected to the output side of the voltage-controlled oscillator for selectively outputting an oscillation signal of the basic oscillation frequency, and a A second switch for selectively outputting a frequency-divided signal obtained by parametrically dividing the oscillation signal is provided.

In a preferred example of the embodiment of the present invention, the frequency band switching type VCO includes a diode that performs parametric frequency division and a resonance circuit that resonates at a frequency that is about half the fundamental oscillation frequency. This is performed by a parametric frequency divider.

In a specific example of the embodiment of the present invention, the frequency band switching type VCO is such that the oscillation signal of the fundamental oscillation frequency is composed of a signal of the 1700 MHz band, and the divided signal obtained by parametric frequency division is composed of the signal of the 800 MHz band. It is.

According to these embodiments of the present invention, V
A common VCO frequency-stabilized by a PLL for a high frequency band and a low frequency band is used as CO, and a first changeover switch, a second changeover switch, and a parametric frequency divider are provided on the output side of the VCO. When the slave circuits are connected to each other and an oscillation signal of the fundamental oscillation frequency (high frequency band) is output from the VCO,
The second changeover switch is turned off and the first changeover switch is turned on so that the oscillation signal of the basic oscillation frequency is output through the turned on first changeover switch. In the case of outputting an oscillation signal of (low frequency band), the first switch is turned off and the second switch is turned on, and the parametric signal is passed through the second switch which turns on the oscillation signal of the fundamental oscillation frequency. Since the oscillation signal is supplied to the frequency divider and an oscillation signal obtained by dividing the fundamental oscillation frequency from the parametric frequency divider is output, only the common VCO whose frequency is stabilized by the PLL is used. It is possible to selectively output the oscillation signal of the frequency band, the configuration is simple, compact, and low-cost CO can be obtained.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a frequency band switching type voltage controlled oscillator (VCO) according to the present invention, and shows a schematic configuration of the frequency band switching type VCO.

As shown in FIG. 1, the frequency band switching type VCO of this embodiment has a phase control loop (PLL) 1
, A switching circuit 2, a parametric frequency divider 3, a high frequency band oscillation signal output terminal 4H, and a low frequency band oscillation signal output terminal 4L. In this case, P
LL1 includes a VCO 5, a phase comparator 6, a PLL filter 7, and a reference frequency signal supply terminal 8.

In the PLL 1, the VCO 5 is
The output terminal is connected to the input terminal of the switching circuit 2 and the first input terminal of the phase comparator 6, and the input terminal is connected to the output terminal of the PLL filter 7. The phase comparator 6 has a second input terminal connected to the reference frequency signal supply terminal 8 and an output terminal connected to an input terminal of the PLL filter 7. The switching circuit 2 has a first output terminal connected to the high frequency band oscillation signal output terminal 4H, and a second output terminal connected to an input terminal of the parametric frequency divider 3.
The output end of the parametric frequency divider 3 is connected to the low frequency band oscillation signal output terminal 4L.

FIG. 2 is a circuit diagram showing an example of a specific configuration of the switching circuit 2, the parametric frequency divider 3, and the VCO 5 in the frequency band switching type VCO shown in FIG.

As shown in FIG. 2, the switching circuit 2 includes a first switching diode (first switching switch) 12 _1.
And a second switching diode (second switch)
12 _2, the first inductor 13 _1, the second inductor 1
3 _2, and the third inductor 13 _3, a fourth inductor 13
_4, a fifth inductor 13 _5, a first switching voltage supply terminal 14 _1, a second switching voltage supply terminal 14 _2, which is a third switching voltage supply terminal 14 _3.

The parametric frequency divider 3 includes a PIN (or Schottky) diode 15 for performing a parametric operation, a transmission line type inductor 16 and a capacitor 17.
And a resistor 18. In this case, the inductance value of the transmission line type inductor 16 and the capacitance value of the capacitor 17 are selected so as to resonate in series at the frequency of the low frequency band.

The VCO 5 has a band switching voltage supply terminal 9
, A frequency band switching circuit 11, a resonance line 19, a varactor diode 20, and an oscillation first transistor 2.
1 _1, a second transistor 21 ₂ for oscillation, ₁ and the first shunt capacitor 22, a transmission wound inductor 24, and a tuning voltage supply terminal 25. In this case, the frequency band switching circuit 11 includes a second shunt capacitor 22 _2, a switching transistor 23. The resonance line 19, the varactor diode 20, the first shunt capacitor 22 ₁ , and the second shunt capacitor 22 ₂ together constitute an oscillation frequency selection circuit.

[0032] Then, in the switching circuit 2, a first switching diode 12 ₁ has an anode connected to one end of a fourth inductor 13 _4, a cathode connected to the output terminal of the VCO 5. The second switching diode 12 _2,
The anode is connected to the output terminal of the VCO 5, a cathode connected to the second inductor 13 ₂ at one end. The first inductor 13 ₁ is connected at one end to the output end of the VCO 5, the other end connected to the first switching voltage supply terminal 14 _1. The second inductor 13 ₂ and the other end connected to the input of the parametric frequency divider 3 through the output terminal of the switching circuit 2. The third inductor 13 ₃ has one end connected to the input of the parametric frequency divider 3 through the output terminal of the switching circuit 2, the other end a second
It is connected to the switching voltage supply terminal 14 _2. The fourth inductor 13 _4, the other end the high-frequency band oscillation signal output terminal 4
Connected to H. Fifth inductor 13 ₅ has one end connected to the high frequency band oscillation signal output terminal 4H, the other end connected to a third switching voltage supply terminal 14 _3.

In the parametric frequency divider 3,
The anode of the PIN diode 15 performing the parametric operation is connected to the input terminal of the parametric frequency divider 3,
The cathode is connected to the low frequency band oscillation signal output terminal 4L. The transmission line inductor 16 has one end connected to one end of the capacitor 17 and the other end connected to the low frequency band oscillation signal output terminal 4L. The other end of the capacitor 17 is connected to the input end of the parametric frequency divider 3. The resistor 18 has one end connected to the input end of the parametric frequency divider 3 and the other end grounded.

Further, in the VCO 5, the resonance line 19
Has one end connected to the first shunt capacitor 22 ₁ at one end and the other end connected to the first transistor 21 ₁ of the base and a second shunt capacitor 22 _{and second} end oscillation. The varactor diode 20 has a cathode connected to the first shunt capacitor 22.
₁ and one end of the transmission line type inductor 24,
The anode is connected to ground. Transmission line type inductor 24
Has the other end connected to the tuning voltage supply terminal 25. The first transistor 21 ₁ for oscillation has a collector connected to the second transistor 21 ₂ of the emitter oscillation and grounded emitter connected via a resistor (no reference numeral). The second transistor 21 ₂ oscillation has a collector connected to the output terminal of the VCO 5, a base connected to the first transistor 21 ₁ of emitter oscillation via a capacitor (no reference numeral). The switching transistor 23 has a collector connected to the second shunt capacitor 22 ₂ at the other end, a base connected to the band switching voltage supply terminal 9, and an emitter connected to ground.

The VCO 5 has an inductance value of the resonance line 19 constituting the resonance frequency selection circuit, a capacitance value of the varactor diode 20, a first shunt capacitor 22
By appropriately setting the capacitance values of the _first and second shunt capacitors 22 ₂ , the frequency band switching circuit 11
When the switching transistor 23 is turned on, the high frequency band oscillation signal, 1700 MHz in this embodiment,
It is set to output a z-band oscillation signal. The tuned voltage supplied to the varactor diode 20 causes the oscillation signal in the 1700 MHz band to be about 30 MHz.
The frequency shift of the oscillation signal is performed within the range of
By turning off 2, the oscillation signal of the 1700 MHz band is shifted in frequency to the oscillation signal of the 1600 MHz band.

Here, the frequency band switching type V of this embodiment is used.
The operation of the CO will be described as follows.

In the PLL 1, the oscillation signal output from the VCO 5 is compared in phase with the reference frequency signal supplied through the reference frequency signal supply terminal 8 in the phase comparator 6, and a phase error component is output from the phase comparator 6. . This phase error component is supplied to the VCO 5 after unnecessary frequency components have been removed by the PLL filter 4, and the VCO 5
Is controlled so that the oscillating signal of matches the preset oscillating frequency.

When the frequency band switching type VCO is switched to generate a high frequency band oscillation signal, a positive band switching voltage is supplied to the band switching voltage supply terminal 9 and the switching transistor 23 is turned on. becomes, the ₂ second shunt capacitor 22 is inserted and connected to the resonance frequency selection circuit, the first switching voltage supply terminal 14 ₁
If between the third switching voltage supply terminal 14 _3, together with the third switching voltage supply terminal 14 ₃ side becomes positive switching voltage is supplied also from the first switching voltage supply terminal 14 ₁ side, a first switching voltage supply between the terminals 14 ₁ and ₂ second switching voltage supply terminal 14, the switching voltage the second switching voltage supply terminal 14 ₂ side is more positive than the first switching voltage supply terminal 14 ₁ side is supplied, the first
Switching diode 12 ₁ is turned on, the second switching diode 12 ₂ is turned off. At this time, V
CO5 generates an oscillation signal of 1700 MHz band, and VCO
Oscillation signal 5 is supplied to the high frequency band oscillation signal output terminal 4H through the first switching diode 12 ₁ in the ON state, the high frequency band oscillation signal output terminal 4
An oscillation signal in the 1700 MHz band is extracted from H. On the other hand, the oscillation signal of VCO5 is blocked by the second switching diode 12 ₂ in the off state, without being supplied to the succeeding parametric frequency divider 3, whatever signal from the low frequency band oscillation signal output terminal 4L Is not output.

Next, when the frequency band switching type VCO is switched to generate the low frequency band oscillation frequency, the band switching voltage of the ground voltage is supplied to the band switching voltage supply terminal 9 and the switching transistor 23 is turned off. It turned to the second shunt capacitor 22 ₂ is not connected to the resonant frequency selection circuit, also between the first and switching voltage supply terminal 14 ₁ and the second switching voltage supply terminal 14 _2, first
The switching voltage supply terminal 14 ₁ is connected to the second switching voltage supply terminal 14
With positive with switching voltages than ₂ side is supplied, the first switching voltage supply terminal 14 ₁ and the third switching voltage supply terminal 14
Between the _3, the first switching voltage supply terminal 14 ₁ side is supplied becomes positive switching voltage than the third switching voltage supply terminal 14 ₃ side, the second switching diode 12 ₂ is turned on,
The first switching diode 12 ₁ is turned off. At this time, VCO 5 generates an oscillation signal of 1600MHz band, the oscillation signal is supplied to a parametric frequency divider 3 through the second switching diode 12 ₂ in the ON state. The parametric frequency divider 3 outputs an oscillation signal of PIN
When supplied to the diode 15, the PIN diode 15
Causes a pumping phenomenon due to this oscillation signal, and an oscillation signal having an integer fraction of the supplied oscillation signal frequency is generated. At this time, the resonance of the series circuit of the transmission line type inductor 16 and the capacitor 17 connected in parallel to the PIN diode 15 selects a frequency of の of the supplied oscillation signal frequency and outputs it from the parametric frequency divider 3. You. That is, the parametric frequency divider 3 frequency-divides the supplied oscillation signal into a half frequency, converts the frequency to an 800 MHz band oscillation signal, and supplies the 800 MHz band oscillation signal to the low frequency band oscillation signal output terminal 4L. An oscillation signal in the 800 MHz band is extracted from the band frequency band oscillation signal output terminal 4L. In contrast, the oscillation signal of VCO5 since blocked by the first switching diode 12 ₁ is turned off, no output signal of what such a high frequency band oscillation signal output terminal 4H.

As described above, according to the frequency band switching type VCO of the present embodiment, the oscillation signals of the two frequency bands, that is, the high frequency band and the low frequency band, that is, the oscillation signal of the 1700 MHz band are separated from each other. 800M
When extracting the oscillation signal in the Hz band, a common VCO 5 frequency-stabilized by the PLL 1 is used, and the oscillation signal of the VCO 5 is directly output to extract the high frequency band oscillation signal, and the oscillation signal of the VCO 5 is extracted. After parametric frequency division by the parametric frequency divider 3, the frequency-divided low frequency band oscillation signal is taken out, so that a simple and compact, low-cost frequency band switching type VCO can be obtained. .

In this embodiment, the high frequency band is 1700 MHz and the low frequency band is 800 MHz.
Although the description has been given by taking the example of the MHz band, the high frequency band and the low frequency band according to the present invention are not limited to the above example, and the ratio between the high frequency band and the low frequency band is 1 /. The present invention can be similarly applied to the case where it is close to 2 and slightly shifted from 1/2.

Further, in this embodiment, an example has been described in which the circuit configuration shown in FIG. 2 is used as the parametric frequency divider 3, but the parametric frequency divider according to the present invention has such a circuit configuration. It is needless to say that a parametric frequency divider having another circuit configuration, for example, a parametric frequency divider disclosed in Japanese Utility Model Publication No. 7-22897 may be used.

[0043]

As described above, according to the present invention, a common VCO frequency-stabilized by the PLL is used for the high frequency band and the low frequency band, and this VC
When the first switching switch, the second switching switch, and the subordinate circuits of the parametric frequency divider are connected to the output side of O, respectively, and when the oscillation signal of the fundamental oscillation frequency (high frequency band) is output from the VCO, , The second switch is turned off, the first switch is turned on, and the oscillation signal of the basic oscillation frequency is output through the first switch in the on state. When outputting an oscillation signal of a low frequency band), the first switch is turned off and the second switch is turned on, and the oscillation signal of the fundamental oscillation frequency is parametrically passed through the second switch which is on. Since the oscillation signal is supplied to the frequency divider and the parametric frequency divider outputs the oscillation signal obtained by dividing the fundamental oscillation frequency, the common VCO
, It is possible to selectively output the oscillation signals in the high frequency band and the low frequency band, and it is possible to obtain a simple, compact, low-cost frequency band switching type VCO. There is.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a frequency band switching type voltage controlled oscillator (VCO) according to the present invention.

FIG. 2 is a circuit diagram showing an example of a specific configuration of a switching circuit, a parametric frequency divider, and a VCO in the frequency band switching type VCO shown in FIG.

FIG. 3 is a block diagram illustrating a main configuration of an example of a known VCO configuration unit.

FIG. 4 is a circuit diagram illustrating an example of the internal configuration of a switching circuit and two VCOs used in the VCO configuration unit illustrated in FIG. 3;

[Explanation of symbols]

Reference Signs List 1 phase control loop (PLL) 2 switching circuit 3 parametric frequency divider 4H high frequency band oscillation signal output terminal 4L low frequency band oscillation signal output terminal 5 voltage controlled oscillator (VCO) 6 phase comparator 7 PLL filter 8 reference frequency Signal supply terminal 9 Band switching voltage supply terminal 10 Power supply terminal 11 Frequency band switching circuit 12 ₁ First switching diode (first switching switch) 12 ₂ Second switching diode (second switching switch) 13 ₁ First inductor 13 _2nd 2 inductor 13 ₃ third inductor 13 ₄ fourth inductor 13 ₅ fifth inductor 14 ₁ first switching voltage supply terminal 14 ₂ second switching voltage supply terminal 14 ₃ third switching voltage supply terminal 15 PIN diode (or Schottky diode) 16 Transmission line type inductor 17 Capacitor 18 Resistor 19 Resonant line 20 Varactor diode 21 ₁ First transistor for oscillation 21 ₂ Second transistor for oscillation 22 ₁ First shunt capacitor 22 ₂ Second shunt capacitor 23 Switching transistor 24 Transmission line inductor 25 Tuning voltage supply terminal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J081 AA11 AA19 BB06 CC42 DD02 DD16 EE09 EE18 FF06 FF25 GG06 GG08 KK02 KK09 KK22 LL05 MM01 5J106 AA01 AA04 CC02 CC15 CC19 CC21 CC52 GG01 HH01 JJ01 KK38 LL

Claims (3)

[Claims] A single voltage-controlled oscillator having an oscillation frequency selection circuit including a resonance line, a varactor diode coupled to the resonance line, and a frequency band switching circuit, wherein the oscillation frequency is stabilized by a phase control loop; A first switch connected to an output side of the voltage controlled oscillator for selectively outputting an oscillation signal of a fundamental oscillation frequency, and selectively outputting a divided signal obtained by parametrically dividing the oscillation signal of the fundamental oscillation frequency. A frequency band switching type voltage controlled oscillator comprising a second changeover switch. 2. The parametric frequency divider according to claim 1, wherein the parametric frequency division is performed by a parametric frequency divider including a diode performing a parametric operation and a resonance circuit resonating at a frequency of about の of the fundamental oscillation frequency. The frequency band switching type voltage controlled oscillator according to claim 1. 3. The oscillation signal of the fundamental oscillation frequency is 170
3. The frequency band switching type voltage controlled oscillator according to claim 1, wherein the signal is a 0 MHz band signal and the parametric frequency-divided signal is an 800 MHz band signal.