JP2007166005A - Synthesizer module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synthesizer module in which leakage of a reference signal to a voltage controlled oscillator 1 is eliminated by connecting a filter 4 for removing the reference signal between a ground pattern region 7 for PLL circuit and a wide area ground pattern 11. <P>SOLUTION: A voltage controlled oscillator 1 and a PLL circuit 2 are mounted, and a ground pattern region 6 for the voltage controlled oscillator and a ground pattern region 7 for the PLL circuit are formed on the upper surface of an insulating substrate 5, and a wide area ground pattern 11 is formed on the lower surface of the insulating substrate 5. Furthermore, a filter 4 for removing the reference signal of the PLL circuit is mounted and a ground pattern region 10 for the filter is formed on the upper surface of the insulating substrate 5, the filter 4 is connected between the ground pattern region 7 for the PLL circuit and the ground pattern region 10 for the filter, and the ground pattern region 10 for the filter is connected conductively with the wide area ground pattern 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a synthesizer module in which a voltage controlled oscillator and a PLL circuit are integrated, and in particular, a spurious frequency component leaking from the voltage controlled oscillator and the PLL circuit when the voltage controlled oscillator and the PLL circuit are integrated is a voltage controlled oscillator. The present invention relates to a synthesizer module provided with means for suppressing superimposition on the oscillation signal.

  Generally, a high-frequency transmission / reception device includes a voltage controlled oscillator that generates a clock signal and a PLL circuit that controls a clock frequency oscillated from the voltage controlled oscillator to a predetermined frequency. Such voltage-controlled oscillators and PLL circuits usually use an integrally configured synthesizer module in order to minimize the occupied portion when mounted.

  Here, FIG. 4 is a block diagram showing an example of a circuit configuration of a typical synthesizer module.

  As shown in FIG. 4, the synthesizer module includes a voltage controlled oscillator (VCO) 31 and a PLL circuit (PLL) 32, and the control terminal 31 (2) of the voltage controlled oscillator 31 is a control output of the PLL circuit 32. The ground terminal 31 (3) is connected to the ground pattern (not shown in FIG. 3) together with the ground terminal 32 (3) of the PLL circuit 32, and the output terminal 31 (1) is connected to the ground terminal 31 (1). A high frequency oscillation signal (RF) is output. Although not shown in FIG. 3, a reference frequency generator is used, and an output of the reference frequency generator is connected to the control input terminal 32 (2) of the PLL circuit 32. In this case, the PLL circuit 32 compares the frequency of the high-frequency oscillation signal output from the voltage-controlled oscillator 31 with the frequency of the reference frequency signal supplied from the reference frequency generator, and the frequency control voltage corresponding to the comparison result is obtained. The voltage is supplied from the control output terminal 32 (1) to the control terminal 31 (2) of the voltage controlled oscillator 31 and controlled by the frequency control voltage so that the oscillation frequency of the voltage controlled oscillator 31 becomes a predetermined frequency.

  The synthesizer module having such a configuration is simple in configuration, but the ground terminal 31 (3) of the voltage controlled oscillator 31 and the ground terminal 32 (3) of the PLL circuit 32 are connected to a common ground pattern. Therefore, the spurious frequency component may be supplied from the PLL circuit 32 to the voltage controlled oscillator 31 through a common ground pattern, and this spurious frequency component may be superimposed on the high frequency signal generated from the voltage controlled oscillator 31.

  In recent years, in order to reduce the size of high-frequency transmission / reception equipment, there has been a growing demand to configure a synthesizer module that is as small as possible, and to set the frequency of the high-frequency oscillation signal of the voltage-controlled oscillator to a higher value as the frequency band used increases. Yes. In this case, when the synthesizer module is mounted and configured in accordance with the demand for miniaturization of the synthesizer module and the demand for higher frequency of use frequency band, the voltage controlled oscillator and the PLL circuit are necessarily mounted in a considerably close state. There is a need. However, when the voltage controlled oscillator and the PLL circuit are arranged close to each other, mutual effects often occur between them, and as a result, the high frequency output from the voltage controlled oscillator as in the typical synthesizer module. A spurious frequency component is superimposed on the oscillation signal.

  In order to eliminate the influence of such spurious frequency components, a mounting structure has been proposed in which the grounding structure at the time of mounting is devised so that noise components output from one functional circuit group are not transmitted to other functional circuit groups. One of them is a mounting structure disclosed in Japanese Patent Application Laid-Open No. 2004-119598.

  FIG. 5 is a sectional view showing a transverse section of the mounting structure disclosed in Japanese Patent Application Laid-Open No. 2004-119598.

  As shown in FIG. 5, this mounting structure includes insulating substrates 41, 42 and 43 having a three-layer structure, and the uppermost insulating substrate 41 has four functional circuit groups 44A, 44B, 44C and 44D on the upper side thereof. And ground pattern regions 45A, 45B, 45C and 45D are formed, an intermediate ground pattern 46 is formed between the insulating substrates 41 and 42, a power supply pattern 47 is formed between the insulating substrates 42 and 43, and insulation is performed. A ground pattern 48 is formed on the lower side of the substrate 43. In this case, the intermediate ground pattern 46 and the ground pattern 48 are connected to the external ground point G, and the power supply pattern 4 is connected to the external power supply terminal Vcc.

  The four ground pattern regions 45A, 45B, 45C, and 45D are conductively connected to the intermediate ground pattern 46, and through through holes 49A, 49B, 49C, and 49D formed between the insulating substrates 42 and 43, respectively. The ground pattern 48 is conductively connected to form four functional circuit groups 44A, 44B, 44C and 44D. The power terminals of the four functional circuit groups 44A, 44B, 44C, and 44D are conductively connected to the power supply pattern 47 through through holes 50A, 50B, 50C, and 50D formed between the insulating substrates 41 and 42, respectively. These power supply paths are formed.

In this mounting structure having the above-described configuration, the ground pattern areas 45A, 45B, 45C, and 45D of the four functional circuit groups 44A, 44B, 44C, and 44D are conductively connected to the intermediate ground pattern 46 in a wide area, and the through hole 49A. 49B, 49C, and 49D, the ground pattern 48 is conductively connected. Even if there is a large current difference during operation between the four functional circuit groups 44A, 44B, 44C, and 44D, the ground pattern regions 45A, 45B, and 45C are connected. , 45D, no current flows between the four functional circuit groups 44A, 44B, 44C, 44D, and the ground level of the functional circuit groups 44C, 44D is stabilized. For example, the functional circuit groups 44C, 44D are voltage controlled oscillators. Even if the functional circuit groups 44A and 44B are PLL circuits, voltage controlled oscillation It is capable of reducing the jitter on the clock signal output from the.
JP 2004-119598 A

  In the mounting structure disclosed in Japanese Patent Application Laid-Open No. 2004-119598, the ground pattern areas 45A, 45B, 45C, and 45D of the four functional circuit groups 44A, 44B, 44C, and 44D are conductively connected by a wide-area intermediate ground pattern 46. Therefore, when one of the four functional circuit groups 44A, 44B, 44C, and 44D is a voltage-controlled oscillator and the other is a PLL circuit, the reference that is frequency-compared with the reference frequency signal A clock signal in which a spurious frequency signal component such as a frequency comparison signal and a phase comparison frequency signal generated by a PLL circuit wraps around a voltage-controlled oscillator through a wide intermediate ground pattern 46 electrically connected to the spurious frequency signal component. May be output.

  The present invention has been made in view of such a technical background, and an object of the present invention is to connect a filter for removing spurious frequency signal components between a ground pattern region of a PLL circuit and a wide-area ground pattern to control voltage. An object of the present invention is to provide a synthesizer module that eliminates spurious frequency signal components from sneaking into an oscillator.

  In order to achieve the above object, a synthesizer module according to the present invention uses an insulating substrate, and a voltage controlled oscillator and a PLL circuit are mounted on the upper surface of the insulating substrate, and a ground pattern region for the voltage controlled oscillator and a ground pattern region for the PLL circuit. A wide-area ground pattern is formed on the lower surface of the insulating substrate, and a filter for removing the reference signal of the PLL circuit is further mounted on the upper surface of the insulating substrate and a ground pattern area for the filter is formed. First input means having an input end connected to the PLL circuit ground pattern region, a filter output end conductively connected to the filter ground pattern region, and a filter ground pattern region conductively connected to the wide area ground pattern is provided.

  In this case, a conductive connection is made between the ground pattern area for the voltage controlled oscillator and the wide area ground pattern and the ground pattern area for the filter and the wide area ground pattern in the first component via through holes provided in the insulating substrate. It is what you are doing.

  In order to achieve the above object, a synthesizer module according to the present invention uses a laminated insulating substrate composed of an upper insulating substrate and a lower insulating substrate, and a voltage controlled oscillator and a PLL circuit are mounted on the upper surface of the upper insulating substrate. In addition, a ground pattern region for a voltage controlled oscillator and a ground pattern region for a PLL circuit are formed, and a wide-area ground pattern is formed on the lower surface of the lower insulating substrate, and a reference signal for the PLL circuit is further provided on the upper surface of the upper insulating substrate. A filter to be removed is mounted, and an input-side connection pattern region and an output-side connection pattern region that are separately conductively connected to the input end and output end of the filter are formed, and a portion is formed at the junction between the upper insulating substrate and the lower insulating substrate. A ground pattern is formed, and the ground pattern area for the PLL circuit and the input side connection pattern area are guided to the partial ground pattern. Connect comprises a second configuration means conductively connecting the output connection pattern region to a wide area ground pattern.

  In this case, between the ground pattern area for the voltage controlled oscillator and the wide area ground pattern and between the ground pattern area for the filter and the wide area ground pattern in the second constituent means, and between the ground pattern area for the PLL circuit and the partial ground pattern. In addition, the input side connection pattern region and the partial ground pattern are electrically connected through through holes provided in the interposed insulating substrate.

  As described above, according to the synthesizer module according to claim 1, the filter for removing the reference signal of the PLL circuit is mounted on the upper surface of the insulating substrate on which the voltage controlled oscillator and the PLL circuit are mounted, and the insulating substrate A filter for removing the reference signal of the PLL circuit is connected between the PLL circuit ground pattern region and the filter ground pattern region respectively formed on the upper surface of the voltage control oscillator. The PLL circuit ground pattern region is connected via a filter that removes the reference signal of the PLL circuit of this circuit, so that the reference signal of the PLL circuit that passes from the PLL circuit to the voltage controlled oscillator through the grounding means is the reference of this PLL circuit. Blocked by a filter that removes the signal, the reference signal of the PLL circuit wraps around the voltage controlled oscillator There is an effect that it is possible to prevent the input.

  According to the synthesizer module of claim 3, the voltage-controlled oscillator ground pattern region is connected to a wide-area ground pattern formed on the lower surface of the lower insulating substrate, and the PLL circuit ground pattern region is connected to the upper insulating substrate. After connecting to the partial ground pattern formed at the junction of the lower insulating substrate and the lower insulating substrate, it is connected to the wide area ground pattern through a filter that removes the reference signal of the PLL circuit. Combined with the connection of the filter for removing the signal, there is an effect that it is possible to almost completely prevent the reference signal of the PLL circuit that goes from the PLL circuit to the voltage controlled oscillator through the grounding means and is inputted to the voltage controlled oscillator. is there.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an outline of the configuration of a synthesizer module according to the present invention.

  As shown in FIG. 1, the synthesizer module includes a voltage controlled oscillator (VCO) 1, a PLL circuit (PLL) 2, a reference frequency signal generator (X-TAL) 3, and a reference signal removal filter (FL). ) 4. The voltage controlled oscillator 1 has an output terminal 1 (1), a frequency control terminal 1 (2), and a ground terminal 1 (3), and the frequency control terminal 1 (2) is a frequency control output terminal of the PLL circuit 2. 2 (1), the ground terminal 1 (3) is grounded, and a high frequency oscillation signal (RF) is output from the output terminal 1 (1). The PLL circuit 2 has a frequency control output terminal 2 (1), a reference frequency signal input terminal 2 (2), and a ground terminal 2 (3). The reference frequency signal input terminal 2 (2) is a reference frequency generator 3. Is connected to the reference frequency signal output terminal 3 (1), and the ground terminal 2 (3) is connected to the input terminal 4 (1) of the reference signal removal filter 4. The reference frequency generator 3 has a reference frequency signal output terminal 3 (1) and a ground terminal 3 (2), and the ground terminal 3 (2) is grounded. The reference signal removal filter 4 has an input end 4 (1) and an output end 4 (2), and the output end 4 (2) is grounded.

  FIG. 2 is a cross-sectional view showing a transverse cross section of the mounting structure according to the first embodiment of the synthesizer module shown in FIG.

  As shown in FIG. 2, the synthesizer module mounting structure according to this embodiment includes an insulating substrate 5, a voltage controlled oscillator 1, a PLL circuit 2, and a reference frequency signal generator 3 mounted on the upper surface of the insulating substrate 5. , A reference signal removing filter 4, a voltage-controlled oscillator ground pattern region 6, a PLL circuit ground pattern region 7, a reference frequency signal generator ground pattern region 8, and a filter input side formed on the upper surface of the insulating substrate 5, respectively. A connection pattern region 9, a filter output side connection pattern region 10 constituting the filter ground pattern region, and a wide area ground pattern 11 formed on the lower surface of the insulating substrate 5 are provided. Further, a through hole 12 penetrating the insulating substrate 5 is formed between the voltage-controlled oscillator ground pattern region 6 and the wide-area ground pattern 11 so that the voltage-controlled oscillator ground pattern region 6 and the wide-area ground pattern 11 are electrically connected. In addition, a through hole 13 penetrating the insulating substrate 5 is also formed between the filter output side connection pattern region 10 and the wide area ground pattern 11 so that the filter output side connection pattern area 10 and the wide area ground pattern 11 are electrically conductive. It is connected. In this case, the PLL circuit ground pattern region 7, the reference frequency signal generator ground pattern region 8, and the filter input side connection pattern region 9 are integrated with each other.

  As shown in FIG. 1, the voltage controlled oscillator 1 and the PLL circuit 2 are configured such that the frequency control terminal 1 (2) of the voltage controlled oscillator 1 is connected to the frequency control output terminal 2 (1) of the PLL circuit 2, In the PLL circuit 2 and the reference frequency generator 3, the reference frequency signal input terminal 2 (2) of the PLL circuit 2 is connected to the reference frequency signal output terminal 3 (1) of the reference frequency generator 3.

  The synthesizer module having the above-described configuration basically performs the same operation as that of the synthesizer module shown in FIG. 4 described above. The PLL circuit 2 generates a high-frequency oscillation signal output from the voltage-controlled oscillator 1. The frequency is compared with the frequency of the reference frequency signal supplied from the reference frequency generator 3, and the frequency control voltage corresponding to the frequency comparison result is transferred from the control output terminal 2 (1) to the control terminal 1 ( 2), the voltage controlled oscillator 1 is controlled by the supplied frequency control voltage so that its oscillation frequency becomes a predetermined frequency.

  During this operation, the PLL circuit 2 receives a reference signal supplied from the reference frequency generator 3 to the PLL circuit 2, a frequency-divided signal of the high-frequency oscillation signal output from the voltage controlled oscillator 1, etc. If the reference signal removal filter 4 is not connected as in the present invention, the leaked reference signal and the divided signal are leaked from the PLL circuit ground pattern region 7. It is transmitted to the wide-area ground pattern 11 and then transmitted to the ground pattern area 6 for the voltage controlled oscillator, wraps around the voltage controlled oscillator 1 through the grounding means, and is superposed on the clock signal output from the voltage controlled oscillator 1. .

  On the other hand, in this embodiment, a filter for removing the reference signal of the PLL circuit 2, that is, a reference signal removing filter 4 is inserted and connected between the PLL circuit ground pattern region 7 and the wide area ground pattern 11. Therefore, even if the reference signal leaked from the PLL circuit 2 is generated in the PLL circuit ground pattern region 7, the reference signal is greatly attenuated in the reference signal removal filter 4, and is almost entirely in the wide-area ground pattern 11. Since it is not transmitted, the reference signal does not wrap around the voltage controlled oscillator 1 via the grounding means, and the spurious frequency component is not superimposed on the clock signal output from the voltage controlled oscillator 1 and output. .

  Next, FIG. 3 relates to the second embodiment of the synthesizer module shown in FIG. 1, and is a sectional view showing a transverse section of the mounting structure.

  As shown in FIG. 3, the mounting structure of the synthesizer module according to this embodiment includes a stacked upper insulating substrate 5 (1) and lower insulating substrate 5 (2), and an upper surface of the upper insulating substrate 5 (1). Voltage control oscillator 1, PLL circuit 2, reference frequency signal generator 3, reference signal removal filter 4, and voltage control oscillator ground pattern region formed on the upper surface of upper insulating substrate 5 (1), respectively. 6, PLL circuit ground pattern region 7, reference frequency signal generator ground pattern region 8, filter input side connection pattern region 9, filter output side connection pattern region 10, and lower surface of lower insulating substrate 5 (2) A wide-area ground pattern 11 is formed, and an intermediate ground pattern 14 is formed on the joint surface between the upper insulating substrate 5 (1) and the lower insulating substrate 5 (2).

  Further, a through hole 12 penetrating the upper insulating substrate 5 (1) and the lower insulating substrate 5 (2) is formed between the voltage-controlled oscillator ground pattern region 6 and the wide-area ground pattern 11, so that the voltage-controlled oscillator The ground pattern region 6 and the wide area ground pattern 11 are conductively connected, and the upper insulating substrate 5 (1) and the lower insulating substrate 5 (2) are passed between the filter output side connection pattern region 10 and the wide area ground pattern 11. Through-hole 13 is formed, and the output-side connection pattern region 10 and the wide area ground pattern 11 are conductively connected. Further, the upper insulating substrate 5 (1) is connected between the PLL circuit ground pattern region 7 and the intermediate ground pattern 14. ) Is formed so that the PLL circuit ground pattern region 7 and the intermediate ground pattern 14 are conductively connected, and the reference frequency signal generator contact is connected. A through hole 16 penetrating the upper insulating substrate 5 (1) is formed between the pattern region 8 and the intermediate ground pattern 14, and the reference frequency signal generator ground pattern region 8 and the intermediate ground pattern 14 are conductively connected. A through hole 17 penetrating the upper insulating substrate 5 (1) is formed between the filter input side connection pattern region 9 and the filter input side connection pattern region 9 is conductively connected.

  The synthesizer module according to the second embodiment having the above-described configuration basically performs the same operation as that of the synthesizer module according to the first embodiment illustrated in FIG. The PLL circuit 2 compares the frequency of the high-frequency oscillation signal output from the voltage-controlled oscillator 1 with the frequency of the reference frequency signal supplied from the reference frequency generator 3, and a frequency control voltage corresponding to the frequency comparison result is obtained. The voltage is supplied from the control output terminal 2 (1) to the control terminal 1 (2) of the voltage controlled oscillator 1, and the voltage controlled oscillator 1 is controlled by the supplied frequency control voltage so that the oscillation frequency becomes a predetermined frequency.

  Also in the second embodiment, an intermediate ground pattern 14 and an intermediate ground pattern which are conductively connected between the PLL circuit ground pattern region 7 and the wide area ground pattern 11, specifically, the PLL circuit ground pattern region 7. 14 is a filter that removes the reference signal of the PLL circuit 2 between the filter input side connection pattern region 9 conductively connected to 14 and the filter output side connection pattern region 10 conductively connected to the wide area ground pattern 11, that is, a reference Since the signal removal filter 4 is inserted and connected, even if a reference signal leaked from the PLL circuit 2 is generated in the PLL circuit ground pattern region 7, the reference signal is greatly attenuated in the reference signal removal filter 4. Since it is hardly transmitted to the wide area ground pattern 11, the reference signal is transmitted to the voltage controlled oscillator 1 via the grounding means. Writing it eliminates, never spurious frequency components in the clock signal output from the voltage controlled oscillator 1 is output by superimposing.

  In this case, the intermediate ground pattern 14 is used as a ground connection means for connecting the PLL circuit ground pattern region 7 to the filter input side connection pattern region 9. The intermediate ground pattern 14 is formed at the upper insulating substrate 5 ( 1) and the lower insulating substrate 5 (2), that is, the lower surface of the upper insulating substrate 5 (1), the position where the PLL circuit 2 is disposed and the position where the PLL circuit ground pattern region 7 is formed Is the upper surface of the upper insulating substrate 5 (1), and its formation position is different by the thickness of the upper insulating substrate 5 (1), so that the reference signal leaked from the PLL circuit 2 is directly connected to the intermediate ground pattern. 14, coupled with the connection of the reference signal removal filter 4, it is possible to almost completely eliminate the reference signal from wrapping around the voltage controlled oscillator 1. Little spurious frequency component is output by superimposing a clock signal output from the 1.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the outline | summary of a structure of the synthesizer module by this invention, and shows the principal part structure. FIG. 2 is a cross-sectional view showing a transverse cross section of the mounting structure according to the first embodiment of the synthesizer module shown in FIG. 1. FIG. 10 is a cross-sectional view showing a transverse cross section of the mounting structure according to the second embodiment of the synthesizer module shown in FIG. 1. It is a block diagram which shows an example of the circuit structure of a known synthesizer module. It is sectional drawing which shows the cross section of the mounting structure of Unexamined-Japanese-Patent No. 2004-119598.

Explanation of symbols

1 Voltage controlled oscillator (VCO)
2 PLL circuit (PLL)
3 Reference frequency signal generator (X-TAL)
4 Reference signal removal filter (FL)
5 Insulating substrate 5 (1) Upper insulating substrate 5 (2) Lower insulating substrate 6 Voltage-controlled oscillator ground pattern area 7 PLL circuit ground pattern area 8 Reference frequency signal generator ground pattern area 9 Filter input side connection pattern area 10 Filter output side connection pattern area (filter ground pattern area)
11 Wide-area ground pattern 12, 13, 15, 16, 17 Through hole 14 Intermediate ground pattern

Claims (4)

Using an insulating substrate, a voltage controlled oscillator and a PLL circuit are mounted on the upper surface of the insulating substrate, a ground pattern region for the voltage controlled oscillator and a ground pattern region for the PLL circuit are formed, and a wide area ground pattern is formed on the lower surface of the insulating substrate. In the synthesizer module formed, a filter for removing the reference signal of the PLL circuit is further mounted on the upper surface of the insulating substrate, the ground pattern area for the filter is formed, and the input end of the filter is connected to the ground for the PLL circuit. A synthesizer module, wherein the synthesizer module is connected to a pattern region, the output end of the filter is conductively connected to the filter ground pattern region, and the filter ground pattern region is conductively connected to the wide area ground pattern. The voltage-controlled oscillator ground pattern region and the wide-area ground pattern and the filter ground pattern region and the wide-area ground pattern are conductively connected through through holes provided in the insulating substrate, respectively. The synthesizer module according to claim 1. Using a laminated insulating substrate composed of an upper insulating substrate and a lower insulating substrate, a voltage controlled oscillator and a PLL circuit are mounted on the upper surface of the upper insulating substrate, and a ground pattern region for the voltage controlled oscillator and a ground pattern region for the PLL circuit are provided. And a synthesizer module having a wide-area ground pattern formed on a lower surface of the lower insulating substrate, wherein a filter for removing a reference signal of the PLL circuit is further mounted on the upper surface of the upper insulating substrate, and an input end of the filter And an input-side connection pattern region and an output-side connection pattern region that are separately conductively connected to the output end, and a partial ground pattern is formed at a joint between the upper insulating substrate and the lower insulating substrate, and the PLL The circuit ground pattern region and the input side connection pattern region are conductively connected to the partial ground pattern, and the output Synthesizer module, wherein a side connecting pattern region is conductively connected to the wide area ground pattern. Between the ground pattern area for the voltage controlled oscillator and the wide area ground pattern, between the ground pattern area for the filter and the wide area ground pattern, between the ground pattern area for the PLL circuit and the partial ground pattern, and 4. The synthesizer module according to claim 3, wherein the input side connection pattern region and the partial ground pattern are conductively connected through through holes provided in an insulating substrate interposed therebetween. 5.

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