JP6395638B2 - Wireless device - Google Patents

Description

  The present invention relates to a wireless device.

  For example, in a multilayer substrate used in a wireless device or the like, when a DC signal, a baseband signal, or the like is transmitted to the inner layer of the multilayer substrate, it may be transmitted through a through hole. In this case, in order to reduce the cost, the through hole is often constituted by a through type that penetrates the multilayer substrate.

  FIG. 16 shows a conventional through-type through hole. In this example, in the multilayer substrate 100, the first layer 111 to the sixth layer 116 made of six layers of copper foil are formed on the substrate 101 made of a dielectric, and the first layer 111, the third layer 113, the first layer The through hole 120 connects the four layers and the sixth layer 116. In such a configuration, when the spurious signal indicated by the hatched arrow is supplied to the first layer 111 together with the transmission signal indicated by the white arrow, the spurious signal is transmitted through the through hole 120 to the sixth layer. 116 and is radiated from the sixth layer 116 as a radio wave. In a wireless device or the like, since the allowable value of spurious radiation is specified, it is necessary to suppress spurious so as not to exceed the allowable value.

  As techniques for suppressing such spurious, there are techniques shown in Patent Documents 1 to 3. In the technique disclosed in Patent Document 1, the propagation of spurious signals is suppressed by dividing the ground into first and second grounds in the inner layer.

  In the technique disclosed in Patent Document 2, when a signal line is arranged so as to divide the ground layer, a jumper resistor or the like is used to prevent the ground from becoming unstable and increasing the level of the spurious signal. Is used to connect the ground.

  Further, in the technique disclosed in Patent Document 3, the spurious signal is suppressed by changing the length of the conductor via to change the frequency of the resonance point.

JP 2006-073673 A JP 2010-192681 A JP 2007-158675 A

  By the way, the technique disclosed in Patent Document 1 has a problem that when the frequency of the spurious signal is increased, the spurious signal propagates inside the dielectric and radio waves are radiated from the back surface of the substrate.

  Further, in the technique disclosed in Patent Document 2, since the slit width needs to be λ / 8 or more, there is a limit to the effective frequency band. Further, when the propagating frequency increases, there is a problem that a spurious signal propagates inside the dielectric substrate and is emitted from the back surface of the substrate.

  Further, the technique disclosed in Patent Document 3 has a problem that the length of the conductor via needs to be extremely shortened in order to suppress a high-frequency spurious signal, which makes it difficult to manufacture. Moreover, since it is necessary to arrange a shield via, there is a problem that a necessary area increases. Furthermore, there is a problem that it is necessary to use a non-through-type through hole in order to adjust the length of the conductor via.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a radio apparatus that can reliably suppress high-frequency spurious signals with a simple configuration.

In order to solve the above problems, the present invention provides a wireless device having a multilayer board on which electronic components are arranged, wherein the multilayer board includes a first surface on which the electronic components are arranged, and a back side surface of the first surface. A through-type through hole inserted between the first surface and the second surface of the multilayer substrate, and disposed on the first surface. And a transmission line connected to the through-type through hole for transmitting a predetermined signal, a cut portion in which a part of the transmission line is cut in the vicinity of the through-type through hole, and a conductive member. A reflective element that is at least partially covered, the conductive member is a structure that electrically connects the cut portions of the transmission line, and reflects a spurious signal superimposed on the transmission line; and the multilayer substrate As well as A casing having a structure that absorbs or shields a signal reflected by the reflective element by disposing a conductive member on the first surface side of the layer substrate and does not shield the second surface side on which the antenna is disposed. It is characterized by having.
According to such a configuration, it is possible to reliably suppress high-frequency spurious signals with a simple configuration.

Further, the present invention is characterized in that the reflection characteristic of the reflection element is adjusted by adjusting the cut width of the cut portion.
According to such a configuration, the target spurious signal can be suppressed with high accuracy by a simple configuration.

Further, the present invention is characterized in that a plurality of the through-type through holes are arranged close to each other, and a ground wiring is arranged between the plurality of through-type through holes on the second surface side.
According to such a configuration, radiation from the second surface can be suppressed when there are a plurality of through-type through holes.

In addition, the present invention is characterized in that the through-type through holes arranged in proximity are set to have a smaller diameter than other through-type through holes.
According to such a configuration, it is possible to further suppress radiation from the second surface when a plurality of through holes exist by facilitating the arrangement of the ground wiring.

  According to the present invention, it is possible to provide a wireless device that can reliably suppress high-frequency spurious signals with a simple configuration.

It is a figure which shows the basic composition of the multilayer substrate which the radio | wireless apparatus which concerns on embodiment of this invention has. It is a figure which shows embodiment of this invention. It is a figure which shows a passage loss characteristic when a 0-ohm chip resistance element is used for embodiment shown in FIG. It is a figure which shows a passage loss characteristic when a 10-ohm chip resistance element is used for embodiment shown in FIG. It is a figure which shows the equivalent circuit of the chip resistance element shown in FIG. It is a figure which shows the passage loss characteristic at the time of adjusting the gap shown in FIG. It is a figure which shows the structural example used as the comparison object with embodiment shown in FIG. It is a figure which shows the structural example used as the comparison object with embodiment shown in FIG. It is a figure which shows the electric field strength of the spurious signal radiated | emitted to the back surface of a multilayer substrate at the time of supplying a spurious signal to embodiment shown in FIG. It is a figure which shows the electric field strength of the spurious signal radiated | emitted to the back surface of a multilayer substrate at the time of removing a chip resistance element shown in FIG. It is a figure which shows the electric field strength of the spurious signal radiated | emitted to the back surface of a multilayer substrate at the time of supplying a spurious signal with respect to the structure shown in FIG. FIG. 9 is a diagram showing the electric field strength of a spurious signal radiated to the back surface of the multilayer substrate when a spurious signal is supplied to the configuration shown in FIG. 8. It is a figure which shows the structural example in case a some through hole exists. It is a figure which shows distribution of the electric field strength at the time of seeing FIG. 13 (A) from a X direction. It is a figure which shows distribution of the electric field strength at the time of seeing FIG. 13 (B) from the X direction. It is sectional drawing which shows the structure of a multilayer substrate.

  Next, an embodiment of the present invention will be described.

(A) Description of Basic Configuration of Embodiment of the Present Invention FIG. 1 is a diagram illustrating a configuration example of a multilayer substrate included in a wireless device according to an embodiment of the present invention. The multilayer substrate 100 shown in FIG. 1 corresponds to the multilayer substrate 100 shown in FIG. As shown in FIG. 1, in the multilayer substrate 100 according to the embodiment of the present invention, a first layer 111 made of, for example, copper foil is disposed on the first surface 101a of the substrate 101 made of dielectric. In addition, a sixth layer 116, which is also formed of copper foil or the like, is disposed on the second surface 101b which is the back surface of the first surface. Between the first layer 111 and the sixth layer 116, the second layer 112 to the fifth layer 115, which are intermediate layers, are arranged. The first layer 111, the third layer 113, the fourth layer, and the sixth layer 116 are connected by a through hole 120. The multilayer substrate 100 is housed in a housing (not shown). The housing has a configuration in which the first surface 101a side of the multilayer substrate 100 is shielded by a conductive member and the second surface 101b side is not shielded. In the wireless device, for example, an antenna for transmission / reception is arranged on the second surface 101b side, and transmits / receives radio waves via an unshielded portion of the housing.

  Predetermined signals (for example, a DC signal and a baseband signal) input from the port P1 provided in the first layer 111 are transferred to the third layer via the transmission line 111a, the reflective element 130, and the transmission line 111b. 113 and transmitted to the port P2 via the transmission line 113a.

  A reflection element 130 that reflects the frequency band of the spurious signal is formed between the transmission line 111a and the transmission line 111b of the first layer 111. The signal reflected by the reflective element 130 is reflected or shielded by the conductive member of the housing. In FIG. 1, the reflective element 130 is shown as an element having a rectangular shape, but the detailed configuration will be described later.

  In the present embodiment, in the vicinity of the through hole 120, the transmission line is cut into the transmission line 111a and the transmission line 111b, and the reflective element 130 that electrically connects the transmission line 111a and the transmission line 111b is formed on the cut portion. The electric field radiated from the multilayer substrate 100 can be suppressed by suppressing the spurious signal (high frequency signal) immediately before being provided and supplied to the through hole 120. The reflective element 130 has a structure in which at least a part of the dielectric is covered with a conductive member, and is configured to electrically connect the transmission line 111a and the transmission line 111b with the conductive member.

(B) Description of Embodiment of the Present Invention FIG. 2 is a diagram showing a configuration example of an embodiment of the present invention. In FIG. 2, parts corresponding to those in FIG. In FIG. 2, the reflective element 130 is replaced with a chip resistive element 131 as compared with FIG. 1. Other configurations are the same as those in FIG. The chip resistance element 131 is configured by covering the outer periphery of the dielectric with a conductive member, and is configured by a resistance element having 0Ω or a low resistance value as described later. Since the transmission line 111a and the transmission line 111b are spaced apart from each other, a gap 111c is formed between them. The chip resistance element 131 is disposed on the gap 111c and is electrically connected to the end portions of the transmission lines 111a and 111b by, for example, soldering. Thus, the transmission line 111a and the transmission line 111b cut by the gap 111c are electrically connected by the conductive member of the chip resistance element 131. The spurious signal transmitted through the transmission line 111 a is reflected and not transmitted to the through hole 120 because impedance mismatch occurs in the chip resistor 131.

  FIG. 3 is a diagram showing a passage loss characteristic when a chip resistance element 131 having a resistance value of 0Ω is used. As shown in FIG. 3, when a chip resistance element 131 having a resistance value of 0Ω is used, it has a so-called band-stop filter characteristic in which a passage loss increases in a band of about 40 to 50 GHz. For this reason, a spurious signal can be suppressed by using a desired chip resistance element according to the frequency of the spurious signal.

  FIG. 4 shows the passage loss characteristic of the chip resistance element 131 having a resistance value of 10Ω. As shown in FIG. 4, even when a chip resistance element 131 having a resistance value of 10Ω is used, it has a so-called band stop filter characteristic. Further, the passage loss is smaller than that of the chip resistance element 131 having a resistance value of 0Ω shown in FIG. Therefore, the chip resistance element 131 having a resistance value can also be used as a reflection element. However, when the resistance value is large, signals other than the spurious signal transmitted through the chip resistance element 131 are also attenuated. Therefore, in the case of a chip resistor having a resistance value, high impedance transmission in which almost no current flows. It is desirable to use for wires.

  FIG. 5 shows a cross-sectional view and an equivalent circuit of the chip resistance element 131 shown in FIG. As shown in FIG. 5A, the equivalent circuit of the chip resistor element 131 can be represented as a circuit in which a capacitance component C1 is connected in parallel to a circuit in which a resistance component R and an inductance component L are connected in series. The gap 111c provided between the transmission line 111a and the transmission line 111b can be expressed as a capacitance component C2 connected in parallel to the equivalent circuit of the chip resistance element 131.

  FIG. 6 shows a passage loss characteristic when the width of the gap 111c provided between the transmission line 111a and the transmission line 111b shown in FIG. 5 is adjusted between 0.1 mm and 0.4 mm. More specifically, the solid line shows the passage loss characteristic when the gap 111c is set to 0.10 mm, the broken line with a short interval shows the passage loss characteristic when the gap 111c is set to 0.25 mm, and the broken line with a long interval Indicates a passage loss characteristic when the gap 111c is set to 0.40 mm. In this manner, the frequency to be attenuated can be adjusted by adjusting the gap interval. In the example of FIG. 6, the frequency to be attenuated can be adjusted by about 3 GHz by adjusting between 0.1 mm and 0.4 mm.

  Thus, by adjusting the gap 111c provided between the transmission line 111a and the transmission line 111b, the frequency to be reflected can be adjusted. For example, as shown in FIG. 3 and FIG. Even when the characteristics of the chip resistance element 131 differ depending on the type or individual, a desired characteristic can be obtained by adjusting the gap 111c.

  7 and 8 are diagrams showing a comparative configuration example for verifying the effect of the embodiment shown in FIG. Compared with FIG. 2, the configuration of FIG. 7 excludes the chip resistance element 131 and connects the through hole 120 to the ground 140 in the third layer 113. Other configurations are the same as those in FIG. 8, the chip resistor 131 is excluded and the through hole 120 is terminated at the fourth layer 114 and shielded by the copper foil of the fifth layer 115, as compared with FIG. Other configurations are the same as those in FIG.

  FIG. 9 shows the electric field strength of the spurious signal radiated to the second surface 101b side of the multilayer substrate 100 when a spurious signal (here, a signal of 48 GHz) is supplied to the port P1 of the embodiment shown in FIG. FIG. FIG. 9 is a view of FIG. 2 as viewed from the direction of the arrow X. Black indicates a place where the electric field strength is high, and white indicates a place where the electric field strength is low. FIG. 10 shows the state of the multilayer substrate 100 when the spurious signal (48 GHz signal similar to the above-described case) is supplied to the port P1 with the chip resistor 131 excluded from the embodiment shown in FIG. It is a figure which shows the electric field strength of the spurious signal radiated | emitted to the 2nd surface 101b side. 11 and 12 show the second surface 101b of the multilayer substrate 100 when a spurious signal (the same 48 GHz signal as described above) is supplied to the port P1 of the configuration example shown in FIGS. It is a figure which shows the electric field strength of the spurious signal radiated | emitted to the side.

  From the comparison of FIGS. 9 to 12, in the configuration excluding the chip resistor 131 and the gap 111c, a strong electric field is radiated to the second surface 101b side of the multilayer substrate 100 as shown in FIG. On the other hand, in the embodiment shown in FIG. 2, a strong electric field is not radiated to the second surface 101b side of the multilayer substrate 100 as shown in FIG. That is, in the embodiment of the present invention, since the spurious signal is reflected by the chip resistor element 131 before flowing into the through hole 120, a strong electric field is not radiated to the second surface 101 b side of the multilayer substrate 100.

  On the other hand, in the configuration shown in FIG. 7 connected to the ground 140 in the third layer 113, a strong electric field is radiated to the second surface 101b side of the multilayer substrate 100 as shown in FIG. It can be seen that the effect of connecting to the ground 140 at 113 is low. Further, in the configuration in which the through hole 120 is terminated in the fourth layer 114, the electric field generated on the second surface 101b side of the multilayer substrate 100 is weaker as shown in FIG. Compared with the embodiment of the present invention shown, the electric field generated inside the multilayer substrate 100 is stronger.

  That is, in the embodiment of the present invention, since the spurious signal is reflected by the chip resistor element 131 before flowing into the through hole 120, the electric field due to the spurious signal is on the second surface 101b side of the multilayer substrate 100 through the through hole 120. Can be prevented from being emitted.

  As described above, according to the embodiment of the present invention, the chip resistor element 131 is disposed on the gap 111c of the transmission lines 111a and 111b to attenuate the spurious signal flowing into the through hole 120 in advance. Can do. Thereby, it is possible to prevent the spurious signal from being radiated from the second surface 101b side of the multilayer substrate 100. In the embodiment of the present invention, it is possible to adjust the frequency to be suppressed by adjusting the width of the gap 111c of the transmission lines 111a and 111b. it can. Further, according to the embodiment of the present invention, the circuit board can be formed in a smaller size as compared with the case where a stub or the like is formed.

(C) Description of Modified Embodiment It goes without saying that the above embodiment is merely an example, and the present invention is not limited to the case described above. For example, in the above embodiment, the case where there is only one through hole 120 has been described as an example, but the present invention can also be applied to a case where there are a plurality of through holes. That is, when there are a plurality of through holes, spurious signals can be suppressed by providing the reflective element 130 in the vicinity of the through hole of the transmission line connected to each through hole on the first surface 101a. .

  In addition, when there are a plurality of through holes, by arranging a ground wiring between the through holes, the electric field strength of the spurious signal radiated from the second surface 101b side of the multilayer substrate 100 can be reduced. . FIG. 13A shows a configuration example in which the diameters of the through holes 121 and 122 are reduced and the ground wiring 116 b is disposed between the through holes 121 and 122 of the sixth layer 116. Note that FIG. 13B shows a configuration example when such a countermeasure is not taken. Comparing FIG. 13A and FIG. 13B, in FIG. 13B, nothing is arranged between the two through holes 121 and 122 arranged in the opening 116a formed in the sixth layer 116. Although not shown, in FIG. 13A, a ground wiring 116b is disposed between the two through holes 121 and 122. Further, the diameters of the through holes 121 and 122 which are 0.3φ in FIG. 13B are changed to 0.2φ in FIG. 13A.

  14 and 15 are diagrams showing electric field intensity distributions when FIGS. 13A and 13B are viewed from the X direction. From the comparison between FIG. 14 and FIG. 15, it can be seen that the electric field strength in FIG. 14 corresponding to FIG. 13A is lower than that in FIG. 15 corresponding to FIG. From the above, when there are a plurality of through holes, it is possible to reduce the electric field strength of the spurious by arranging the ground wiring between the through holes. Note that by reducing the diameter of the through holes, the distance between the through holes can be secured and the ground wiring can be easily arranged.

  In the above embodiment, the case where the chip resistor 131 is used as the reflective element 130 has been described as an example. However, a normal resistor (for example, a metal film resistor) is used instead of the chip resistor. You can also. Furthermore, instead of the resistance element, a structure in which at least a part of the dielectric is covered with a conductive member is used, and the transmission line 111a and the transmission line 111b are electrically connected by the conductive member of the structure. Also good. For example, a chip inductor can be used.

  In the above embodiment, the multilayer substrate used for the wireless device has been described as an example. However, it is needless to say that the present invention can be applied to other devices using high-frequency signals.

DESCRIPTION OF SYMBOLS 100 Multilayer substrate 101 Dielectric 101a 1st surface 101b 2nd surface 111 1st layer 111a, 111b Transmission line 111c Gap (cutting part)
112 2nd layer 113 3rd layer 114 4th layer 115 5th layer 116 6th layer 120 Through hole 130 Reflective element 131 Chip resistance element (structure)

Claims (4)

In a wireless device having a multilayer substrate on which electronic components are arranged,
The multilayer substrate has a first surface on which the electronic component is disposed, and a second surface on the back side surface of the first surface on which the antenna is disposed,
A through-type through hole inserted between the first surface and the second surface of the multilayer substrate;
A transmission line disposed on the first surface and connected to the through-type through hole for transmitting a predetermined signal;
In the vicinity of the through-type through hole, at least a part of the dielectric is covered with a cut portion in which a part of the transmission line is cut and a conductive member, and the conductive member electrically connects the cut portion of the transmission line. A reflective element that reflects a spurious signal superimposed on the transmission line,
The second surface on which the antenna is disposed by accommodating the multilayer substrate and absorbing or shielding a signal reflected by the reflective element by disposing a conductive member on the first surface side of the multilayer substrate. A housing having a structure that does not shield the side,
A wireless device comprising:   The radio apparatus according to claim 1, wherein the reflection characteristic of the reflection element is adjusted by adjusting a cut width of the cut portion.   The plurality of through-type through holes are arranged close to each other, and a ground wiring is arranged between the plurality of through-type through holes on the second surface side. Wireless device.   4. The radio apparatus according to claim 3, wherein the through-type through holes arranged close to each other are set to have a smaller diameter than other through-type through holes.

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