Wireless communication device

Abstract

To provide a technique capable of reducing noise reaching an antenna with a simple configuration.SOLUTION: A wireless communication device includes a circuit board having a board surface on which a first circuit component serving as a noise source and a second circuit component disposed around the first circuit component are provided, an antenna provided at an edge of the circuit board or around the circuit board, and at least one parasitic protruding conductor provided on the board surface and grounded, the protruding conductor being provided at a position closer to the first circuit component than to the second circuit component. A distance between the protruding conductor and the first circuit component is shorter than a distance between the protruding conductor and the antenna.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to wireless communication devices. [Background technology]

[0002] In recent years, with the miniaturization of communication devices, a communication antenna is sometimes provided on a substrate on which a chip having a communication function is mounted (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2011-142542 Summary of the Invention [Problem to be solved by the invention]

[0004] A crystal oscillator that outputs a reference signal, etc., is usually mounted on the circuit board of a communication device. A crystal oscillator is a circuit component that generates noise. Noise from crystal oscillators can affect the transmission and reception of antennas, so measures are taken to reduce the noise that reaches the antenna, such as mounting noise-reducing chip components on the circuit board or covering the peripheral circuits containing the noise source with a shield cover.

[0005] However, these measures increase the cost of the product, so a simpler method of reducing the noise reaching the antenna is desired. [Means for solving the problem]

[0006] A wireless communication device according to an embodiment includes a circuit board having a board surface on which a first circuit component that is a noise source and a second circuit component disposed around the first circuit component are provided, an antenna provided on an edge of the circuit board or around the circuit board, and at least one grounded, non-powered protruding conductor provided on the board surface. The protruding conductor is located closer to the first circuit component than the second circuit component. The distance between the protruding conductor and the first circuit component is shorter than the distance between the protruding conductor and the antenna. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to reduce noise reaching an antenna with a simple configuration. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view illustrating an example of a wireless communication device according to the first embodiment. [Figure 2] FIG. 2 is a plan view of the circuit board. [Figure 3] FIG. 3 is a cross-sectional view of a main part of the circuit board. [Figure 4] FIG. 4 is a diagram showing a case where the first projecting conductor is disposed at a position deviated from the imaginary line L1. [Figure 5] FIG. 5 is a partial perspective view illustrating an example of a wireless communication device according to the second embodiment. [Figure 6] FIG. 6 is a partial perspective view illustrating an example of a wireless communication device according to the third embodiment. [Figure 7] FIG. 7 is a partial perspective view illustrating an example of a wireless communication device according to the fourth embodiment. [Figure 8] FIG. 8 is a partial perspective view illustrating an example of a wireless communication device according to the fifth embodiment. [Figure 9] FIG. 9 is a partial perspective view showing an example of a wireless communication device according to the sixth embodiment. [Figure 10] FIG. 10 is a partial perspective view illustrating an example of a wireless communication device according to the seventh embodiment. [Figure 11] FIG. 11 is a diagram showing an example of a model used in a verification test. [Figure 12] FIG. 12 is a diagram showing a part of the model of the second embodiment. [Figure 13] FIG. 13 is a diagram showing an example of the arrangement of protruding conductors in the models of Examples 3, 4, and 5. In FIG. [Figure 14] FIG. 14 is a diagram showing a part of the model of Examples 6 and 7. [Figure 15] FIG. 15 is a diagram showing a part of the model of Example 8. [Figure 16] FIG. 16 is a diagram showing a part of the model of Example 9. [Figure 17] FIG. 17 is a diagram showing a model of Example 10. [Figure 18] FIG. 18 is a diagram showing a part of the model of Example 11. [Figure 19] FIG. 19 is a diagram showing the frequency characteristics of S21 when the length of the protruding conductor is changed using Example 1. [Figure 20] FIG. 20 is a diagram showing the frequency characteristics of S21 when the length of the protruding conductor is changed using Example 1. [Figure 21] FIG. 21 is a diagram showing the frequency characteristics of S21 when the distance between the noise source and the protruding conductor is changed using the first embodiment. [Figure 22] FIG. 22 is another diagram showing the frequency characteristics of S21 when the distance between the noise source and the protruding conductor is changed using the first embodiment. [Figure 23] FIG. 23 is a diagram showing an image of the electromagnetic field distribution near a noise source. [Figure 24] FIG. 24 is a diagram showing a radiation pattern of a noise source. [Figure 25] FIG. 25 is a diagram showing a radiation pattern of a noise source. [Figure 26] FIG. 26 is a diagram showing the frequency characteristics of S21 when the position of the protruding conductor is changed using Example 1. [Figure 27] FIG. 27 is a diagram showing the frequency characteristics of S21 when the number of protruding conductors is changed. [Figure 28] FIG. 28 is a diagram showing an image of the electromagnetic field distribution in the vicinity of a noise source. [Figure 29] FIG. 29 is a diagram showing the frequency characteristics of S21 in the sixth embodiment. [Figure 30] FIG. 30 is a diagram showing the frequency characteristics of S21 in the seventh embodiment. [Figure 31] FIG. 31 is a diagram showing the frequency characteristics of S21 in the eighth embodiment. [Figure 32] FIG. 32 is a diagram showing the frequency characteristics of S21 in the ninth embodiment. [Figure 33] FIG. 33 is a diagram showing the frequency characteristics of S21 in the tenth embodiment. [Figure 34] FIG. 34 is a diagram showing the frequency characteristics of S21 in the eleventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] First, the contents of the embodiment will be listed and explained. [Outline of the embodiment]

[0010] (1) A wireless communication device according to an embodiment includes a circuit board having a board surface on which a first circuit component that is a noise source and a second circuit component disposed around the first circuit component are provided, an antenna provided on an edge of the circuit board or around the circuit board, and at least one grounded, non-powered protruding conductor provided on the board surface. The protruding conductor is located closer to the first circuit component than the second circuit component. The distance between the protruding conductor and the first circuit component is shorter than the distance between the protruding conductor and the antenna. According to the above configuration, the protruding conductor provided in a position relatively close to the first circuit component resonates with noise from the first circuit component, and this resonance causes the noise to be absorbed and attenuated by the protruding conductor. As a result, with a simple configuration in which a protruding conductor is provided near the first circuit component, it is possible to reduce noise reaching the antenna from the first circuit component.

[0011] (2) In the wireless communication device of (1) above, the protruding conductor may be disposed in a region between the first circuit component and the antenna. In this case, the protruding conductor is disposed between the first circuit component and the antenna, and therefore can absorb noise radiated from the first circuit component toward the antenna, effectively reducing the noise reaching the antenna.

[0012] (3) In the wireless communication device of (1) above, when the at least one protruding conductor includes two or more protruding conductors, the two or more protruding conductors may be arranged to surround the first circuit component. In this case, noise radiated from the first circuit component toward the surroundings can be absorbed by the two or more protruding conductors, and noise reaching the antenna can be more effectively reduced.

[0013] (4) In the wireless communication device of (1) or (2) above, the protruding conductor may be arranged on a passing line, which is a straight line that passes through the first circuit component and the antenna and minimizes the distance between the first circuit component and the antenna. In this case as well, one or more protruding conductors can be disposed at a position sandwiched between the first circuit component and the antenna, making it possible to more effectively reduce noise reaching the antenna.

[0014] (5) In any one of the wireless communication devices (1) to (4) above, the protruding conductor may have a base end connected to the substrate surface and to a ground conductor, and a tip end that is an electrically open end. In this case, the protruding conductor can be provided on the circuit board by connecting it to the substrate surface, so as long as there is at least space to connect the base end, additional protruding conductors can be mounted even after a large number of chips and circuits have been mounted on the circuit board.

[0015] (6) In the wireless communication device of (5) above, the protruding conductor may include a pin-shaped main body portion extending from the base end portion to the tip end portion. In this case, the space required for providing the protruding conductors on the substrate surface can be minimized. This makes it easier to mount additional protruding conductors on the circuit board after a large number of chips and circuits have been mounted on it.

[0016] (7) In the wireless communication device of (5) above, the protruding conductor may include a main body portion having a spiral shape extending from the base end to the tip end in a direction intersecting the substrate surface. In this case, since the main body of the protruding conductor has a spiral shape, it is possible to keep the protruding height from the circuit board low while ensuring the required length of the protruding conductor.

[0017] (8) In the wireless communication device of (5) above, the protruding conductor may include a plate-shaped main body portion extending from the base end portion to the tip end portion. In this case, the protruding conductor has a larger width in the direction parallel to the board surface than, for example, a pin-shaped protruding conductor, and therefore can absorb noise while shielding it from the first circuit component.

[0018] (9) In the wireless communication device of (6) above, the main body may have a protrusion extending from the base end along a direction intersecting the substrate surface, and a horizontal extension extending from the tip of the protrusion to the tip end along the surface direction of the substrate surface. In this case, the horizontally extending portion can ensure the length required for the protruding conductor while keeping the protruding height from the circuit board low.

[0019] (10) In any one of the wireless communication devices (5) to (9) above, the length from the base end to the tip end of the protruding conductor may be 0.2 times or more and 0.25 times or less the wavelength of the radio waves transmitted and received by the antenna. If the length of the protruding conductor is less than 0.2 times the wavelength of the radio waves transmitted and received by the antenna or more than 0.25 times the wavelength, the resonant frequency of the protruding conductor will be significantly different from the frequency of the radio waves transmitted and received by the antenna, and noise that is close to the frequency of the radio waves transmitted and received by the antenna may not be effectively absorbed by the protruding conductor. By setting the length of the protruding conductor to be 0.2 to 0.25 times the wavelength of the radio waves transmitted and received by the antenna, noise in the vicinity of the frequency of the radio waves transmitted and received by the antenna is effectively absorbed by the protruding conductor.

[0020] (11) In the wireless communication device of (5) above, the protruding conductor may further have a rod-shaped main body portion extending from the base end to the tip end in a direction intersecting the substrate surface, and a plate-shaped conductor portion provided at the end of the main body portion on the tip end side. In this case, an appropriate capacitance can be provided to the tip end of the protruding conductor, and the noise absorption effect can be maintained even if the length of the main body is made shorter, which makes it possible to reduce the size of the protruding conductor.

[0021] (12) In the wireless communication device of (1) above, the protruding conductor may have a first end connected to a first point on the substrate surface, a second end connected to a second point on the substrate surface different from the first point, and a rod-shaped main body connecting the first end and the second end. In this case, the protruding conductor protrudes from the first and second points and has a shape in which the protruding portions from both points are connected, so that one protruding conductor can achieve the same effect as when two protruding conductors are provided protruding from one point on the substrate surface.

[0022] (13) In the wireless communication device of (12) above, the length from the first end to the second end of the protruding conductor may be 0.4 times or more and 0.5 times or less the wavelength of the radio waves transmitted and received by the antenna. If the length from the first end to the second end is less than 0.4 times the wavelength of the radio waves transmitted and received by the antenna or more than 0.5 times the wavelength, the resonant frequency of the protruding conductor will be significantly different from the frequency of the radio waves transmitted and received by the antenna, and noise that is close to the frequency of the radio waves transmitted and received by the antenna may not be effectively absorbed by the protruding conductor. By setting the length of the protruding conductor to be 0.4 to 0.5 times the wavelength of the radio waves transmitted and received by the antenna, noise in the vicinity of the frequency of the radio waves transmitted and received by the antenna is effectively absorbed by the protruding conductor.

[0023] (14) In the wireless communication device of (5) above, the at least one protruding conductor may be plural, and the plural protruding conductors may include a first conductor and a second conductor, and the length from the base end to the tip end of the first conductor may be different from the length from the base end to the tip end of the second conductor. In this case, the resonant frequency of the first conductor is different from the resonant frequency of the second conductor. Therefore, when the antenna transmits and receives two radio waves with different frequencies, by setting the resonant frequency of the first conductor and the resonant frequency of the second conductor to values ​​corresponding to the two radio waves, the noise for each of the two radio waves can be absorbed by the first conductor and the second conductor.

[0024] (15) In the wireless communication device of (14) above, when the antenna is capable of transmitting and receiving a first radio wave having a first wavelength and a second radio wave having a second wavelength different from the first wavelength, the length from the base end to the tip end of the first conductor may be 0.2 to 0.25 times the first wavelength, and the length from the base end to the tip end of the second conductor may be 0.2 to 0.25 times the second wavelength. In this case, noise in the vicinity of the frequency of the first radio wave transmitted and received by the antenna is effectively absorbed by the first conductor, and noise in the vicinity of the frequency of the second radio wave is effectively absorbed by the second conductor.

[0025] (16) A wireless communication device according to another embodiment includes a circuit board having a board surface on which a first circuit component that is a noise source and a second circuit component disposed around the first circuit component are provided, an antenna provided at an edge of the circuit board or around the circuit board, and at least one grounded, unpowered protruding conductor provided on the board surface, wherein the distance between the protruding conductor and the first circuit component is shorter than the distance between the protruding conductor and the antenna.

[0026] (17) In the wireless communication device of (16) above, the first circuit component may include any one of a crystal oscillator, a USB connector, and a LAN chip.

[0027] [Details of the embodiment] Preferred embodiments will now be described with reference to the drawings. At least some of the embodiments described below may be combined in any manner. [Regarding the first embodiment] FIG. 1 is a perspective view illustrating an example of a wireless communication device according to the first embodiment. The wireless communication device 1 includes, for example, a wireless LAN router capable of wireless LAN communication. The wireless communication device 1 includes a wireless module 2 and a housing 6.

[0028] The housing 6 accommodates the wireless module 2 therein. Note that a part of the housing 6 is omitted in Fig. 1. The wireless module 2 is fixed inside the housing 6. The housing 6 has legs 6a for installing the wireless communication device 1. Therefore, the wireless communication device 1 of this embodiment is installed and used indoors or outdoors. The housing 6 may also be installed and used on a wall. In this case, the housing 6 may have installation holes that engage with protruding members that protrude from the wall instead of the legs 6a. The housing 6 may also have a bracket for installing the wireless communication device 1 on an outdoor structure.

[0029] The wireless module 2 has a circuit board 3 and an antenna 4. The circuit board 3 has a board surface 3a. The wireless module 2 further includes mounted components mounted on the circuit board 3. The mounted components are provided on a board surface 3a of the circuit board 3.

[0030] The circuit board 3 is, for example, a rectangular rigid board made of a dielectric material. The components mounted on the circuit board 3 are components necessary to realize the functions of the wireless communication device 1 (wireless module 2). The mounted components include a first circuit component and a second circuit component. The first circuit component is a circuit component that is a noise source. The second circuit component is a circuit component that generates less noise than the first circuit component. The second circuit component is arranged around the first circuit component. The first circuit component can be at least a noise source for the antenna 4. The second circuit component does not become a noise source for the antenna 4.

[0031] The mounted components include a wireless chip 8, a crystal oscillator 10, a processing circuit chip 12, a LAN chip 13, a USB connector 14, and a plurality of LAN connectors 16. The mounted components also include other circuit chips and chip elements such as chip resistors and chip coils.

[0032] The crystal oscillator 10 outputs a reference signal used in wireless communication, etc. The crystal oscillator 10 is provided in the center of the substrate surface 3a, and is included in a first circuit component that is a noise source. The crystal oscillator 10 outputs a square wave (digital clock). This digital clock is supplied to the processing circuit chip 12 and the wireless chip 8 around the crystal oscillator 10 either directly or after frequency division. The digital clock contains many harmonic components, making it a likely noise source. However, since the wiring on the circuit board contains inductive components and capacitance components between the circuit board and ground, the harmonic components contained in the digital clock are reduced when the digital clock is transmitted to the surrounding area via the wiring. Furthermore, if a ferrite bead that blocks noise transmission is inserted in series with the wiring, the harmonic components contained in the digital clock can be further suppressed. In other words, the crystal oscillator 10 becomes a noise source by outputting a digital clock that contains many harmonic components. In addition, the second circuit components around the crystal oscillator 10 suppress the harmonic components contained in the digital clock, so they do not generate significant noise compared to the crystal oscillator 10. For this reason, the protruding conductors described below are positioned closer to the crystal oscillator 10 than the second circuit components.

[0033] It is also possible to generate a digital clock using a crystal unit and an oscillation circuit instead of the crystal oscillator 10. In such a configuration, noise may be generated from active elements (e.g., a C-MOS inverter) included in the oscillation circuit or from the wiring around the crystal unit. In this case, the crystal unit and the oscillation circuit can be treated as a single noise source. In addition, a crystal unit may be provided in addition to the crystal oscillator 10 to generate a carrier wave or the like used in wireless communication. If the carrier wave is a sine wave, the carrier wave contains few harmonic components. For this reason, noise countermeasures should be applied to the crystal oscillator 10 rather than to the crystal unit that outputs a sine wave.

[0034] The USB connectors 14 are an interface for connecting to external devices. The USB connectors 14 are arranged along the side edges of the circuit board 3. The USB connectors 14 are connectors that comply with the USB 3.0 standard or higher. The USB connectors 14 are included in the first circuit components that are noise sources. Noise generated by the USB connectors 14 may affect reception by the antenna 4. The LAN chip 13 is a chip for performing processing related to the LAN. The LAN chip 13 is also included in the first circuit components that are noise sources. The noise generated by the LAN chip 13 may affect reception by the antenna 4.

[0035] The wireless chip 8 is a chip that integrates functions for realizing wireless LAN communication. The wireless chip 8 constitutes a transceiver that transmits and receives wireless signals via the antenna 4. The wireless chip 8 is provided near the antenna 4. More specifically, the wireless chip 8 is provided at a position between the crystal oscillator 10 and the antenna 4 on the substrate surface 3a. The processing circuit chip 12 includes a processor etc. The processing circuit chip 12 has a function for controlling each part of the wireless communication device 1. The LAN connectors 16 are interfaces for connecting to external devices. Similar to the USB connectors 14, the LAN connectors 16 are arranged along the side edges of the circuit board 3. The wireless chip 8, the processing circuit chip 12, and the plurality of LAN connectors 16 are included in the second circuit component.

[0036] Like the mounted components, the antenna 4 is also provided on the board surface 3a of the circuit board 3. The antenna 4 is an antenna used for wireless LAN communication. The antenna 4 transmits radio waves to a terminal device with which the wireless communication device 1 performs wireless LAN communication, and receives radio waves from the terminal device. The antenna 4 has an antenna substrate 4a and an antenna pattern 4b. The antenna substrate 4a is a rigid substrate made of a dielectric material. The antenna substrate 4a is provided standing upright on the substrate surface 3a. The antenna substrate 4a is provided along the upper edge of the circuit board 3. The antenna pattern 4b is made of a conductor such as copper. The antenna pattern 4b is mounted on the substrate surface of the antenna substrate 4a. Antenna pattern 4b includes antenna element 4b1 and feed point 4b2. The elements included in antenna pattern 4b form an inverted-F antenna. Therefore, antenna 4 includes an inverted-F antenna.

[0037] The wireless module 2 of this embodiment further includes a first protruding conductor 20, a second protruding conductor 22, and a third protruding conductor 25. The first protruding conductor 20, the second protruding conductor 22, and the third protruding conductor 25 are provided on the board surface 3a of the circuit board 3. The first protruding conductor 20 is a protruding conductor provided in the vicinity of the crystal oscillator 10 . The first protruding conductor 20 is provided between the crystal oscillator 10 and the antenna 4. The first protruding conductor 20 is provided so as to sandwich the wireless chip 8 between itself and the antenna 4. In other words, the first protruding conductor 20 is provided at a position closer to the crystal oscillator 10 (first circuit component) than to the wireless chip 8 (second circuit component). The second protruding conductor 22 is a protruding conductor provided in the vicinity of the USB connector 14. When a plurality of USB connectors 14 are provided, the second protruding conductor 22 is preferably provided in the vicinity of the USB connector 14 that is closest to the antenna 4 among the plurality of USB connectors 14 .

[0038] The third protruding conductor 25 is a protruding conductor provided near the LAN chip 13 . The third protruding conductor 25 is provided between the LAN chip 13 and the antenna 4. The third protruding conductor 25 is provided so as to sandwich the wireless chip 8 between itself and the antenna 4. In other words, the third protruding conductor 25 is provided at a position closer to the crystal oscillator 10 than the wireless chip 8.

[0039] FIG. 2 is a plan view of the circuit board 3. As shown in FIG. For ease of understanding, Figure 2 shows only the antenna 4, crystal oscillator 10, USB connector 14, first protruding conductor 20, and second protruding conductor 22 among the components provided on the substrate surface 3a, and omits other components.

[0040] In the following description, the three mutually orthogonal directions in each drawing are referred to as the X direction, Y direction, and Z direction. Also, as shown in Fig. 2, one of the X directions is referred to as the X1 direction, and the opposite direction of the X1 direction is referred to as the X2 direction. One of the Y directions is referred to as the Y1 direction, and the opposite direction of the Y1 direction is referred to as the Y2 direction. One of the Z directions is referred to as the Z1 direction, and the opposite direction of the Z1 direction is referred to as the Z2 direction. In this embodiment, the board surface 3a of the circuit board 3 is parallel to the XY plane. The board surface 3a faces the Z1 direction. Each side of the circuit board 3 is parallel to the X direction or the Y direction.

[0041] Fig. 3 is a cross-sectional view of a main part of the circuit board 3. Fig. 3 shows a cross section of a portion of the circuit board 3 where the first protruding conductor 20 is provided. Fig. 3 is taken along the XZ cross section. Note that although only the first protruding conductor 20 will be described here, the second protruding conductor 22 also has a similar configuration to the first protruding conductor 20.

[0042] 3, the first protruding conductor 20 protrudes from the board surface 3a of the circuit board 3. The first protruding conductor 20 extends along the Z direction. The first protruding conductor 20 includes a conductor such as copper or aluminum alloy. The first protruding conductor 20 has a pin-shaped main body 24. The main body 24 may be a pin-shaped conductive material, or a pin-shaped resin whose surface is coated with a conductor. The main body 24 may also include a dielectric substrate and a strip-shaped conductor pattern formed on the dielectric substrate. In this case, the dielectric substrate on which the conductor pattern is formed is erected on the substrate surface 3a so that the longitudinal direction of the conductor pattern is aligned with the Z direction.

[0043] The first protruding conductor 20 has a base end 20a and a tip end 20b. The main body 24 extends from the base end 20a to the tip end 20b. The base end portion 20 a is connected to the board surface 3 a of the circuit board 3 . The circuit board 3 has a board main body 3p and a ground conductor 3g. The ground conductor 3g is a conductor pattern made of copper or the like provided on the back surface 3b of the circuit board 3. The ground conductor 3g is grounded. The back surface 3b is the surface of the circuit board 3 facing in the Z2 direction and is the surface opposite to the board surface 3a. The substrate body 3p has a substrate body surface 3p1 and a hole 3p2. The substrate body surface 3p1 is a surface of the substrate body 3p facing the Z1 direction. The hole 3p2 is a hole that penetrates the substrate body 3p. The hole 3p2 opens to the substrate body surface 3p1.

[0044] The base end 20a of the first protruding conductor 20 is inserted into the hole 3p2. In this manner, the base end 20a is fixed to the substrate surface 3a. The base end 20a is electrically connected to the ground conductor 3g by brazing, soldering, or the like. Therefore, the first protruding conductor 20 is grounded. As shown in FIG. 3, the tip end 20b of the first protruding conductor 20 is an electrically open end. Furthermore, the first protruding conductor 20 does not have a feeding point, etc. Therefore, the first protruding conductor 20 is a grounded, non-powered element.

[0045] As such, the first protruding conductor 20 has a base end 20a connected to the substrate surface 3a and a tip end 20b which is an open end, so that as long as there is at least space available to connect the base end 20a, additional first protruding conductors 20 can be mounted even after a large number of chips and circuits have been mounted on the circuit board 3.

[0046] Furthermore, since the first protruding conductor 20 has a pin-shaped main body 24 extending from the base end 20a to the tip end 20b, the space required to provide the first protruding conductor 20 on the substrate surface 3a can be minimized. Therefore, it becomes easier to mount additional first protruding conductors 20 after a large number of chips and circuits have been mounted on the circuit board 3.

[0047] As shown in FIG. 2, the first protruding conductor 20 is provided at a position closer to the crystal oscillator 10 than the antenna 4 when the substrate surface 3a is viewed from above. 2, the longitudinal direction of the antenna 4 is parallel to the Y direction. The longitudinal direction of the antenna 4 is the direction in which the antenna element 4b1 of the antenna 4 extends. The antenna substrate 4a is also parallel to the Y direction.

[0048] 2, an imaginary line L1 is a straight line on the substrate surface 3a that passes through the center point 10p of the crystal oscillator 10 and is perpendicular to the longitudinal direction of the antenna 4. The imaginary line L1 is perpendicular to the antenna 4. Therefore, the distance between the crystal oscillator 10 and the antenna 4 (antenna element 4b1) is minimum on the imaginary line L1. In FIG. 2, the center of the first protruding conductor 20 is located on the imaginary line L1. That is, the first protruding conductor 20 is provided on an imaginary line (passing line) L1 that passes through the crystal oscillator 10 and the antenna 4 and on which the distance between the crystal oscillator 10 and the antenna 4 is the shortest. The distance between the first protruding conductor 20 and the antenna 4 is also smallest on the imaginary line L1.

[0049] In FIG. 2, the distance s1 between the first protruding conductor 20 and the crystal oscillator 10 is the distance between the center of the first protruding conductor 20 and the center point 10p of the crystal oscillator 10. Furthermore, the distance w1 between the first protruding conductor 20 and the antenna 4 is the distance between the center of the first protruding conductor 20 and the feeding point 4b2. In other words, the distance w1 is the distance when the distance between the first protruding conductor 20 and the antenna 4 is minimum. In this embodiment, the distance s1 is shorter than the distance w1. Therefore, the first protruding conductor 20 is provided at a position closer to the crystal oscillator 10 than the antenna 4.

[0050] Here, the crystal oscillator 10 is a first circuit component that is a noise source. The noise from the crystal oscillator 10 may affect reception by the antenna 4. In contrast, in this embodiment, the first protruding conductor 20, which is provided in a position relatively close to the crystal oscillator 10, resonates due to noise from the crystal oscillator 10. Due to this resonance, the noise is absorbed by the first protruding conductor 20 and attenuated. As a result, with a simple configuration in which the first protruding conductor 20 is provided in the vicinity of the crystal oscillator 10, it is possible to reduce noise reaching the antenna 4 from the crystal oscillator 10. The noise referred to here refers to electromagnetic waves emitted in conjunction with the operation of a first circuit component that is a noise source, such as crystal oscillator 10, and includes the frequency band of radio waves transmitted and received by antenna 4.

[0051] If the distance s1 is shorter than the distance w1, noise reduction is possible, but the distance s1 may be set to 0.2 times or less the distance w1. If the distance s1 is greater than 0.2 times the distance w1, the distance between the crystal oscillator 10 and the protruding conductor 20 may decrease the noise absorption effect. By setting the distance s1 to 0.2 times the distance w1 or less, noise is effectively absorbed by the protruding conductor 20.

[0052] In the present embodiment, the first protruding conductor 20 is provided on the imaginary line L1, but the first protruding conductor 20 may be disposed at a position deviated from the imaginary line L1. FIG. 4 is a diagram showing a case where the first protruding conductor 20 is disposed at a position deviated from the imaginary line L1. 4, distance w1 is the distance between the center of the first protruding conductor 20 and point 4r. Point 4r is the point where imaginary line L5 and antenna element 4b1 intersect. Imaginary line L5 is a straight line on the substrate surface 3a that passes through the center of the first protruding conductor 20 and is parallel to the X direction. 4, the first protruding conductor 20 is also disposed at a position where the distance s1 is shorter than the distance w1. Therefore, the first protruding conductor 20 is disposed at a position closer to the crystal oscillator 10 than the antenna 4. This allows the first protruding conductor 20 to absorb noise from the crystal oscillator 10 while suppressing the influence of the first protruding conductor 20 on the antenna 4.

[0053] Returning to FIG. 2, the first protruding conductor 20 is preferably provided on the imaginary line L1, but the first protruding conductor 20 may also be disposed in the area A1 between the crystal oscillator 10 and the antenna 4. Area A1 is an area surrounded by a pair of imaginary lines L2 and L3 and the antenna 4. Imaginary line L2 is a straight line on the substrate surface 3a that passes through a first endpoint 4p of the antenna 4 and a center point 10p of the crystal oscillator 10. The first endpoint 4p is the endpoint of the antenna element 4b1 on the Y1 direction side. Imaginary line L3 is a straight line on the substrate surface 3a that passes through a second endpoint 4q of the antenna 4 and a center point 10p of the crystal oscillator 10. The second endpoint 4q is the endpoint of the antenna element 4b1 on the Y2 direction side.

[0054] The first protruding conductor 20 is disposed in a position within the region A1 that satisfies the condition that the distance s1 is shorter than the distance w1. When the first protruding conductor 20 is disposed in the region A1, the first protruding conductor 20 is disposed between the crystal oscillator 10 and the antenna 4. Therefore, the first protruding conductor 20 can absorb noise radiated from the crystal oscillator 10 toward the antenna 4, and can effectively reduce the noise reaching the antenna 4.

[0055] 3, the length h from the base end 20a to the tip end 20b of the first protruding conductor 20 may be 0.2 to 0.25 times the wavelength of the radio waves transmitted and received by the antenna 4. In other words, the length h may be approximately ¼ of the wavelength of the radio waves transmitted and received by the antenna 4. If the length of the first protruding conductor 20 is smaller than 0.2 times the wavelength of the wave transmitted and received by the antenna 4 or larger than 0.25 times, the resonant frequency of the first protruding conductor 20 will be significantly different from the frequency of the wave transmitted and received by the antenna 4, and there is a risk that noise generated by the crystal oscillator 10 that is close to the frequency of the wave transmitted and received by the antenna 4 will not be effectively absorbed by the first protruding conductor 20. By setting the length h to be 0.2 to 0.25 times the wavelength of the wave transmitted and received by the antenna 4, noise in the vicinity of the frequency of the wave transmitted and received by the antenna 4 is effectively absorbed by the first protruding conductor 20.

[0056] Furthermore, as described above, the first protruding conductor 20 can be additionally mounted. That is, the first protruding conductor 20 can be provided on the board surface 3a of the circuit board 3 on which the first protruding conductor 20 is not provided. This makes it possible to effectively reduce noise reaching the antenna 4.

[0057] As shown in FIG. 2, the USB connector 14 is provided at a position on the Y2 direction side of the antenna 4. In FIG. 2, the second end point 4q of the antenna 4 is the position of the antenna 4 that is closest to the USB connector 14. In FIG. 2, an imaginary line L4 is a straight line on the board surface 3a that passes through the center point 14p of the USB connector 14 and the second end point 4q of the antenna 4. Therefore, the distance between the USB connector 14 and the antenna 4 is minimum on the imaginary line L4. In FIG. 2, the center of the second protruding conductor 22 is located on the imaginary line L4. The second protruding conductor 22 is provided on an imaginary line (passing line) L4 that passes through the USB connector 14 and the antenna 4 and on which the distance between the USB connector 14 and the antenna 4 is the shortest. Therefore, the distance between the second protruding conductor 22 and the antenna 4 is also minimum on the imaginary line L4. The imaginary line L4 is a straight line on the substrate surface 3a.

[0058] In FIG. 2, the distance s2 between the second protruding conductor 22 and the USB connector 14 is the distance between the center of the second protruding conductor 22 and the center point 14p of the USB connector 14. The distance w2 between the second protruding conductor 22 and the antenna 4 is the distance between the center of the second protruding conductor 22 and the second end point 4q. In other words, the distance w2 is the distance when the distance between the first protruding conductor 20 and the antenna 4 is minimum. In this embodiment, the distance s2 is shorter than the distance w2. Therefore, the second protruding conductor 22 is provided at a position closer to the USB connector 14 than the antenna 4.

[0059] As described above, the USB connector 14 conforming to the USB 3.0 or higher standard is also a first circuit component that is a noise source, similar to the crystal oscillator 10. Noise from the USB connector 14 may affect reception by the antenna 4. In contrast, in this embodiment, the second protruding conductor 22, which is provided at a position relatively close to the USB connector 14, which is the first circuit component, resonates due to noise from the USB connector 14. Due to this resonance, the noise is absorbed by the second protruding conductor 22 and attenuated. As a result, similar to the first protruding conductor 20, by providing the second protruding conductor 22, it is possible to reduce noise reaching the antenna 4 from the USB connector 14.

[0060] In this embodiment, the second protruding conductor 22 is arranged on the virtual line L4, but if the distance s2 is shorter than the distance w2, the second protruding conductor 22 may be arranged at a position away from the virtual line L4.

[0061] The second protruding conductor 22 is preferably provided on the imaginary line L4, but the second protruding conductor 22 may be disposed in the area A2 between the USB connector 14 and the antenna 4. Area A2 is an area surrounded by a pair of imaginary lines L4 and L6 and the antenna 4. As described above, imaginary line L4 is a straight line that passes through the second end point 4q and the center point 14p of the USB connector 14. Imaginary line L6 is a straight line on the board surface 3a that passes through the first end point 4p and the center point 14p. The second protruding conductor 22 is disposed in the region A2 at a position that satisfies the condition that the distance s2 is shorter than the distance w2.

[0062] In this case as well, the second protruding conductor 22 is disposed between the USB connector 14 and the antenna 4. Therefore, the second protruding conductor 22 can absorb noise radiated from the USB connector 14 toward the antenna 4, and can effectively reduce the noise reaching the antenna 4.

[0063] 2, the first protruding conductor 20 and the second protruding conductor 22 are described, but the third protruding conductor 25 provided near the LAN chip 13 is also arranged in the same configuration as the first protruding conductor 20 and the second protruding conductor 22. Therefore, the third protruding conductor 25 can absorb noise radiated from the LAN chip 13, and can effectively reduce noise reaching the antenna 4.

[0064] [Regarding the second embodiment] FIG. 5 is a partial perspective view showing an example of a wireless communication device 1 according to the second embodiment. This embodiment differs from the first embodiment in that a plurality of first protruding conductors 20 are provided around the periphery of the crystal oscillator 10.

[0065] 5, in this embodiment, four first protruding conductors 20 are provided. The four first protruding conductors 20 are arranged on a circle centered at the center point 10p of the crystal oscillator 10. The four first protruding conductors 20 are provided at positions in the X direction and at positions in the Y direction relative to the center point 10p.

[0066] 5, the four first protruding conductors 20 surround the periphery of the crystal oscillator 10. The four first protruding conductors 20 are provided so as to surround the crystal oscillator 10. This allows the four first protruding conductors 20 to absorb noise radiated from the crystal oscillator 10 to the surrounding area, and the noise reaching the antenna 4 can be reduced more effectively.

[0067] In this embodiment, four first protruding conductors 20 are provided, but three or more first protruding conductors 20 may be provided. Furthermore, when the first protruding conductors 20 have a shape that extends in a direction along the substrate surface 3a, such as a plate shape as will be described in a third embodiment, the multiple first protruding conductors 20 may surround the periphery of the crystal oscillator 10. In this case, the crystal oscillator 10 is located within an area on the substrate surface 3a that is formed by connecting the ends of a pair of adjacent first protruding conductors 20 with a straight line. The end of the first protruding conductor 20 refers to the end of the first protruding conductor 20 in the direction along the substrate surface 3a. In other words, when the crystal oscillator 10 is positioned within the region, the multiple first protruding conductors 20 surround the periphery of the crystal oscillator 10. Therefore, a pair of first protruding conductors 20 may surround the periphery of the crystal oscillator 10.

[0068] [Regarding the third embodiment] FIG. 6 is a partial perspective view showing an example of a wireless communication device 1 according to the third embodiment. This embodiment differs from the first embodiment in that one plate-shaped first protruding conductor 20 is provided.

[0069] The main body 24 of the first protruding conductor 20 of this embodiment has a rectangular plate shape extending from the base end 20a to the tip end 20b. The main body 24 may be a plate made of a conductive material, or may be a plate made of resin with a conductor coated on its surface. The first protruding conductor 20 is provided at a predetermined interval on the X1 direction side of the crystal oscillator 10. Therefore, the distance (s1) between the first protruding conductor 20 and the crystal oscillator 10 is shorter than the distance (w1) between the first protruding conductor 20 and the antenna 4. The plate longitudinal direction of the first protruding conductor 20 is parallel to the Y direction. The plate lateral direction of the first protruding conductor 20 is parallel to the Z direction. The first protruding conductor 20 of this embodiment has a larger width in the direction parallel to the substrate surface 3a than, for example, a pin-shaped conductor, and therefore can absorb noise while blocking noise from the crystal oscillator 10.

[0070] [Regarding the Fourth Embodiment] FIG. 7 is a partial perspective view showing an example of a wireless communication device 1 according to the fourth embodiment. This embodiment differs from the first embodiment in that a plurality of first protruding conductors 20 are arranged in a row.

[0071] A plurality of first protruding conductors 20 (seven in the illustrated example) are arranged in a row on the X1 direction side of the crystal oscillator 10 so as to be parallel to the Y direction. The distance (s1) between each first protruding conductor 20 and the crystal oscillator 10 is shorter than the distance (w1) between the first protruding conductor 20 and the antenna 4.

[0072] Even when multiple first protruding conductors 20 are arranged in a row as in this embodiment, the multiple first protruding conductors 20 can absorb noise while blocking noise from the crystal oscillator 10.

[0073] [Regarding the fifth embodiment] FIG. 8 is a partial perspective view showing an example of a wireless communication device 1 according to the fifth embodiment. This embodiment differs from the first embodiment in that the first protruding conductor 20 has an L-shape.

[0074] In FIG. 8, the main body 24 of the first protruding conductor 20 has a protruding portion 26 and a horizontally extending portion 28. The protrusion 26 is a rod-shaped portion that extends from the base end 20a along the Z1 direction that intersects with the substrate surface 3a. The horizontal extension portion 28 is a rod-shaped portion that extends along the XY plane from the tip of the protrusion 26 to the tip portion 20b. The horizontal extension portion 28 in this embodiment extends parallel to the Y direction. The first protruding conductor 20 of this embodiment is configured to have an L-shape by the protruding portion 26 and the horizontal extending portion 28.

[0075] The length from the base end portion 20a to the tip end portion 20b is the same as in the first embodiment. In this case, the horizontally extending portion 28 can ensure the necessary length of the first protruding conductor 20 while keeping the protruding height from the circuit board 3 low.

[0076] [Regarding the Sixth Embodiment] FIG. 9 is a partial perspective view showing an example of a wireless communication device 1 according to the sixth embodiment. This embodiment differs from the first embodiment in that the first protruding conductor 20 has a gate shape.

[0077] In FIG. 9, the first protruding conductor 20 has a first end 20c, a second end 20d, and a main body 30. The first end 20c is an end of the first protruding conductor 20, and is an end that is connected to the first point 3a1 on the substrate surface 3a. The second end 20d is an end of the first protruding conductor 20, and is an end that is connected to the second point 3a2 on the substrate surface 3a. The first point 3a1 is located on the X2 side of the crystal oscillator 10 and on the Y2 side of the crystal oscillator 10. The second point 3a2 is located on the X1 side of the crystal oscillator 10 and on the Y1 side of the crystal oscillator 10. The main body 30 is a rod-shaped member that connects the first end 20c and the second end 20d.

[0078] The main body portion 30 has a first protruding portion 32, a second protruding portion 34, and a transversely extending portion 36. The first protrusion 32 is a rod-shaped portion that protrudes in the Z1 direction from the first end 20c. The second protrusion 34 is a rod-shaped portion that protrudes in the Z1 direction from the second end 20d. The first protrusion 32 and the second protrusion 34 extend along the Z direction. The first end 20c and the second end 20d are electrically connected to the ground conductor portion 3g (FIG. 3) by brazing, soldering, etc., similar to the base end 20a of the first embodiment, so that both ends of the first protruding conductor 20 are grounded. The laterally extending portion 36 is a rod-shaped portion that connects the tip of the first protruding portion 32 and the tip of the second protruding portion 34. The laterally extending portion 36 in this embodiment extends parallel to the Y direction. The first protruding conductor 20 of this embodiment has a gate shape formed by a first protruding portion 32, a second protruding portion , and a horizontally extending portion .

[0079] In this embodiment, the first protruding conductor 20 has a shape that connects the portions protruding from both the first point 3a1 and the second point 3a2, so that one protruding conductor can achieve the same effect as when two protruding conductors are provided protruding from one location on the substrate surface 3a. Furthermore, in this embodiment, by providing the horizontally extending portion 36, the length required for the first protruding conductor 20 can be ensured while the protruding height from the circuit board 3 can be kept low.

[0080] The length from the first end 20c to the second end 20d of the first protruding conductor 20 may be 0.4 to 0.5 times the wavelength of the wave transmitted and received by the antenna 4. In other words, the length from the first end 20c to the second end 20d of the first protruding conductor 20 may be approximately ½ the wavelength of the wave transmitted and received by the antenna 4. If the length of the first protruding conductor 20 is smaller than 0.4 times the wavelength of the wave transmitted and received by the antenna 4 or larger than 0.5 times, the resonant frequency of the first protruding conductor 20 will be significantly different from the frequency of the wave transmitted and received by the antenna 4, and there is a risk that noise generated by the crystal oscillator 10 that is close to the frequency of the wave transmitted and received by the antenna 4 will not be effectively absorbed by the first protruding conductor 20. By setting the length h to be 0.4 to 0.5 times the wavelength of the wave transmitted and received by the antenna 4, noise in the vicinity of the frequency of the wave transmitted and received by the antenna 4 is effectively absorbed by the first protruding conductor 20.

[0081] [Regarding the Seventh Embodiment] FIG. 10 is a partial perspective view showing an example of a wireless communication device 1 according to the seventh embodiment. This embodiment differs from the second embodiment in that the plurality of first protruding conductors 20 include a first conductor 40 and a second conductor 42. Furthermore, the antenna 4 included in the wireless communication device 1 of this embodiment is capable of transmitting and receiving a first radio wave having a first wavelength, and is also capable of transmitting and receiving a second radio wave having a second wavelength that is longer than the first wavelength.

[0082] 10, the plurality of first protruding conductors 20 includes four first conductors 40 and four second conductors 42. The first conductors 40 and the second conductors 42 are arranged alternately around the periphery of the crystal oscillator 10. The length from the base end to the tip end of the first conductor 40 and the length from the base end to the tip end of the second conductor 42 are different.

[0083] In this case, the resonant frequency of the first conductor 40 is different from the resonant frequency of the second conductor 42. Therefore, when the antenna 4 transmits and receives two radio waves with different frequencies, by setting the resonant frequency of the first conductor to a value corresponding to the first radio wave and the resonant frequency of the second conductor to a value corresponding to the second radio wave, it is possible to have the first conductor 40 and the second conductor 42 absorb noise for each of the two radio waves.

[0084] More specifically, the length of the first conductor 40 is 0.2 to 0.25 times the first wavelength, and the length of the second conductor 42 is 0.2 to 0.25 times the second wavelength. As a result, noise in the vicinity of the frequency of the first radio wave transmitted and received by the antenna 4 is effectively absorbed by the first conductor 40, and noise in the vicinity of the frequency of the second radio wave is effectively absorbed by the second conductor 42.

[0085] [About verification testing] Next, a verification test conducted to examine the effects of this embodiment will be described. The test method involved constructing a model of the antenna 4, the first protruding conductor 20, the noise source, and the circuit board 3 on which they were mounted, and using this model to determine the effect of noise from the noise source on the antenna 4 by computer simulation. The frequencies of the waves transmitted and received by the antenna 4 were in the frequency band from 2.4 GHz to 2.5 GHz or the frequency band from 5 GHz to 5.5 GHz.

[0086] Fig. 11 shows an example of a model used in a verification test, in which (a) in Fig. 11 shows a perspective view of the model, and (b) in Fig. 11 shows a side view of the model as viewed from the Y1 direction. On the substrate surface 3a of the model, the crystal oscillator 10 shown in each of the above embodiments was replaced with a noise source N, and an antenna 4 (antenna pattern 4b), a first protruding conductor 20 (hereinafter simply referred to as the protruding conductor 20), and the noise source N were arranged.

[0087] 11, the antenna 4 is arranged along the Y direction. The noise source N is arranged on an imaginary line L1. The imaginary line L1 is a straight line that passes through the feed point 4b2 and is parallel to the X direction. The distance w shown in (b) of Figure 11 was set to 60 mm. The length n was set to 3 mm. The distance w is the distance between the noise source N and the antenna 4 along the X direction. The length n is the length of the noise source N in the Z direction. 11, the distance s and length h were set appropriately. The distance s is the distance between the noise source N and the protruding conductor 20 in the XY plane. The length h is the length from the base end to the tip end of the protruding conductor 20. The diameter of the protruding conductor 20 was set to 0.5 mm.

[0088] The above model was used to determine the transmission characteristics from noise source N to antenna 4. The transmission characteristics from noise source N to antenna 4 were determined as follows. That is, the frequency characteristics of S21, which is an S parameter when the power feed point of noise source N in the model is set to port 1 and the power feed point 4b2 of antenna 4 is set to port 2, were determined as the transmission characteristics from noise source N to antenna 4. Regarding the influence of noise from the noise source N on the antenna 4, the frequency characteristics of S21 were determined for each of the following examples and comparatively evaluated.

[0089] Example 1 As a model of Example 1, a model including one protruding conductor 20 was constructed. In the model of Example 1, the position of the protruding conductor 20 may be on the virtual line L1 and on the X1 direction side of the noise source N as shown in FIG. 11 , or on the virtual line L1 and on the X2 direction side of the noise source N as shown in FIG. 2 . Example 1, in which the protruding conductor 20 is on the virtual line L1 and on the X2 direction side of the noise source N, is a model corresponding to the first embodiment. Example 1, in which the protruding conductor 20 is on the virtual line L1 and on the X1 direction side of the noise source N, is a model corresponding to a modified example of the first embodiment. Example 2 As a model of Example 2, a model including two protruding conductors 20 was constructed. In Example 2, two protruding conductors 20 were provided on the imaginary line L1 (FIG. 11). The two protruding conductors 20 were provided so as to sandwich the noise source N, as shown in FIG. 12. The distance s between the two protruding conductors 20 was 5 mm, and the length h was 25 mm. Example 3 A model including four protruding conductors 20 was constructed as a model of Example 3. The four protruding conductors 20 were provided around the noise source N, as shown in (a) of Fig. 13. The four protruding conductors 20 were provided at four points in the X and Y directions of the noise source N. The distance s between the four protruding conductors 20 was 5 mm, and the length h was 20 mm. Example 4 A model including eight protruding conductors 20 was constructed as a model of Example 3. The eight protruding conductors 20 were provided around the noise source N, as shown in (b) of FIG. 13. The eight protruding conductors 20 were provided at four points in the X and Y directions of the noise source N, as well as at midpoints between adjacent points among the four points. The distance s between the eight protruding conductors 20 was 5 mm, and the length h was 20 mm.

[0090] Example 5 A model including 12 protruding conductors 20 was constructed as a model of Example 5. The 12 protruding conductors 20 were provided around the noise source N, as shown in (c) of FIG. 13. The 12 protruding conductors 20 were provided at four points in the X and Y directions of the noise source N, as well as at two points that divide the distance between adjacent points in the four directions into thirds. The distance s between the 12 protruding conductors 20 was 5 mm, and the length h was 20 mm. Example 6 A model including a protruding conductor 20 having a rectangular plate shape was constructed as a model of Example 6. The model of Example 6 corresponds to the above-mentioned third embodiment. As shown in FIG. 14(a), the distance s between the protruding conductor 20 and the noise source N in the X direction was 5 mm, the longitudinal dimension b in the Y direction was 30 mm, and the length h was 20 mm. Example 7 A model including a plurality of protruding conductors 20 arranged in a line was constructed as the model of Example 7. The model of Example 7 corresponds to the above-mentioned fourth embodiment. As shown in (b) of Fig. 14, this model includes eleven protruding conductors 20. The eleven protruding conductors 20 are arranged in a row along the Y direction. The distance x along the X direction between the row of protruding conductors 20 and the noise source N is 5 mm, the spacing c between adjacent pairs of protruding conductors 20 is 3 mm, and the length h of the eleven protruding conductors 20 is 20 mm. Example 8 A model including an L-shaped protruding conductor 20 was constructed as a model of Example 8. The model of Example 8 corresponds to the above-mentioned fifth embodiment. As shown in (a) and (b) of FIG. 15, the distance s was 5 mm, the length h of the protruding conductor 20 was 10 mm, and the longitudinal dimension j of the horizontal extension portion 28 was 10 mm. In the model of Example 8, as shown in FIG. 15(b), the positions and orientations of the protruding conductors 20 were set to the following four types. Position P1: The protrusion 26 is located on a straight line extending from the noise source N in the X1 direction, and the orientation of the horizontal extension 28 is along the Y direction. Position P2: The protrusion 26 is located on a line extending from the noise source N in the Y1 direction, and the direction of the horizontal extension 28 is along the X direction. Position P3: The protrusion 26 is located on a line extending from the noise source N in the X2 direction, and the orientation of the horizontal extension 28 is along the Y direction. Position P4: The protrusion 26 is located on a line extending from the noise source N in the Y2 direction, and the orientation of the horizontal extension 28 is along the X direction.

[0091] Example 9 A model including a gate-shaped protruding conductor 20 was constructed as a model of Example 9. The model of Example 9 corresponds to the sixth embodiment described above. As shown in FIG. 16(a), the length h of the protruding conductor 20 was set to 10 mm, and the longitudinal dimension j of the horizontal extension portion 28 was set to 20 mm. In the model of Example 9, the positions of the protruding conductors 20 were set to the following four types. Position P11: A position where the lateral extension portion 36 is arranged along the Y direction and is arranged on the X1 direction side of the noise source N. Position P12: A position where the lateral extension portion 36 is arranged along the X direction and is arranged in the Y1 direction of the noise source N. Position P13: A position where the lateral extension portion 36 is arranged along the Y direction and is arranged in the X2 direction of the noise source N. Position P14: A position where the lateral extension portion 36 is arranged along the X direction and is arranged in the Y2 direction of the noise source N. Example 10 A model was constructed as Example 10, in which the protruding conductor 20 has a pin-shaped main body portion and a plate-shaped conductor portion provided on the main body portion. The model of Example 10 corresponds to a modified example of the first embodiment described above. As shown in FIG. 17( a ), the protruding conductor 20 has a main body portion 50 and a plate-shaped conductor portion 52 . The main body 50 is a pin-shaped member extending in the Z1 direction from the substrate surface 3a. The plate-shaped conductor 52 is provided at the end of the main body 50 located on the tip 20b side. The plate-shaped conductor 52 has a circular shape. The tip of the main body 50 is fixed to the center of the plate-shaped conductor 52. The plate-shaped conductor 52 is parallel to the substrate surface 3a. In this embodiment, by providing the plate-like conductor portion 52, an appropriate capacitance component can be added to the tip end of the protruding conductor 20, and the noise absorption effect can be maintained even if the length of the main body portion 50 is shortened. As a result, the protruding conductor 20 can be made smaller. The diameter r of the plate-shaped conductor portion 52 was 6 mm, the thickness of the plate-shaped conductor portion 52 was 0.5 mm, and the length h of the protruding conductor 20 was 10 mm. Example 11 A model in which the protruding conductor 20 has a main body portion with a spiral shape was constructed as a model of Example 11. The model of Example 11 corresponds to a modified example of the first embodiment described above. 18, the protruding conductor 20 has a main body 54. The main body 54 has a spiral shape extending in the Z direction from the base end 20a to the tip end 20b. In this embodiment, the protruding conductor 20 has a spiral shape, so that the protruding height from the circuit board 3 can be kept low while the necessary length of the protruding conductor 20 is ensured. The diameter k of the main body 54 was 3.5 mm, and the length h of the protruding conductor 20 was 10 mm.

[0092] Comparison example As a comparative example, a model was constructed in which the protruding conductor 20 included in the first embodiment was eliminated.

[0093] [Regarding the length h of the protruding conductor 20] Fig. 19 is a diagram showing the frequency characteristics of S21 when the length of the protruding conductor 20 is changed using Example 1. In Fig. 19, the horizontal axis represents frequency and the vertical axis represents S21. Here, a model was used in which the protruding conductor 20 was provided on a line extending from the noise source N in the X1 direction. The distance s was set to 5 mm. The frequency of the wave transmitted and received by the antenna 4 was set to a frequency band from 2.4 GHz to 2.5 GHz. The length h was set to three values: 15 mm, 20 mm, and 25 mm.

[0094] In FIG. 19, the solid line indicates the graph for the comparative example, the one-dot chain line indicates the graph for length h=15 mm, the broken line indicates the graph for length h=20 mm, and the two-dot chain line indicates the graph for length h=25 mm. 19, the frequency characteristics of the three Examples 1 appear to be lower than the frequency characteristics of the Comparative Example in a wide frequency band including the frequency band of the waves transmitted and received by the antenna 4. This shows that noise in Example 1, which is provided with the protruding conductor 20, is reduced compared to the Comparative Example. In particular, when the length h is 25 mm, a noise reduction of about 10 dB is observed in the frequency band of the waves transmitted and received by the antenna 4 compared to the comparative example.

[0095] When the length h=25 mm, if the frequency of the waves transmitted and received by the antenna 4 is 2.4 GHz, the length h is 0.2 times the wavelength of the waves transmitted and received by the antenna 4. Also, if the frequency of the waves transmitted and received by the antenna 4 is 2.5 GHz, the length h is 0.21 times the wavelength of the waves transmitted and received by the antenna 4.

[0096] Fig. 20 is a diagram showing the frequency characteristics of S21 in Example 1. In Fig. 20, the horizontal axis represents frequency, and the vertical axis represents S21. Here, a model was used in which the protruding conductor 20 was provided on a line extending from the noise source N in the X1 direction. The distance s was set to 5 mm. The frequency of the transmission and reception waves of the antenna 4 was set to a frequency band from 5 GHz to 5.5 GHz. The length h was set to 12.7 mm.

[0097] In FIG. 20, the solid line indicates the graph for the comparative example, and the dashed dotted line indicates the graph for the length h=12.7 mm. 20, the frequency characteristics of Example 1, in which the protruding conductor 20 is provided, appear to be lower than the frequency characteristics of the comparative example in a wide frequency band including the frequency band of the waves transmitted and received by the antenna 4. This shows that the noise of Example 1, in which the protruding conductor 20 is provided, is reduced compared to the comparative example.

[0098] When the length h = 12.7 mm, if the frequency of the waves transmitted and received by the antenna 4 is 5 GHz, the length h is 0.21 times the wavelength of the waves transmitted and received by the antenna 4. Also, if the frequency of the waves transmitted and received by the antenna 4 is 5.5 GHz, the length h is 0.23 times the wavelength of the waves transmitted and received by the antenna 4.

[0099] From the results of Figures 19 and 20, it can be seen that noise from noise source N is effectively absorbed by protruding conductor 20 when length h is set to be greater than or equal to 0.2 times and less than or equal to 0.25 times the wavelength of the wave transmitted and received by antenna 4.

[0100] [Regarding the distance s between the protruding conductor 20 and the noise source N] 21 is a diagram showing the frequency characteristics of S21 when the distance s between the noise source N and the protruding conductor 20 is changed using Example 1. In Fig. 21, the horizontal axis represents frequency and the vertical axis represents S21. Here, a model was used in which the protruding conductor 20 was provided on a line extending from the noise source N in the X1 direction. The length h was set to 20 mm. The frequency of the waves transmitted and received by the antenna 4 was set to a frequency band from 2.4 GHz to 2.5 GHz. The distance s was set to two values: 5 mm and 10 mm.

[0101] In FIG. 21, the solid line indicates the graph for the comparative example, the dashed line indicates the graph for the distance s=5 mm, and the broken line indicates the graph for the distance s=10 mm. As shown in FIG. 21, the frequency characteristics of the two first examples in which the protruding conductor 20 is provided appear to be lower than the frequency characteristics of the comparative example in a wide frequency band including the frequency band of the waves transmitted and received by the antenna 4. Moreover, the frequency characteristics of Example 1 where the distance s = 5 mm appear lower than the frequency characteristics of Example 1 where the distance s = 10 mm over a wide frequency band, which shows that Example 1 where the distance s = 5 mm has a greater noise reduction effect than Example 1 where the distance s = 10 mm.

[0102] 22 is another diagram showing the frequency characteristics of S21 when the distance s between the noise source N and the protruding conductor 20 is changed using Example 1. In Fig. 22, the horizontal axis represents frequency and the vertical axis represents S21. Here, a model was used in which the protruding conductor 20 was provided on a line extending from the noise source N in the X2 direction. In other words, the protruding conductor 20 was provided between the noise source N and the antenna 4. The length h was set to 20 mm. The frequency of the waves transmitted and received by the antenna 4 was set to a frequency band from 2.4 GHz to 2.5 GHz. The distance s was set to three values: 5 mm, 15 mm, and 25 mm.

[0103] In FIG. 22, the solid line indicates the graph for the comparative example, the one-dot chain line indicates the graph for distance s=5 mm, the broken line indicates the graph for distance s=15 mm, and the two-dot chain line indicates the graph for distance s=25 mm. 22, the frequency characteristics of Example 1 when the distance s=15 mm and Example 1 when the distance s=25 mm are higher than the frequency characteristics of the comparative example over a wide frequency band. This result indicates that Example 1 when the distance s=15 mm and Example 1 when the distance s=25 mm may not be able to achieve a noise reduction effect. The frequency characteristics of Example 1 where the distance s=5 mm appear lower than the frequency characteristics of Example 1 where the distance s=10 mm over a wide frequency band.

[0104] From the results of FIGS. 21 and 22, it can be said that the noise reduction effect of the protruding conductor 20 can be appropriately obtained by setting the distance s to approximately 12 mm or less. In other words, the distance s should be set to 0.2 times or less the distance w between the noise source N and the antenna 4. This allows the protruding conductor 20 to adequately achieve the effect of reducing noise.

[0105] [Electromagnetic field distribution and radiation pattern near noise sources] Fig. 23 is a diagram showing an image of the electromagnetic field distribution near noise source N. Fig. 23 shows an image of the electromagnetic field distribution when the model is viewed from the Y1 direction side. Note that the portion where the electromagnetic field intensity appears higher on the Z2 direction side of circuit board 3 is the electromagnetic field distribution generated by the power supply line of noise source N, and is not related to this test.

[0106] FIG. 23(a) is an image diagram of the electromagnetic field distribution of the comparative example. 23(b) is an image diagram of the electromagnetic field distribution in Example 1. The distance s was set to 5 mm, and the length h was set to 25 mm. FIG. 23(c) is an image diagram of the electromagnetic field distribution in the second embodiment.

[0107] As shown in FIG. 23(b), in Example 1, the protruding conductor 20 resonates, the noise from the noise source N is absorbed, and the range of the noise in the direction of the XY plane is reduced. 23(c) is the same as FIG. 23(b). In Example 2, it can be seen that the two protruding conductors 20 resonate, the noise from the noise source N is absorbed, and the range of the noise in the XY plane direction is reduced. In Example 2, the range of the noise is smaller than in Example 1.

[0108] 24 and 25 are diagrams showing the radiation pattern of the noise source N. FIG. Fig. 24 shows the radiation pattern when viewed from the Y2 direction on the XZ plane. Fig. 24 shows the radiation pattern in a coordinate system based on the X axis along the X1 direction, the Y axis along the Y1 direction, and the Z axis along the Z1 direction. The origin of this coordinate system is the position of the noise source N on the substrate surface 3a. Figure 24 shows the gain when the elevation angle is in the range of -180° to 180° when the azimuth angle is Φ = 0°. The elevation angle θ is the angle with respect to the Z axis. The azimuth angle Φ is the angle with respect to the X axis. Therefore, in Figure 24, the direction of the elevation angle θ = -90° is the direction facing toward antenna 4, and the direction of the elevation angle θ = 90° is the opposite direction toward antenna 4. In FIG. 24, the solid line indicates the vertically polarized wave component, and the dashed dotted line indicates the horizontally polarized wave component.

[0109] The diagram on the left in Fig. 24 shows the radiation pattern of the comparative example shown in Fig. 23. The diagram on the right in Fig. 24 shows the radiation pattern of Example 1 shown in Fig. 23. In FIG. 24, when the gain of the vertical polarization component in the directions of elevation angles θ=−90° and 90° is compared between the comparative example and Example 1, the gain of Example 1 is smaller than the gain of Comparative Example 1. Moreover, the gain of Example 1 is smaller than the gain of Comparative Example 1 in the range of elevation angle θ=−90° to 0° and in the range of elevation angle θ=0° to 90°.

[0110] 25 shows the radiation pattern when the XY plane is viewed from the Z1 direction side, and is shown in the same coordinate system as in FIG. 25 shows the gain in the range of azimuth angles Φ=-180° to 180° when the elevation angle θ=90°. Therefore, in FIG. 25, the direction of azimuth angle Φ=180° (-180°) is the direction facing the antenna 4 side. In FIG. 25, the solid line indicates the vertically polarized wave component, and the dashed dotted line indicates the horizontally polarized wave component.

[0111] The diagram on the left in Fig. 25 shows the radiation pattern of the comparative example shown in Fig. 23. The diagram on the right in Fig. 25 shows the radiation pattern of Example 1 shown in Fig. 23. 25, when the gain of the vertical polarization component is compared between the comparative example and example 1, the gain of example 1 is smaller than the gain of comparative example 1. Over the entire range of azimuth angles Φ=-180° to 180°, the gain of example 1 is smaller than the gain of comparative example 1. Therefore, even in the direction toward antenna 4, the gain of example 1 is smaller than the gain of comparative example 1.

[0112] 24 and 25, it can be seen that the area on the board surface 3a affected by the noise from the noise source N is reduced by the protruding conductor 20.

[0113] [Position of the protruding conductor 20 relative to the noise source N] Fig. 26 is a diagram showing the frequency characteristics of S21 when the position of the protruding conductor 20 is changed using Example 1. In Fig. 26, the horizontal axis represents frequency and the vertical axis represents S21. Here, the positions of the protruding conductors 20 were set in the following four ways. Position P21: Position on a line extending from noise source N in the X1 direction Position P22: Position on a line extending from the noise source N in the Y1 direction Position P23: Position on a line extending from noise source N in the X2 direction Position P24: Position on a line extending from noise source N in the Y2 direction

[0114] For each of positions P21 to P24, the length h was set to 20 mm and the distance s was set to 5 mm.

[0115] In FIG. 26, the thick solid line is a graph for the comparative example, the one-dot chain line is a graph for position P21, the broken line is a graph for position P22, the two-dot chain line is a graph for position P23, and the thin solid line is a graph for position P24. As shown in FIG. 26, the frequency characteristics of the four working examples 1 provided with the protruding conductor 20 appear to be lower than the frequency characteristics of the comparative example in a wide frequency band including the frequency band of the waves transmitted and received by the antenna 4. In particular, the frequency characteristics at position P23 appear to be lower than the frequency characteristics of the other three first embodiment examples.

[0116] The protruding conductor 20 of the first embodiment at the position P23 is provided between the noise source N and the antenna 4. From this result, it can be seen that the protruding conductor 20, when placed between the noise source N and the antenna 4, can effectively reduce the noise that reaches the antenna 4.

[0117] [Number of protruding conductors 20] Fig. 27 is a diagram showing the frequency characteristics of S21 when the number of protruding conductors 20 is changed. In Fig. 27, the horizontal axis represents frequency and the vertical axis represents S21. Here, by using Examples 1, 3, 4, and 5, the number of protruding conductors 20 was set to four, ie, 1, 4, 8, and 12. The protruding conductor 20 in Example 1 was provided on a straight line extending in the X1 direction from the noise source N. In Example 1, the distance s was 5 mm and the length h was 25 mm.

[0118] In FIG. 27, the thick solid line is the graph for the comparative example, the dotted line is the graph for Example 1 (1 line), the dashed line is the graph for Example 3 (4 lines), the two-dotted line is the graph for Example 4 (8 lines), and the thin solid line is the graph for Example 5 (12 lines). As shown in FIG. 27, there is a tendency that the frequency characteristics appear lower as the number of protruding conductors 20 increases.

[0119] Fig. 28 is a diagram showing an image of the electromagnetic field distribution in the vicinity of the noise source N. Fig. 28 shows an image of the electromagnetic field distribution when the model is viewed from the Z1 direction side. (a) in Fig. 28 is an image diagram of the electromagnetic field distribution of a comparative example. (b) in Fig. 28 is an image diagram of the electromagnetic field distribution of Example 1. (c) in Fig. 28 is an image diagram of the electromagnetic field distribution of Example 3. (d) in Fig. 28 is an image diagram of the electromagnetic field distribution of Example 4. (e) in Fig. 28 is an image diagram of the electromagnetic field distribution of Example 5. As shown in FIG. 28, it can be seen that the greater the number of protruding conductors 20, the smaller the range of noise in the XY plane tends to be.

[0120] 27 and 28, it can be seen that if a plurality of protruding conductors 20 are provided so as to surround the noise source N, the noise reaching the antenna 4 can be reduced more effectively. 27 and 28, it can be seen that the greater the number of protruding conductors 20 surrounding the noise source N, the greater the noise reduction effect.

[0121] [Regarding the protruding conductor 20 having a rectangular plate shape] Fig. 29 is a diagram showing the frequency characteristics of S21 in Example 6. In Fig. 29, the horizontal axis represents frequency, and the vertical axis represents S21. In FIG. 29, the solid line is the graph for the comparative example, and the two-dot chain line is the graph for Example 6. 29, the frequency characteristics of Example 6 having the rectangular plate-shaped protruding conductor 20 appear to be lower than the frequency characteristics of the comparative example in a wide frequency band including the frequency band of the waves transmitted and received by the antenna 4. This shows that the noise of Example 6 is reduced compared to the comparative example.

[0122] [Regarding multiple protruding conductors 20 arranged in a row] Fig. 30 is a diagram showing the frequency characteristics of S21 in Example 7. In Fig. 30, the horizontal axis represents frequency, and the vertical axis represents S21. In FIG. 30, the solid line is the graph for the comparative example, and the two-dot chain line is the graph for Example 7. 30, the frequency characteristics of Example 7 having a plurality of protruding conductors 20 arranged in a row appear lower than the frequency characteristics of the comparative example over a wide frequency band including the frequency band of the waves transmitted and received by the antenna 4. This shows that the noise of Example 7 is reduced compared to the comparative example.

[0123] [Regarding the L-shaped protruding conductor 20] Fig. 31 is a diagram showing the frequency characteristics of S21 in Example 8. In Fig. 31, the horizontal axis represents frequency, and the vertical axis represents S21. In FIG. 31, the thick solid line is a graph for the comparative example, the one-dot chain line is a graph for position P1, the broken line is a graph for position P2, the two-dot chain line is a graph for position P3, and the thin solid line is a graph for position P4.

[0124] 31, the frequency characteristics of the four examples 8 having the L-shaped protruding conductor 20 appear to be lower than the frequency characteristics of the comparative example in a wide frequency band including the frequency band of the waves transmitted and received by the antenna 4. This shows that the noise of the example 8 is reduced compared to the comparative example. In particular, the frequency characteristics at position P3 appear to be lower than the frequency characteristics of the other three examples 8. The protruding conductor 20 at position P3 of example 8 is provided between the noise source N and the antenna 4. From this result, it can be seen that even in the case of the L-shaped protruding conductor 20, by being disposed between the noise source N and the antenna 4, the noise reaching the antenna 4 can be effectively reduced.

[0125] [Regarding the gate-shaped protruding conductor 20] Fig. 32 is a diagram showing the frequency characteristics of S21 in Example 9. In Fig. 32, the horizontal axis represents frequency, and the vertical axis represents S21. In FIG. 32, the thick solid line is a graph for the comparative example, the one-dot chain line is a graph for position P11, the broken line is a graph for position P12, the two-dot chain line is a graph for position P13, and the thin solid line is a graph for position P14.

[0126] 32, the frequency characteristics of the four examples 9 having the gate-shaped protruding conductor 20 appear to be lower than the frequency characteristics of the comparative example in a wide frequency band including the frequency band of the waves transmitted and received by the antenna 4. This shows that the noise of the example 9 is reduced compared to the comparative example. In particular, the frequency characteristics at position P13 appear to be lower than the frequency characteristics of the other three examples 9. The protruding conductor 20 at position P13 of example 9 is provided between the noise source N and the antenna 4. From this result, it can be seen that even in the gate-shaped protruding conductor 20, by being disposed between the noise source N and the antenna 4, the noise reaching the antenna 4 can be effectively reduced.

[0127] [Regarding the protruding conductor 20 having a plate-shaped conductor portion at its tip] Fig. 33 is a diagram showing the frequency characteristics of S21 in Example 10. In Fig. 33, the horizontal axis represents frequency, and the vertical axis represents S21. Here, the positions of the protruding conductors 20 were set to four positions (positions P21, P22, P23, P24) similar to those of the protruding conductors 20 in FIG.

[0128] In FIG. 33, the thick solid line is a graph for the comparative example, the one-dot chain line is a graph for position P21, the broken line is a graph for position P22, the two-dot chain line is a graph for position P23, and the thin solid line is a graph for position P24. As shown in FIG. 33, the frequency characteristics of the four Examples 10 appear to be lower than the frequency characteristics of the comparative example in a wide frequency band including the frequency band of the waves transmitted and received by the antenna 4. In particular, the frequency characteristics at position P23 appear to be lower than the frequency characteristics of the other three Examples 10. The protruding conductor 20 at position P23 of Example 10 is provided between the noise source N and the antenna 4. From the above results, it can be seen that even if the length of the main body 50 is shortened, the noise absorption effect of the plate-like conductor 52 can be maintained, and the protruding conductor 20 can be made smaller.

[0129] [Regarding the spiral-shaped protruding conductor 20] Fig. 34 is a diagram showing the frequency characteristics of S21 in Example 11. In Fig. 34, the horizontal axis represents frequency, and the vertical axis represents S21. Here, the positions of the protruding conductors 20 were set to four positions (positions P21, P22, P23, P24) similar to those of the protruding conductors 20 in FIGS.

[0130] In FIG. 34, the thick solid line is a graph for the comparative example, the one-dot chain line is a graph for position P21, the broken line is a graph for position P22, the two-dot chain line is a graph for position P23, and the thin solid line is a graph for position P24. As shown in FIG. 34, the frequency characteristics of the four examples 11 appear to be lower than the frequency characteristics of the comparative example in a wide frequency band including the frequency band of the waves transmitted and received by the antenna 4. In particular, the frequency characteristics at position P23 appear to be lower than the frequency characteristics of the other three Examples 10. The protruding conductor 20 at position P23 of Example 10 is provided between the noise source N and the antenna 4. From the above results, it can be seen that by making the protruding conductor 20 spiral, the required length of the protruding conductor 20 can be ensured and the noise absorption effect can be maintained, while the protruding height of the protruding conductor 20 can be kept low.

[0131] 〔others〕 It should be noted that the embodiments disclosed herein are to be considered as illustrative in all respects and not restrictive. For example, in the above-described embodiments and examples, the antenna 4 is provided on the edge of the circuit board 3. However, the antenna 4 may be provided around the periphery of the circuit board 3 or may be disposed opposite the circuit board 3.

[0132] In addition, in the above-described embodiments and examples, the protruding conductors are perpendicular to the substrate surface. However, the protruding conductors may protrude obliquely from the substrate surface as long as they protrude from the substrate surface.

[0133] In the above-described embodiments and examples, the first circuit components that are noise sources are exemplified as a crystal oscillator, a USB connector, and a LAN chip. However, the first circuit components also include DDR (Double Data Rate) SDRAMs. Therefore, when DDR SDRAMs are mounted on the board surface 3a, providing a protruding conductor near the DDR SDRAM as in the above-described embodiments can reduce noise reaching the antenna.

[0134] In addition, in the above-described embodiments and examples, the antenna 4 includes an inverted-F antenna. However, the antenna 4 may include other monopole antennas, such as an inverted-L antenna, or a dipole antenna. In addition, in each of the above-described embodiments, the antenna 4 includes the antenna substrate 4a and the antenna pattern 4b. However, the antenna 4 may be configured by a metal plate provided on the substrate surface 3a. In this case, the antenna 4 may include an inverted-F antenna, an inverted-L antenna, or a dipole antenna, depending on the shape of the metal plate. Furthermore, when the antenna 4 is fixed to the housing 6, the antenna 4 may include a dipole antenna (including a modified dipole antenna) provided on the inner surface of the housing 6. Furthermore, the antenna 4 may have an antenna pattern on the substrate surface 3a. In this case, the antenna 4 may include an inverted-F antenna, an inverted-L antenna, or a dipole antenna, since the antenna pattern on the substrate surface 3a has a predetermined shape.

[0135] Furthermore, in each of the above-described embodiments, a single-layer circuit board 3 having a ground conductor portion 3g on the back surface 3b side has been exemplified. However, the circuit board 3 may be configured using a multilayer board having the ground conductor portion 3g in an inner layer. When the circuit board 3 is configured using a multilayer board, the first circuit component and the second circuit component may be mounted on both the board surface 3a and the back surface 3b. The protruding conductor is provided on the surface on which the first circuit component is mounted. Therefore, when the first circuit component is mounted on both the board surface 3a and the back surface 3b, the protruding conductor is provided on both the board surface 3a and the back surface 3b. When the first circuit component is mounted only on the back surface 3b, the protruding conductor is provided on the back surface 3b.

[0136] The scope of the present invention is defined by the claims, not by the meaning described above, and is intended to include meanings equivalent to the claims and all modifications within the scope thereof. [Explanation of symbols]

[0137] 1. Wireless communication device 2. Wireless module (transmitter / receiver) 3 Circuit Board 3a Board surface 3a1 1st point 3a2 2nd point 3b back side 3g Ground conductor 3p board body 3p1 PCB main body surface 3p2 hole 4 Antennas 4a Antenna board 4b Antenna pattern 4b1 Antenna element 4b2 Power supply point 4p 1st end point 4q 2nd end point 4r points 6. Housing 6a Legs 8. Wireless Chip 10 Crystal oscillator (first circuit component) 10p center point 12 Processing circuit chip 13 LAN chip 14 USB connector (first circuit component) 14p center point 16 LAN connector 20 First protruding conductor (protruding conductor) 20a Proximal end 20b Tip 20c 1st end 20d 2nd end 22 Second protruding conductor (protruding conductor) 24 Main body 25 Third protruding conductor (protruding conductor) 26 Protrusion 28 Horizontal section 30 Main body 32 1st protrusion 34 Second protrusion 36 Horizontal section 40 First Conductor 42 Second Conductor 50 Main body 52 Plate-shaped conductor 54 Main body N noise source A1 area A2 area L1 Virtual line (passing line) L2 Virtual Line L3 Virtual Line L4 Virtual Line L5 Virtual Line L6 Virtual Line P1 position P11 position P12 position P13 position P14 position P2 position P21 position P22 position P23 position P24 position P3 position P4 position b dimension c interval h length j Longitudinal dimension k diameter n length r diameter s distance s1 distance s2 distance w distance w1 distance w2 distance x distance

Claims

1. a circuit board having a board surface on which a first circuit component that is a noise source and a second circuit component that is disposed around the first circuit component are provided; an antenna provided on an edge of the circuit board or around the periphery of the circuit board; at least one protruding conductor that is provided on the substrate surface and is grounded and is not fed with power; the protruding conductor is provided at a position closer to the first circuit component than to the second circuit component, The distance between the protruding conductor and the first circuit component is shorter than the distance between the protruding conductor and the antenna. Wireless communication device.

2. The protruding conductor is disposed in a region between the first circuit component and the antenna. The wireless communication device according to claim 1 .

3. the at least one protruding conductor includes two or more protruding conductors; The two or more protruding conductors are provided so as to surround the first circuit component. The wireless communication device according to claim 1 .

4. The protruding conductor is provided on a passing line that is a straight line that passes through the first circuit component and the antenna and minimizes the distance between the first circuit component and the antenna. The wireless communication device according to claim 1 .

5. The protruding conductor is a base end portion connected to the substrate surface and to a ground conductor; and a tip portion that is an electrically open end. The wireless communication device according to claim 1 .

6. The protruding conductor includes a pin-shaped main body portion extending from the base end portion to the tip end portion. The wireless communication device according to claim 5 .

7. The protruding conductor includes a main body portion having a spiral shape extending from the base end portion to the tip end portion along a direction intersecting the substrate surface. The wireless communication device according to claim 5 .

8. The protruding conductor includes a plate-shaped main body portion extending from the base end portion to the tip end portion. The wireless communication device according to claim 5 .

9. The main body portion is a protrusion extending from the base end along a direction intersecting the substrate surface; a horizontally extending portion extending from the tip of the protrusion to the tip portion along the surface direction of the substrate surface; The wireless communication device according to claim 6.

10. The length from the base end to the tip end of the protruding conductor is 0.2 to 0.25 times the wavelength of the radio wave transmitted and received by the antenna. The wireless communication device according to any one of claims 5 to 9.

11. The protruding conductor is a rod-shaped main body portion extending from the base end portion to the tip end portion along a direction intersecting the substrate surface; and a plate-shaped conductor portion provided at an end portion of the main body portion on the tip end side. The wireless communication device according to claim 5 .

12. The protruding conductor is a first end portion connected to a first point on the substrate surface; a second end portion connected to a second point on the substrate surface that is different from the first point; a rod-shaped main body portion connecting the first end portion and the second end portion; The wireless communication device according to claim 1 .

13. The length from the first end to the second end of the protruding conductor is 0.4 to 0.5 times the wavelength of the radio wave transmitted and received by the antenna.

13. The wireless communication device of claim 12.

14. the at least one protruding conductor is plural; the plurality of protruding conductors include a first conductor and a second conductor; The length from the base end to the tip end of the first conductor is different from the length from the base end to the tip end of the second conductor. The wireless communication device according to claim 5 .

15. the antenna is capable of transmitting and receiving a first radio wave having a first wavelength and also capable of transmitting and receiving a second radio wave having a second wavelength different from the first wavelength, a length from the base end to the tip end of the first conductor is 0.2 to 0.25 times the first wavelength, The length from the base end to the tip end of the second conductor is 0.2 to 0.25 times the second wavelength.

15. The wireless communication device of claim 14.

16. a circuit board having a board surface on which a first circuit component that is a noise source and a second circuit component that is disposed around the first circuit component are provided; an antenna provided on an edge of the circuit board or around the periphery of the circuit board; at least one protruding conductor that is provided on the substrate surface and is grounded and is not fed with power; The distance between the protruding conductor and the first circuit component is shorter than the distance between the protruding conductor and the antenna. Wireless communication device.

17. The first circuit component includes any one of a crystal oscillator, a USB connector, and a LAN chip.

17. The wireless communication device of claim 16.

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