JP4479606B2 - Antenna device - Google Patents

Description

  The present invention relates to an antenna device, and more particularly to a small and high-performance antenna device with a built-in transmission / reception circuit.

  In a conventional wireless transceiver, a chip antenna is mounted on a printed circuit board, and a transmitter / receiver circuit is configured by mounting a semiconductor IC chip and other chip components. As the chip antenna, a patch antenna is preferably used in which a radiation electrode made of a rectangular conductor pattern is formed on the top surface of a dielectric substrate, and a ground electrode is formed on almost the entire bottom surface (see Patent Document 1).

  In such a conventional wireless transceiver, since it is necessary to mount many chip parts on the printed circuit board including the patch antenna, there is a limit in reducing the size, thickness and weight of the wireless transceiver, There is a problem that the manufacturing process becomes very complicated. Therefore, it is desired that the mounted chip parts also be provided as small and highly functional composite parts that contribute to miniaturization of the radio transceiver.

  Under such circumstances, recently, an antenna integrated high-frequency circuit module has been considered (see Patent Document 1). In this module, a radiation electrode is formed on the surface of the dielectric substrate, a penetration portion is formed in a portion of the dielectric substrate that avoids a region where the radiation electrode is formed, and a circuit board that closes the surface side opening of the penetration portion is provided. A high-frequency circuit is formed on a circuit board.

As another conventional antenna device, a dielectric substrate for forming a radiation electrode and a mounting circuit substrate for forming an electronic circuit are separately formed, and a space is formed between the dielectric substrate and the mounting circuit substrate. As described above, there is known a method of assembling these substrates in layers with a support member interposed therebetween (see Patent Document 2).
JP 2003-347834 A JP 2001-308620 A

  However, the above-described conventional antenna-integrated high-frequency circuit module has a problem that the mounting area of the module on the printed circuit board increases. In another conventional antenna device, since the support member is interposed so as to form a space between the dielectric substrate and the mounting circuit substrate and these substrates are assembled in layers, the thickness of the antenna device is reduced. There is a problem that the demand for miniaturization cannot be met.

  Accordingly, an object of the present invention is to provide a small and high-performance antenna device with a built-in transmission / reception circuit.

  The object of the present invention includes a dielectric substrate, a radiation electrode formed on the surface of the dielectric substrate, a first ground electrode embedded in the dielectric substrate, and a transmission / reception circuit. The ground electrode faces the radiation electrode via a dielectric layer constituting the dielectric substrate, and the transmission / reception circuit includes the radiation electrode and the first ground in the dielectric substrate. This is achieved by the antenna device arranged in a region different from the region sandwiched between the electrodes. According to this, the patch antenna and the high frequency circuit can be integrated, and in particular, since only the dielectric layer is interposed between the radiation electrode and the ground electrode of the patch antenna, the antenna characteristics are excellent. A transmission / reception circuit integrated antenna can be realized.

  In the present invention, the dielectric substrate has a laminated structure, the first ground electrode is provided on the inner conductor layer of the dielectric substrate, and the transmission / reception circuit is provided in the same layer as the first ground electrode. It is preferable that a wiring pattern to be configured is provided, and an electronic component configuring the transmission / reception circuit is mounted on the wiring pattern. According to this, since the first ground electrode and the pattern are provided on the same plane, both of them can be formed by a single pattern etching, and the manufacturing process can be made more efficient.

  In the present invention, it is preferable that a bottom terminal provided on the bottom surface of the dielectric substrate is further provided, and the first ground electrode is connected to the bottom terminal through a via hole. According to this, when the antenna device is mounted on the printed board, the first ground electrode and the ground line on the printed board can be reliably connected.

  In the present invention, it is preferable to further include a second ground electrode provided above the transmission / reception circuit and covering at least a part of the transmission / reception circuit. Specifically, the electronic component includes a semiconductor IC chip, and coupling with the electromagnetic field of the antenna is such that the second ground electrode is selectively above the periphery of the semiconductor IC chip constituting the transmission / reception circuit. It is preferable to cover. According to this, unnecessary radiation from the transmission / reception circuit can be shielded, and deterioration of the antenna characteristics can be prevented.

  In the present invention, the dielectric substrate has a laminated structure, the first ground electrode is provided on an inner conductor layer of the dielectric substrate, and the transmission / reception is performed on a layer different from the first ground electrode. It is also preferred that a circuit is provided. According to this, the first ground electrode functions as a ground plane of the patch antenna, can shield unwanted radiation from the transmission / reception circuit, and can prevent deterioration of the antenna characteristics. Moreover, since the size of the dielectric substrate in the planar direction can be reduced, the antenna device can be downsized.

  In the present invention, the region where the radiation electrode is formed and the region where the transmission / reception circuit is provided are separated by a slit in the dielectric substrate formed in a direction substantially perpendicular to the surface of the dielectric substrate. It is preferable that According to this, even when the antenna and the transmission / reception circuit interfere with each other and the antenna characteristics are affected, such interference can be prevented.

  The present invention further includes a power supply electrode provided on the same plane in proximity to one side of the radiation electrode, and a via-hole electrode provided in the dielectric substrate and connecting the power supply electrode and the transmission / reception circuit. It is preferable. According to this, a radiation electrode and a transmission / reception circuit can be electrically connected.

  According to the present invention, the patch antenna and the high-frequency circuit can be integrated, and in particular, there is no high-frequency circuit between the radiation electrode and the ground electrode of the patch antenna, and only the dielectric layer is interposed. Therefore, it is possible to realize a small and high performance transmitting / receiving circuit integrated antenna device without affecting the antenna characteristics. Further, by forming the wiring pattern of the transmission / reception circuit in the same layer as the ground electrode constituting a part of the patch antenna, it is possible to rationalize the process by downsizing and the reduction of the lamination process. When such a patch antenna is used for a wireless transceiver, it is possible to contribute to miniaturization of the wireless transceiver.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing a configuration of an antenna device according to a first preferred embodiment of the present invention, and FIG. 2 is a top view thereof.

  As shown in FIGS. 1 and 2, the antenna device 100 includes a substantially block-shaped dielectric substrate 101 containing an RF transceiver circuit, a radiation electrode 102 of a patch antenna formed on the upper surface of the dielectric substrate 101, A feeding electrode 103 provided at a position close to one side of the radiation electrode 102 and a side terminal 104 provided on a side surface of the dielectric substrate 101 are provided.

  The dielectric substrate 101 provides a surface on which the radiation electrode 102 is formed, and the material thereof is not particularly limited. For example, LTCC (low temperature fired ceramic), epoxy thermosetting resin, flexible A good organic film having good high-frequency characteristics can be used. The radiation electrode 102 is formed of a substantially square conductor pattern, and the length L1 of one side is set to approximately λ / 2 with respect to the use wavelength λ. The feed electrode 103 is a transmission line having an impedance of approximately 50Ω with respect to the ground plane, and is disposed so as to be electromagnetically coupled to the radiation electrode 102.

  3 is a side sectional view of the antenna device along the line AA in FIG. 2, FIG. 4 is a side sectional view of the antenna device along the line BB in FIG. 2, and FIG. It is a plane sectional view along line CC.

  As shown in FIGS. 3 and 4, the dielectric substrate 101 has a laminated structure, and in the present embodiment, two layers in which a first dielectric layer 101a and a second dielectric layer 101b are laminated. An electrode layer (internal conductor layer) is provided between these layers. A bottom terminal 105 is provided on the bottom surface of the dielectric substrate 101. As shown in FIG. 5, the planar region of the inner conductor layer of the dielectric substrate 101 is roughly divided into a ground surface formation region S1 and a circuit formation region S2, and the first ground electrode 106 is formed in the ground surface formation region S1. The wiring pattern 107 for the RF transceiver circuit is provided in the circuit formation region S2. These conductor patterns can be simultaneously formed, for example, by pattern etching of a copper foil attached to the surface of the dielectric sheet.

  The first ground electrode 106 is provided below the radiation electrode 102 as a ground surface of the patch antenna, and has an area that covers at least the entire projection surface of the radiation electrode 102. The radiation electrode 102 and the first ground electrode 106 face each other directly only through the dielectric layer 101b constituting the dielectric substrate 101. The first ground electrode 106 is connected to the bottom terminal 105 through a number of via hole electrodes 109. A part of the first ground electrode 106 is drawn into the circuit formation region S2 and used as a ground line of the RF transmission / reception circuit.

  On the wiring pattern 107, electronic components 108 such as a semiconductor IC chip 108a and a chip capacitor 108b are mounted by face bonding, and these constitute an RF transmission / reception circuit. In FIG. 5, the semiconductor IC chip 108 a and the chip capacitor 108 b are mounted at positions indicated by broken lines on the wiring pattern 107. Although not particularly limited, in the present embodiment, these electronic components are mounted on the upper surface side of the wiring pattern.

  The feed electrode 103 is connected to the wiring pattern 107 of the RF transmission / reception circuit through the via-hole electrode 110. A part of the wiring pattern 107 is connected to the side terminal 104, and the other part is connected to the bottom terminal 105 via the via-hole electrode 111. I / O is performed.

  As described above, according to the antenna device 100 of the present embodiment, the wiring pattern 107 of the RF transmission / reception circuit is provided in the same layer as the first ground electrode 106 that is the ground plane of the radiation electrode 102, and RF transmission / reception is performed. Since only one internal conductor layer is necessary for incorporating a circuit, it is not necessary to have a laminated structure in which many layers are stacked. In addition, since the first ground electrode and the conductor pattern are provided in the same layer, the first ground electrode and the conductor pattern are removed by, for example, pattern etching of a copper foil attached to the surface of the dielectric sheet. They can be formed simultaneously. Therefore, the manufacturing process can be simplified, the manufacturing cost can be reduced, and the manufacturing efficiency can be improved. Further, the first ground electrode 106 faces the radiation electrode via the dielectric layer 101 b constituting the dielectric substrate 101, and the transmission / reception circuit is connected to the radiation electrode 102 and the second electrode in the dielectric substrate 101. Since it is arranged in a region different from the region sandwiched between the single ground electrodes 106, it is possible to sufficiently reduce the deterioration of the antenna characteristics due to the built-in transmission / reception circuit.

  In the first embodiment described above, for example, when the leakage of the electromagnetic field from the periphery of the mounting region of the semiconductor IC chip 108a is large and the antenna characteristics are adversely affected, the following configuration can be adopted.

  FIG. 6 is a schematic side cross-sectional view showing the configuration of the antenna device according to the second preferred embodiment of the present invention, and FIG. 7 is a cross-sectional plan view taken along the line DD in FIG. In addition, the same code | symbol is attached | subjected to the component same as 1st Embodiment, and detailed description is abbreviate | omitted.

  As shown in FIGS. 6 and 7, the antenna device 200 is characterized in that a second ground electrode 112 covering the upper side of the semiconductor IC chip 108 a mounted on the wiring pattern 107 is provided. In FIG. 7, the second ground electrode 112 is provided at a position indicated by a broken line. The second ground electrode 112 is connected to the first ground electrode 106 via the via hole electrode 113. Due to such a configuration, the antenna device 200 of the present embodiment has a three-layer structure including a first dielectric layer, a second dielectric layer, and a third dielectric layer, and is formed between these layers. Although the electrode layer (inner conductor layer) is two layers, unnecessary radiation from around the mounting area of the semiconductor IC chip can be shielded, and deterioration of antenna characteristics can be prevented. Although not shown, when an inductor (chip or pattern) is present inside the antenna device 200, a semiconductor IC chip is used to prevent coupling between the magnetic field generated around the inductor and the electromagnetic field of the antenna. Similarly to the case of 108a, the upper portion of the inductor may be selectively covered with the second ground electrode 112.

  In the present embodiment, the second ground electrode is formed only above the semiconductor IC chip 108a. However, as shown in FIG. 8, for example, a wide ground pattern that covers the entire RF transceiver circuit is formed. The second ground electrode 114 may be formed.

  9 is a top view of the antenna device according to the third preferred embodiment of the present invention, FIG. 10 is a side sectional view of the antenna device along the line EE of FIG. 9, and FIG. 11 is F of FIG. It is a plane sectional view of the antenna device along the -F line.

  As shown in FIGS. 9 to 11, the antenna device 500 is characterized in that a wiring pattern 107 is provided by allocating a region (S1) in which the first ground electrode 106 is to be formed to the circuit forming region S2. The dielectric substrate 101 of the antenna device 500 has a three-layer structure in which a first dielectric layer 101a, a second dielectric layer 101b, and a third dielectric layer 101c are stacked, and an electrode is interposed between these layers. A layer (inner conductor layer) is provided. A ground electrode 115 is provided on almost the entire surface of the upper internal conductor layer, and transmission / reception composed of a microstrip line or a lumped constant element having the ground electrode 115 as the ground is formed on almost the entire surface of the lower internal conductor layer. A circuit wiring pattern 107 is provided. A chip component such as an IC chip is mounted below the wiring pattern 107. Further, as shown in the figure, the power supply electrode 103 is connected to the wiring pattern 107 via the side surface terminal 104 instead of the via hole electrode. As described above, according to the present embodiment, the size of the dielectric substrate 101 can be reduced without changing the antenna area, so that the antenna device can be downsized.

  Next, a fourth preferred embodiment of the present invention will be described in detail.

  FIG. 12 is a schematic plan view showing the configuration of the antenna device according to the fourth preferred embodiment of the present invention, and FIG. 13 is a side sectional view taken along the line GG of FIG. In addition, the same code | symbol is attached | subjected to the component same as 1st Embodiment, and detailed description is abbreviate | omitted.

  As shown in FIGS. 12 and 13, the antenna device 600 is characterized in that the radiation electrode 102 and the RF transmitting / receiving circuit are formed in the dielectric substrate 101 in a direction substantially perpendicular to the substrate surface of the dielectric substrate 101. The slit 117 is electromagnetically isolated by the slit 117. The slit 117 is preferably in a hollow state. The slit 117 may penetrate to the bottom surface of the dielectric substrate. As described above, according to the present embodiment, since the slit 117 is provided in the dielectric substrate 101, even when the patch antenna and the RF transceiver circuit interfere with each other and the antenna characteristics are affected. , Such interference can be prevented.

  The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention, and these are also included in the scope of the present invention. Needless to say.

  For example, in each of the above embodiments, the case where the chip component 108 such as a semiconductor IC chip or a chip capacitor is mounted on the upper surface side of the wiring pattern 107 formed in the circuit formation region S2 has been described. The invention is not limited to this. For example, as shown in FIG. 14, the chip capacitor 108b may be mounted from the lower surface side (bottom surface side) of the wiring pattern 107 by face bonding. Although not shown, the semiconductor IC chip may be mounted by face bonding from the lower surface side (bottom surface side) of the wiring pattern. That is, in the present invention, the case where the electronic component is mounted on the wiring pattern means both the case where it is mounted on the front surface of the wiring and the case where it is mounted on the back surface.

  In each of the embodiments described above, the radiation electrode is formed on the upper surface of the dielectric substrate. However, the present invention is not limited to this, and is approximately 1/2 formed on the upper surface or the inner layer of the dielectric. The present invention can also be applied to the case of forming a wavelength linear antenna, a slot antenna, or the like.

FIG. 1 is a perspective view showing a configuration of an antenna device 100 according to a first preferred embodiment of the present invention. FIG. 2 is a top view of the antenna device 100 shown in FIG. FIG. 3 is a side sectional view of the antenna device 100 taken along line AA in FIG. FIG. 4 is a side sectional view of the antenna device 100 taken along line BB in FIG. FIG. 5 is a plan sectional view of the antenna device 100 taken along the line CC of FIG. FIG. 6 is a schematic side sectional view showing the configuration of the antenna device 200 according to the second preferred embodiment of the present invention. FIG. 7 is a plan cross-sectional view of the antenna device 200 taken along the line DD of FIG. FIG. 8 is a schematic plan sectional view showing a modification of the antenna device 200. FIG. 9 is a top view of an antenna device 500 according to a third preferred embodiment of the present invention. FIG. 10 is a schematic cross-sectional side view of the antenna device 500 taken along line EE in FIG. FIG. 11 is a schematic plan sectional view of the antenna device 500 taken along line FF in FIG. FIG. 12 is a schematic plan view showing the configuration of the antenna device 600 according to the fourth preferred embodiment of the present invention. 13 is a schematic cross-sectional side view of the antenna device along the line GG in FIG. FIG. 14 is a schematic side sectional view showing a modification of the embodiment.

Explanation of symbols

100 Antenna Device 101 Dielectric Substrate 101a First Dielectric Layer 101b Second Dielectric Layer 101c Third Dielectric Layer 102 Radiation Electrode 103 Feed Electrode 104 Side Terminal 105 Bottom Terminal 106 Ground Electrode 107 Wiring Pattern 108 Chip Component ( Electronic components)
108a Semiconductor IC chip 108b Chip capacitor 109 Via hole electrode 110 Via hole electrode 111 Via hole electrode 112 Ground electrode 113 Via hole electrode 114 Ground electrode 115 Ground electrode 117 Slit 200 Antenna device 300 Antenna device 400 Antenna device 500 Antenna device 600 Antenna device S1 Ground plane formation region S2 Circuit formation area

Claims (8)

A dielectric substrate; a radiation electrode formed on the surface of the dielectric substrate; a first ground electrode and a transmission / reception circuit embedded in the dielectric substrate; and a position directly below the first ground electrode. A bottom terminal provided on a bottom surface of the dielectric substrate; and a first via-hole electrode connecting the first ground electrode and the bottom terminal , wherein the first ground electrode includes the dielectric substrate. The transmission / reception circuit faces the radiation electrode through a constituting dielectric layer, and the transmission / reception circuit is a region different from a region sandwiched between the radiation electrode and the first ground electrode in the dielectric substrate. An antenna device, wherein   The dielectric substrate has a laminated structure, the first conductor electrode is provided on the inner conductor layer of the dielectric substrate, and the wiring pattern that configures the transmission / reception circuit on the same layer as the first ground electrode The antenna device according to claim 1, wherein an electronic component constituting the transmission / reception circuit is mounted on the wiring pattern. 3. The antenna according to claim 2, comprising a plurality of the first via-hole electrodes, wherein the plurality of first via-hole electrodes are two-dimensionally arranged at a predetermined interval in a planar direction of the dielectric substrate. apparatus. A second ground electrode provided above the transmitting / receiving circuit and covering at least a part of the transmitting / receiving circuit , wherein the second ground electrode is a layer between the radiation electrode and the first ground electrode; the antenna device according to claim 2 or 3, characterized in that provided in the.   5. The antenna according to claim 4, wherein the electronic component includes a semiconductor IC chip, and the second ground electrode selectively covers the periphery of the semiconductor IC chip constituting the transmission / reception circuit. apparatus.   The region directly under the first ground electrode and sandwiched between the first ground electrode and the bottom terminal is a region where there is no electronic component and only the first via hole electrode. The antenna device according to claim 1, wherein:   The region where the radiation electrode is formed and the region where the transmission / reception circuit is provided are separated by a slit in the dielectric substrate formed in a direction substantially perpendicular to the substrate surface of the dielectric substrate. The antenna device according to any one of claims 1 to 6, wherein: A feed electrode provided on the same plane in the vicinity of one side of the radiation electrode; and a second via hole electrode provided in the dielectric substrate and connecting the feed electrode and the transmission / reception circuit. The antenna apparatus according to claim 1, wherein the antenna apparatus is characterized.

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