JP2006186436A - Dielectric resonator antenna, wiring board and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wideband dielectric resonator antenna in which directivity gain can be increased without employing an array antenna, and to provide a wiring board equipped with the dielectric resonator. <P>SOLUTION: In the dielectric resonator antenna having a high frequency line 4 consisting of a line conductor 2 formed on the upper surface of a dielectric layer 1 and a ground layer 3 formed on the lower surface of the dielectric layer 1 where a slot 6 coupled electromagnetically with the high frequency line 4 is formed in the ground layer 3 perpendicularly to the line conductor 2 in the plan view and a signal transmitting on the line conductor 2 is radiated into the space through the slot 6, a dielectric resonator 7 consisting of a dielectric plate is fixed to the lower surface of the ground layer 3 to cover the slot 6, and a partition conductor 8 is arranged in the dielectric resonator 7 or on the lower surface thereof to overlap the slot 6 in the plan view while being spaced apart from the side face of the dielectric resonator. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to an antenna used for communication and radar using microwaves and millimeter waves, and a dielectric resonator antenna that has a large directivity gain and can be thinned with a single element, a wiring board using the dielectric resonator antenna, and It relates to electronic devices.

  A horn antenna using a waveguide is known as an antenna that efficiently radiates electromagnetic waves such as microwaves and millimeter waves. A horn antenna is an antenna that radiates a high-frequency signal transmitted through a waveguide into space. The inside of the waveguide has the same dielectric constant as that of space (generally, the dielectric constant of air), and its impedance is close to that of space. The electromagnetic field mode of the high-frequency signal transmitted through the waveguide is similar to the electromagnetic field mode of the high-frequency signal transmitted through the space, and the electromagnetic field mode of the high-frequency signal transmitted through the waveguide transmits the space in the space near the horn. Easily change to electromagnetic field mode for high frequency signals. For these reasons, it is known that a horn antenna has low reflection due to impedance and electromagnetic field mode mismatch, and is highly efficient and has a relatively wide bandwidth. It is also known that the directivity gain can be increased by increasing the opening area of the horn.

  On the other hand, circuits generally used for communication and radar using microwaves and millimeter waves are planar circuits using microstrip lines and coplanar lines. In this case, in order to connect the circuit and the horn antenna, a converter for converting the planar circuit into the waveguide is required, and the use of the converter may cause an increase in cost and performance degradation such as reflection. A patch antenna is known as one of antennas that directly radiate electromagnetic waves from a planar circuit into space. In the patch antenna, a planar circuit having a relatively small impedance and a space having a relatively large impedance are matched using the resonance of the patch. In matching by resonance, the impedance of the resonator affects the band. In order to increase the impedance of the patch in order to widen the band, it is necessary to reduce the patch width, and the radiation efficiency decreases. Increasing the patch width to increase the radiation efficiency tends to reduce the patch impedance and narrow the band. In the design of a patch antenna, the first condition is to efficiently radiate a high-frequency signal into the space. Therefore, the band is often narrowed at the expense of the band.

In order to solve this problem, a laminated aperture antenna using a dielectric resonator having a large impedance as a resonator has been proposed. In this laminated aperture antenna, a dielectric resonator is formed inside a dielectric substrate forming a planar circuit, thereby realizing a broadband antenna.
JP 2001-016027 A

  However, since the aperture area of the dielectric resonator of the laminated aperture antenna is generally smaller than the patch area of the patch antenna, the directivity gain when viewed as a single element tends to be small. This is because the effective dielectric constant in the dielectric resonator is approximately the dielectric constant of the dielectric, whereas the effective dielectric constant on the patch is an intermediate dielectric constant between air and dielectric, which is greater than the dielectric constant of the dielectric. This is because it becomes smaller. These are resonators based on half-wave resonance, and the opening area of a dielectric resonator having a larger effective dielectric constant for the same half wavelength is smaller than the patch area of a patch antenna having a smaller effective dielectric constant. . The directivity gain of the aperture antenna has a property of increasing as the aperture area increases. If the loss is ignored, the directivity gain increases twice (increases by 3 dBi) when the aperture area is doubled. It is conceivable to arrange array antenna elements as a means to increase the directivity gain. In that case, however, it is possible to branch the feed line with a small reflection loss, and the length of the feed line to make the phase difference an integral multiple of the wavelength. Adjustment and routing are required, and there is a problem that the design cannot be performed in some cases.

  Accordingly, the present invention has been completed in view of the above-mentioned conventional problems, and an object of the present invention is to provide a dielectric resonator antenna that can increase the directivity gain without being arrayed in a wide-band dielectric resonator antenna. And providing a wiring board including the dielectric resonator.

  The dielectric resonator antenna according to the present invention includes a high-frequency line including a line conductor formed on an upper surface of a dielectric layer and a ground layer formed on a lower surface of the dielectric layer. An antenna for forming a slot to be coupled to each other and radiating a signal transmitted through the high-frequency line to the space through the slot, the dielectric comprising a dielectric plate so as to cover the slot on the lower surface of the ground layer A resonator is attached, and a partition conductor is disposed on the inside or the lower surface of the dielectric resonator so as to overlap the slot when seen in a plan view and spaced apart from the side surface of the dielectric resonator.

  The dielectric resonator antenna according to the present invention includes a high-frequency line including a line conductor formed on an upper surface of a dielectric layer and a ground layer formed on a lower surface of the dielectric layer. An antenna for forming a slot to be coupled to each other and radiating a signal transmitted through the high-frequency line to the space through the slot, the dielectric comprising a dielectric plate so as to cover the slot on the lower surface of the ground layer A resonator is attached, and a cavity or a recess that overlaps with the slot when seen in a plan view is formed inside or on the surface of the dielectric resonator.

  The dielectric resonator antenna of the present invention is preferably characterized in that a conductor layer is formed on a side surface of the dielectric resonator.

  In the dielectric resonator antenna of the present invention, preferably, a plurality of shield conductors are arranged inside the dielectric plate so as to surround the slot in a plan view, and an inner region of the shield conductor group is disposed in the dielectric body. It is characterized by being a resonator.

  The dielectric resonator antenna of the present invention is preferably characterized in that the dielectric resonator has a relative dielectric constant of 3 or more and 10 or less.

  The dielectric resonator antenna of the present invention is preferably characterized in that an upper dielectric layer and an upper ground layer are sequentially laminated on the line conductor.

  In the dielectric resonator antenna of the present invention, preferably, one end of the line conductor is opened, and a distance between a center of a portion intersecting with the slot and one end of the line conductor is determined by a high-frequency signal transmitted through the line conductor. The wavelength is (2n-1) / 4 times (n is a natural number).

  The dielectric resonator antenna of the present invention is preferably characterized in that one end of the line conductor is electrically connected to the ground layer.

  In the dielectric resonator antenna of the present invention, preferably, the distance between the center of the portion where the line conductor intersects the slot and the one end is n / 2 times the wavelength of the high-frequency signal transmitted through the line conductor ( n is a natural number).

  The wiring board of the present invention is characterized in that the dielectric resonator antenna of the present invention is formed on a wiring board having an electronic component mounting portion so that the mounting portion and the line conductor are close to each other.

  The electronic device of the present invention is characterized in that an electronic component is mounted on the wiring board of the present invention, and an electrode of the electronic component and the line conductor are electrically connected.

  The dielectric resonator antenna of the present invention has a dielectric resonator composed of a dielectric plate attached to the lower surface of the ground layer so as to cover the slot, and the slot and the inner surface or lower surface of the dielectric resonator can be seen through in plan view. Since the partition conductors are arranged apart from the side surfaces of the dielectric resonators and overlap, a plurality of resonance phenomena are generated in the dielectric resonators by the partition conductors, so that the opening area of the dielectric resonators can be increased. And an antenna with a large directivity gain can be provided.

  In the dielectric resonator antenna of the present invention, a dielectric resonator composed of a dielectric plate is attached to the lower surface of the ground layer so as to cover the slot, and the inside or the surface of the dielectric resonator is seen through in plan view. Since the cavity or recess that overlaps with the slot is formed, a plurality of resonance phenomena are generated in the dielectric resonator by the cavity or recess, so that the opening area of the dielectric resonator can be increased and the directivity gain can be increased. Can provide a large antenna.

  In the dielectric resonator antenna of the present invention, preferably, since the conductor layer is formed on the side surface of the dielectric resonator, the antenna characteristics are not easily influenced by members around the dielectric resonator, and the dielectric with stable performance is obtained. A body resonator antenna can be provided.

  In the dielectric resonator antenna of the present invention, preferably, a plurality of shield conductors are arranged inside the dielectric plate so as to surround the slot in a plan view, and the inner region of the shield conductor group is a dielectric resonator. Therefore, the dielectric resonator can be configured integrally with the high-frequency line by using the lamination technique, and the dielectric resonator antenna having a stable performance can be provided without the displacement of the junction of the dielectric resonator to the high-frequency line. it can.

  In the dielectric resonator antenna of the present invention, preferably, since the relative permittivity of the dielectric resonator is 3 or more and 10 or less, the ratio of the relative permittivity is 3 or more at the interface where the dielectric resonator is in contact with the space. A part of the electromagnetic wave is reflected to increase, and the function as a resonator can be exhibited. In addition, since the dielectric resonator has a relative dielectric constant of 10 or less, the dielectric resonator does not become too small, and the required directional gain can be obtained, and the dielectric resonator antenna having high efficiency and high directional gain. Can provide.

  In the dielectric resonator antenna of the present invention, preferably, since the upper dielectric layer and the upper ground layer are sequentially laminated on the line conductor, a slight amount of signal from the high frequency line in the direction opposite to the dielectric resonator is reduced. Leakage can be suppressed, and a highly efficient dielectric resonator antenna can be provided.

  In the dielectric resonator antenna of the present invention, preferably, one end of the line conductor is opened, and the distance between the center of the portion where the line conductor intersects the slot and one end of the line conductor is determined by the wavelength of the high-frequency signal transmitted through the line conductor. Therefore, when n is 1, for example, the distance between the open end of the line conductor and the center of the slot is 1/4 times the wavelength of the high-frequency signal. become. The current at the open end is 0, the current of the line conductor is maximized at a position that is 1/4 times the wavelength of the high-frequency signal from the open end, that is, at the center of the slot, and the slot is efficiently excited by the magnetic field generated by the current of the line conductor. As a result, an efficient dielectric resonator antenna can be provided. When n is 2, the distance between the open end and the center of the slot is 3/4 times the wavelength of the high-frequency signal, and the current of the line conductor is maximized at the center of the slot as in the case where n is 1. An efficient dielectric resonator antenna can be provided. Similarly, when n is a natural number of 3 or more, the current of the line conductor is maximized at the center of the slot, and an efficient dielectric resonator antenna can be provided.

  In the dielectric resonator antenna of the present invention, preferably, since one end of the line conductor is electrically connected to the ground layer, a maximum current due to a short circuit flows through the line conductor at the slot edge, and a magnetic field due to the current of the line conductor. Thus, the slot can be excited efficiently, and as a result, an efficient dielectric resonator antenna can be provided.

  In the dielectric resonator antenna of the present invention, preferably, the distance between the center and one end of the portion where the line conductor intersects the slot is n / 2 times the wavelength of the high-frequency signal transmitted through the line conductor (n is a natural number). As a result, a standing wave that repeats the current 0 and the maximum current is generated every time it is separated from the short-circuited end by a quarter of the wavelength of the high-frequency signal. Therefore, the slot can be efficiently excited by the magnetic field generated by this current, and as a result, an efficient dielectric resonator antenna can be provided.

  In the wiring board of the present invention, the dielectric resonator antenna of the present invention is formed on the wiring board having the mounting part of the electronic component so that the mounting part and the line conductor are close to each other. A wiring board having an antenna having a large directional gain, which can increase the opening area of the dielectric resonator because a plurality of resonance phenomena are generated in the dielectric resonator by arranging a partition conductor inside or on the surface. Can be provided.

  An electronic device according to the present invention includes an electronic device including an antenna having a large directivity gain because the electronic component is mounted on the wiring board of the present invention and the electrode of the electronic component and the line conductor are electrically connected. Can be provided.

  The dielectric resonator antenna of the present invention will be described in detail with reference to the drawings. 1A and 1B are schematic views for explaining an example of a dielectric resonator antenna according to the present invention. FIG. 1A is a top view, FIG. 1B is a cross-sectional view along A-AA, and FIG. 1C is a cross-sectional view along B-BB. is there.

  In FIG. 1, 1 is a dielectric layer, 2 is a line conductor, 3 is a ground layer, 4 is a high frequency line, 5 is an open end, 6 is a slot, 7 is a dielectric resonator, 8 is a partition conductor, and H1 is a slot. The magnetic field of the coupled high frequency signal, H2, is the magnetic field of the resonance phenomenon in the dielectric resonator.

  In the example of the dielectric resonator antenna of the present invention, a microstrip is formed from a dielectric layer 1, a line conductor 2 formed on the upper surface of the dielectric layer 1, and a ground layer 3 formed on the lower surface of the dielectric layer 1. A line-type high-frequency line 4 is configured. The front end of the line conductor 2 is an open end 5. A slot 6 is formed in the ground layer 3 facing the open end 5, and the high-frequency line 4 and the slot 6 are coupled in high frequency to generate a magnetic field indicated by H <b> 1. A dielectric resonator 7 made of a dielectric is loaded in the slot 6 so that a high frequency signal coupled to the slot 6 can be efficiently radiated into the space. At this time, since the partition conductor 8 is formed in the dielectric resonator 7, two resonance phenomena such as a magnetic field indicated by H 2 are generated in the dielectric resonator 7 so as to sandwich the partition conductor 8. These two resonance phenomena have the same phase, and the high-frequency signal H1 coupled to the slot 6 can be efficiently radiated to the space. As a result, an efficient dielectric resonator antenna can be provided. Since the dielectric resonator can be made larger than when there is no partition conductor 8 and the resonance phenomenon is one, the opening area as the antenna can be increased, and as a result, the dielectric resonator antenna having a large directivity gain can be obtained. Can be provided. At this time, the distance Lo between the open end 5 and the center of the slot 6 is set to (2n-1) / 4 times the wavelength of the high-frequency signal transmitted through the high-frequency line 4 (n is a natural number). The coupling efficiency can be increased. For example, when n is 1, the distance Lo between the open end 5 of the line conductor 2 and the center of the slot 6 is 1/4 times the wavelength of the high-frequency signal. The high frequency signal is totally reflected at the open end 5 to generate a standing wave on the high frequency line 4. The current of the standing wave is 0 at the open end 5 and becomes maximum at a position away from the open end 5 by a quarter of the wavelength of the high-frequency signal, that is, at the center of the slot 6. Slot 6 can be excited. When n is 2, Lo becomes 3/4 times the wavelength of the high frequency signal. The standing wave current is 0 at the open end 5, and is 0 or 3/4 times away from the open end 5 at a position 2/4 times away from the open end 5, or a slot away from the open end 5. It becomes maximum again at the center of 6 and the slot 6 can be efficiently excited by the magnetic field generated by the current of the line conductor 2. Similarly, when n is 3 or more, the standing wave current is maximized at the center of the slot 6, and the slot 6 can be efficiently excited by the magnetic field generated by the current of the line conductor 2.

  2A and 2B are schematic views for explaining another example of the dielectric resonator antenna of the present invention. FIG. 2A is a top view, FIG. 2B is a C-CC sectional view, and FIG. 2C is a D-DD section. FIG.

  2, the same parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, 9 is a short-circuit conductor, 10 is a short-circuit end, 11 is a recess, and Ls is a short-circuit end length.

  Compared with the example of FIG. 1, the example of the dielectric resonator antenna of the present invention has one end of the line conductor 2 opened to form an open end 5 in the example of FIG. 1 is electrically connected to the ground layer 3 by the short-circuit conductor 9 and the portion where the short-circuit end 10 is formed, and in the example of FIG. 1, the dielectric resonator 7 is divided into two by the partition conductor 8. On the other hand, in this example, the dielectric resonator 7 is a portion that is divided into two by the recess 11. The short-circuit end 10 of the high-frequency line 4 adjusts the distance between the short-circuit end 10 and the center of the slot 6 to couple the high-frequency signal transmitted through the high-frequency line 4 to the slot 6 in a high frequency manner as in the case of the open end 5. Can do. Further, the dielectric resonator 7 can be divided by the partition conductor 8 as in the example of FIG. 1, but can also be divided by the concave portion 11 having a relatively low dielectric constant. Therefore, as in the example of FIG. 1, a dielectric resonator antenna with high efficiency and large directivity gain can be provided. In this example, when the line conductor 2 crosses immediately above the slot 6 and is short-circuited to the edge of the slot 6, the current becomes maximum at the short-circuited end 10, and the maximum magnetic field due to this maximum current is generated in the slot 6. It can be combined efficiently. When the distance Ls between the short-circuited end 10 and the center of the slot 6 is n / 2 times the wavelength of the high-frequency signal (n is a natural number), Ls is 1/2 times the wavelength of the high-frequency signal (n = 1), 1 Double (n = 2). When the tip of the high frequency line is short-circuited, the high-frequency signal is totally reflected at the short-circuited end, and a standing wave is generated in the high-frequency line. This standing wave current is the maximum at the short-circuited end, and the current 0 and the maximum current are repeated each time the short-circuited end is separated by 1/4 of the wavelength of the high-frequency signal. Therefore, if the slot is formed at a position away from the short-circuited end by an integral multiple of 2/4 times the wavelength of the high-frequency signal, the high-frequency line and the slot can be efficiently coupled, resulting in a dielectric resonator having good radiation efficiency. An antenna can be provided. Further, if the dielectric resonators 7 are divided by the recesses 11 to increase the size of each dielectric resonator, the entire dielectric resonator 7 becomes larger, the opening area of the antenna becomes larger, and as a result, the directivity gain is increased. A large dielectric resonator antenna can be provided.

  3A and 3B are schematic views for explaining an example of the wiring board of the present invention, wherein FIG. 3A is a top view and FIG. 3B is an E-EE sectional view.

  In FIG. 3, the same parts as in FIG. 1 are denoted by the same symbols as in FIG. 1, 12 is a side conductor group, 13 is an upper dielectric layer, 14 is an upper conductor layer, 15 is a connection conductor, 16 is a high-frequency element, 17 is wire bonding, and 18 is a lid. In this example of the present invention, the ground layer 3 is formed inside the dielectric layer 1, and the side surface conductor group 12 is formed so as to surround the slot 6 below the ground layer 3 to form the dielectric resonator 7. ing. An upper dielectric layer 13 is formed on the dielectric layer 1, and an upper conductor layer 14 is formed on the upper dielectric layer 13. The upper conductor layer 14 is electrically connected to the ground layer 3 by a connection conductor 15. One end of the line conductor 2 is an open end 5 for high frequency coupling with the slot 6, and the other end is connected to the high frequency element 16 by wire bonding 17. The high frequency element 17 is hermetically sealed by a lid 18 joined to the upper conductor layer 14. With such a configuration, the dielectric resonator 7 can be formed integrally with a part of the dielectric layer 1, and the production of the dielectric resonator antenna can be facilitated. Since the high frequency element 16 can be mounted on the surface of the layer 1 opposite to the antenna radiation surface, the device can be downsized. Further, in this example, the upper dielectric layer 13 is disposed on the upper side of the dielectric layer 1 and the upper conductor layer 14 is disposed on the upper surface of the upper dielectric layer 13, so that leakage of electromagnetic waves from the slot 6 to the upper side is suppressed. In addition, a dielectric resonator antenna with good radiation efficiency can be provided.

  It should be noted that the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

It is the schematic for demonstrating an example of the dielectric resonator antenna of this invention, (a) is a top view, (b) is AAAA sectional drawing, (c) is B-BB sectional drawing. It is the schematic for demonstrating another example of the dielectric resonator antenna of this invention, (a) is a top view, (b) is C-CC sectional drawing, (c) is D-DD sectional drawing. It is the schematic for demonstrating an example of the wiring board of this invention, (a) is a top view, (b) is E-EE sectional drawing.

Explanation of symbols

1: Dielectric layer 2: Line conductor 3: Ground layer 4: High frequency line 5: Open end 6: Slot 7: Dielectric resonator 8: Partition conductor 9: Short-circuit conductor
10: Short circuit end
11: Recess
12: Side conductor group
13: Upper dielectric layer
14: Upper conductor layer
15: Connection conductor
16: High frequency element
17: Wire bonding
18: Lid H1: Magnetic field H2 in slot: Magnetic field Lo in dielectric resonator Lo: Distance from open end to slot center Ls: Distance from short-circuited end to slot center

Claims (11)

A high-frequency line composed of a line conductor formed on the upper surface of the dielectric layer and a ground layer formed on the lower surface of the dielectric layer, and is orthogonal to the line conductor as seen through the ground layer in a plan view and the high-frequency line. An antenna that forms a slot for electromagnetic coupling and radiates a signal transmitted through the high-frequency line to the space through the slot, and is a dielectric plate made of a dielectric plate so as to cover the slot on the lower surface of the ground layer. A dielectric resonator is mounted, and a partition conductor is disposed on the inside or the bottom surface of the dielectric resonator so as to overlap the slot when seen in a plan view and spaced apart from the side surface of the dielectric resonator. Body resonator antenna. Forming a slot electromagnetically coupled to the high-frequency line in the ground layer of a high-frequency line comprising a line conductor formed on the upper surface of the dielectric layer and a ground layer formed on the lower surface of the dielectric layer; An antenna that radiates a signal transmitted through a high-frequency line to the space through the slot, and a dielectric resonator made of a dielectric plate is attached to a lower surface of the ground layer so as to cover the slot, and the dielectric A dielectric resonator antenna characterized in that a cavity or a recess that overlaps with the slot as seen through a plane is formed inside or on the surface of the resonator. 3. The dielectric resonator antenna according to claim 1, wherein a conductor layer is formed on a side surface of the dielectric resonator. A plurality of shield conductors are arranged inside the dielectric plate so as to surround the slot in a plan view, and an inner region of the shield conductor group is used as the dielectric resonator. The dielectric resonator antenna according to claim 3. 5. The dielectric resonator antenna according to claim 1, wherein a relative dielectric constant of the dielectric resonator is 3 or more and 10 or less. 6. The dielectric resonator antenna according to claim 1, wherein an upper dielectric layer and an upper ground layer are sequentially laminated on the line conductor. One end of the line conductor is opened, and the distance between the center of the part intersecting the slot and one end of the line conductor is (2n-1) / 4 times the wavelength of the high-frequency signal transmitted through the line conductor (n is 7. The dielectric resonator antenna according to claim 1, wherein the dielectric resonator antenna is a natural number. The dielectric resonator antenna according to claim 1, wherein one end of the line conductor is electrically connected to the ground layer. The distance between the center of the portion where the line conductor intersects with the slot and the one end is set to n / 2 times the wavelength of the high-frequency signal transmitted through the line conductor (n is a natural number). 9. The dielectric resonator antenna according to 8. A dielectric resonator antenna according to any one of claims 1 to 9 is formed on a wiring board having an electronic component mounting portion so that the mounting portion and the line conductor are close to each other. Wiring board to be used. An electronic device comprising an electronic component mounted on the wiring board according to claim 10 and an electrode of the electronic component and the line conductor electrically connected.

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