JP2001094336A - Patch antenna incorporating filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a patch antenna incorporating a filter by facilitating the miniaturization of the patch antenna to which the filter is added and preventing the deterioration of a characteristic such as the narrowing of a band and the drop of radiation efficiency at the time of miniaturization. SOLUTION: In an incorporated patch antenna, a substrate constituted of a dielectric material, a radiation conductor installed on one face of the substrate, aground conductor installed on a face facing one face, a feeding through hole feeding power to the radiation conductor and a dielectric filter which has a GND face on a face parallel to the radiation conductor and is installed in the inner part of the substrate are arranged. The feeding through hole and the dielectric filter are electrically connected in the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to mobile communication, LA
N (Local Area Network) and ITS (Intelligent
Transport System), ETC (Electronic Toll Collec)
and a patch antenna with a built-in filter for use in an application system.

[0002]

FIG. 9 shows a conventional patch antenna PA10.
FIG. FIG. 10 is a sectional view showing a conventional patch antenna PA10.

A conventional patch antenna PA10 is an antenna disclosed in Japanese Patent Application Laid-Open No. 10-145133 or the like, and has a radiation conductor 12 and a ground conductor 1 on a surface of a base 11.
The radiation conductor 12 is connected to the mounting substrate 21 by the power supply through hole 15, and the radiation conductor 12 is connected to the ground conductor 13.
Are connected to a ground pattern 22 on a mounting board 21.

[0004] The base 11 is made of a dielectric such as ceramic or resin. The resonance frequency and the bandwidth
1 is determined by the dielectric constant and thickness of the radiating conductor 12 and the shape and size of the radiating conductor 12. Therefore, when a patch antenna is to be manufactured with a general structure, the shape of the patch antenna PA10 is automatically adjusted when the antenna specifications are determined. Is decided.

[0005]

In order to reduce the size of the above-described conventional example, processing such as bending, cutting, and providing a short-circuit pin for the radiation conductor 12 is performed.

Although there is an advantage that the patch antenna PA10 can be installed on the ground pattern 22, the patch antenna PA10 resonates with the inductance and capacitance determined by the size and shape of the pattern of the radiation conductor 12. Therefore, when trying to resonate with a signal of a predetermined frequency, there is a problem that the shape of the patch antenna PA10 becomes large.

The conventional patch antenna PA10 has a large shape as described above, so that the patch antenna PA1
There is a problem that it is difficult to reduce the size of the O. In addition, in order to reduce the size, it is conceivable to bend, cut, or insert a short-circuit pin in the electrode. However, in this case, deterioration of characteristics such as narrowing of a band or lowering of radiation efficiency is considered. There is a problem that occurs.

[0008] The present invention provides a patch antenna with a built-in filter, in which the size of a patch antenna to which a filter is added can be easily reduced, and characteristics such as narrowing of the band and lowering of radiation efficiency do not occur when the size is reduced. The purpose is to do so.

[0009]

SUMMARY OF THE INVENTION The present invention provides a base made of a dielectric material, a radiating conductor provided on one surface of the base, and a radiating conductor provided on a surface facing the one surface. Grounding conductor, a power supply through-hole for supplying power to the radiation conductor, and a ground plane parallel to the radiation conductor.
A built-in patch antenna having a surface and a dielectric filter provided inside the base, wherein the feed through hole and the dielectric filter are electrically connected inside the base. .

Further, the present invention provides a base made of a dielectric material, a radiation conductor provided on one surface of the base, and a ground conductor provided on a surface facing the one surface. And a power supply through-hole for supplying power to the radiation conductor, a recess provided in a part of the ground conductor in the base, and provided inside the recess,
A built-in filter having a chip-type dielectric filter provided in parallel with the radiation conductor, wherein the power supply through-hole and the dielectric filter are electrically connected inside or on the surface of the base; It is a patch antenna.

[0011]

FIG. 1 is a perspective view showing a patch antenna PA1 with a built-in filter according to a first embodiment of the present invention.

FIG. 2 shows a patch antenna PA with a built-in filter.
1 is a sectional view of FIG.

The patch antenna PA1 with a built-in filter includes a base 11, a radiation conductor 12, a ground conductor 13, a power supply terminal 14, a power supply through hole 15, a capacitor electrode pattern 16, and a built-in dielectric filter 30. Have.

The base 11 is made of a dielectric material (the material need not be limited to a material having a high dielectric constant) and has an insulating property. The radiation conductor 12 is provided on one surface of the base 11, The ground conductor 13 is provided on a surface facing the one surface, and the power supply through hole 15 supplies power to the radiation conductor 12. The dielectric filter 30
Is a triplate type dielectric filter provided with a GND plane on a plane parallel to the radiation conductor 12 and provided inside the base 11.

Further, the power supply through hole 15 and the dielectric filter 30 are electrically connected inside the base 11. That is, the capacitor electrode pattern 16 capacitively couples the power supply through hole 15 and the dielectric filter 30.

Here, a capacitor 41 indicated by a broken line is a coupling capacitance between the radiation conductor 12 and the GND electrode 18.

The patch antenna PA1 with a built-in filter
Is mounted on the printed circuit board 21, and at this time, most of the portion on which the patch antenna with built-in filter PA <b> 1 is mounted is the ground pattern 22. By doing so, the original characteristics of the patch antenna can be secured. In other words, the patch antenna originally has a wide G
It is configured on the ND plane.

In the above embodiments, the dielectric material used is ceramic (cordrite, forsterite, alumina, glass ceramic, titanium oxide ceramic, or a mixture thereof), resin (polytetrafluoroethylene). , Polyimide, bismaleimide,
Triazine, liquid crystal polymer, etc.), a composite material of a ceramic and a resin, and the like, which have insulating properties. The dielectric constant, the mixing ratio of the composite material, and the like are appropriately selected.

The conductor in the above embodiment is gold,
Silver, copper, palladium and the like. When these materials are selected, a material that satisfies the minimum required characteristics for securing the antenna characteristics is selected. Factors that are particularly effective for antenna characteristics are
The tan δ of the elementary body and the dielectric constant of the elementary body.

The base 11 is made of a ceramic substrate formed by a sheet method, a printing method, a molding method, or the like.
It is a resin substrate or a substrate made of a composite material of ceramic and resin, and constitutes the radiation conductor 12, the ground conductor 13, the internal GND electrode 18, the capacitor electrode pattern 16, and the dielectric filter 30 on or in the surface of the substrate. The electrode pattern is formed by a technique such as printing, sputtering, or etching.

When the power supply through hole 15 is provided in the green sheet, a hole is formed in the green sheet by a drill, a laser or the like, and the inside of the opened hole is
An electrode is formed by filling or plating. In this case, if the structure is a multilayer structure, the above-described processing may be performed for each layer.

In the above-mentioned patch antenna PA1 with a built-in filter, since the filter is incorporated in the antenna, the size of the patch antenna to which the filter is added can be reduced, and the size can be easily reduced. This does not cause deterioration of characteristics such as narrowing of the band and lowering of radiation efficiency.

The patch antenna PA1 with a built-in filter
, The power supply through hole 15 and the dielectric filter 3
0 may be directly coupled (directly connected) without using a capacitor.

FIG. 3 is a sectional view showing a patch antenna PA2 with a built-in filter according to a second embodiment of the present invention.

The patch antenna with built-in filter PA2 is mainly different from the patch antenna with built-in filter PA1 in that the filter 31 is provided in the concave portion 11c of the base body 11.

That is, the patch antenna P with a built-in filter
A2 is a base 11, a radiation conductor 12, and a ground conductor 13
Power supply terminal 14, power supply through hole 15, internal electrode pattern 16 a, recess 11 c, internal conductor 17
, An external connection conductor 19, and a chip-type dielectric filter 31.

The recess 11 c is provided in a part of the base 11 on the side of the ground conductor 13, and the chip type dielectric filter 3
1 is provided inside the concave portion 11c and is provided in parallel with the radiation conductor 12. Most of the bottom surface of the concave portion 11c is a GND electrode, and the power supply through hole 15
And the dielectric filter 31 are electrically connected inside the base 11. That is, the power supply through hole 15 and the chip-type dielectric filter 31 are connected to the internal electrode pattern 16.
a is bonded.

In the patch antenna with built-in filter PA2, the characteristics of the antenna and the filter that constitute it can be individually selected, so that the process yield of the patch antenna with built-in filter PA2 can be increased. Further, when designing the patch antenna PA2 with a built-in filter, the antenna and the filter can be adjusted as individual components, so that the adjustment time can be reduced.

The patch antenna PA2 with a built-in filter
Is mounted on the printed circuit board 21 and used.
Most of the part where the patch antenna PA2 with a built-in filter is mounted is the ground pattern 22.

In the above embodiment, the base material, the electrode material, the method of forming the substrate, the method of forming the terminals, and the like used are the same as those in the patch antenna with built-in filter PA1.

The power supply through hole 15 and the dielectric filter 31 may be electrically connected on the surface of the base 11 instead of electrically inside the base 11.

FIG. 4 is a perspective view showing a patch antenna PA3 with a built-in filter according to a third embodiment of the present invention.

FIG. 5 shows a patch antenna PA with a built-in filter.
FIG. 3 is a perspective view showing the base 11 with the base 11 omitted.

The patch antenna PA3 with a built-in filter
The point that two sets of antennas are provided on one base 11 is mainly different from the patch antennas PA1 and PA2 with a built-in filter.

That is, the patch antenna PA with a built-in filter
3 includes a base 11, radiation conductors 12a and 12b, a ground conductor 13, feed-through holes 15a and 15b, a triplate-type dielectric filter 32, a capacitor electrode pattern 16b, and a short-circuit pin 25. .

The power supply through holes 15a and 15b are connected to the radiating conductors 12a and 12b inside the base body. The triplate type dielectric filter 32 has a GND 18 on a surface parallel to the radiating electrodes 12a and 12b. , And is a duplexer or a band splitter. The capacitor electrode pattern 16b is a pattern for capacitively coupling the power supply through holes 15a and 15b and the dielectric filter 32.

In the case of the patch antenna PA3, the short-circuit pin 2 is connected between the radiation conductors 12a and 12b and the ground conductor 13.
5 is provided, and a quarter-wave resonance structure is provided to achieve miniaturization. This concept is the same as that of the inverted F-shaped patch antenna.

In the patch antenna PA3, when the dielectric filter 32 is a duplexer or a band splitter that handles a plurality of frequencies, those components required for a dual or triple device are replaced with the patch antenna PA3.
There is no need to prepare separately. Therefore, the entire set including the patch antenna PA3 can be further reduced in size.

In the patch antenna PA3, the base material, electrode material, substrate forming method, terminal configuration method, and the like used are the same as those in the case of the filter built-in patch antenna PA1.

The patch antenna PA with a built-in filter
A plurality of 1, PA2 and PA3 may be arranged and used as an array antenna.

FIG. 6 shows a patch antenna PA with a built-in filter.
FIG. 3 is a diagram showing an equivalent circuit of No. 1;

In the patch antenna PA1 with a built-in filter, the antenna section and the filter 30 are capacitively coupled.

FIG. 7 shows a patch antenna PA with a built-in filter.
2 is a diagram illustrating an equivalent circuit of FIG.

In the filter built-in patch antenna PA2, the antenna section and the filter 31 are directly connected by a conductor.

An optimum connection may be selected from the direct connection and the capacitance connection according to the impedance, peripheral circuit, use state, and the like.

Patch antennas PA1 and PA with built-in filter
2. In PA3, as shown in FIGS. 1 to 5, by incorporating (integrating) a filter inside the patch antenna, parts and sets can be downsized, and mounting of the antenna and filter is easy. , The number of parts can be reduced, and the design of the set maker becomes easy.

Further, in each of the above embodiments, it is possible to suppress the characteristic deterioration due to the miniaturization of the antenna itself and to secure a large volume in the filter portion, so that the characteristics can be improved and the wiring can be routed. Since the length can be shortened, characteristic deterioration can be suppressed.

FIG. 8 is a view for explaining the point of "suppressing characteristic deterioration due to miniaturization of the antenna itself" in the above embodiment.

Referring to FIG. 8, a conventional patch antenna PA
The size of the radiation conductor 12 at 10 is approximately λ / (2 ·
ε ^1/2 ). In contrast, in the filter-equipped patch antenna PA2, the GND conductor 18 of the filter 31
Since the distribution capacitance 41 can be formed between the radiation conductor 12 and the radiation conductor 12, the area of the radiation conductor 12 can be reduced by the newly generated distribution capacitance 41. However, since the performance of the antenna largely depends on the shape, it is impossible to completely prevent the characteristic deterioration due to the miniaturization.

By the way, if the radiation conductor 12 is bent,
In the above-described embodiment, the state of the radiation conductor 12 itself is flat, and a state close to a square can be ensured. Can be minimized.

In order to increase the capacitance while maintaining the state of the radiation conductor 12, the ground conductor 13 must be lifted. For example, in the filter-equipped patch antenna PA1 shown in FIG.
Is lifted up, and a coupling capacitance 41 is generated between the lifted GND electrode 18 and the radiation conductor 12. In this case, the dielectric filter 30 is formed using the space between the GND electrode 18 and the ground conductor 13.

In this case, by forming the radiation electrode 12 and the surface of the GND electrode 18 of the built-in dielectric filter 30 in parallel, a capacitance 41 is provided between the radiation electrode 12 and the GND electrode 18. Can be ideally configured. That is, the capacity 41 can be configured more efficiently with respect to the occupied volume and area.

From the same idea as above, the filters 31, 3
2 are formed, and the patch antennas PA2 and P2
A3 is configured.

[0054] Regarding the above-mentioned point "a large volume can be obtained in the filter portion, the characteristics can be improved", the filter at the front end of the mobile communication usually requires a low loss. High Q is required for the part. The most effective way to increase Q is to secure a sufficient size. However, a sufficient space cannot be ensured in an actual set, so that at present the design must be designed with a low Q.

In this regard, by adopting the structure of the above embodiment, the patch antenna which is originally made of a dielectric has a side of about λ / 2, so that an empty space inside the patch antenna is reduced. It is quite large, and this empty space can be reserved as a filter.

Thus, the length of the resonator portion of the dielectric filter 31 can be made closer to λ / 4, so that a higher Q value can be obtained. by this,
The characteristics of the dielectric filter can be improved.

Further, regarding the above-mentioned point “the wiring can be shortened so that the characteristic deterioration can be suppressed”, if a front-end filter is formed inside the antenna, the distance between them can be minimized. Since it can be set to the limit, deterioration of characteristics can be minimized.

Further, as shown in FIG. 3, by adopting a structure in which the chip type filter 31 is mounted from the back surface, each characteristic can be selected, so that the process yield can be increased. Further, at the time of design, adjustment with individual components becomes possible, so that design time can be reduced.

Further, as shown in FIGS. 4 and 5, by making the antenna have a dual or more structure, the patch antenna can be made dual and the band can be widened while securing the above-mentioned effects.

Further, by using a dielectric filter as a duplexer or a band splitter, it is not necessary to prepare those parts required for the dual or triple device in portions other than the filter built-in patch antennas PA1, PA2 and PA3. In addition, the set including the filter built-in patch antenna can be further reduced in size. Further, isolation between transmission and reception in wireless communication and isolation between dual bands can be improved.

[0061]

According to the present invention, it is possible to easily reduce the size of a patch antenna to which a filter is added, and to cause deterioration in characteristics such as narrowing of a band and reduction in radiation efficiency due to the reduction in size. There is an effect that there is no.

[Brief description of the drawings]

FIG. 1 is an oblique perspective view showing a filter-equipped patch antenna PA1 according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the patch antenna with built-in filter PA1.

FIG. 3 is a cross-sectional view illustrating a filter-equipped patch antenna PA2 according to a second embodiment of the present invention.

FIG. 4 is a perspective oblique view showing a patch antenna with built-in filter PA3 according to a third embodiment of the present invention.

FIG. 5 shows a patch antenna PA3 with a built-in filter.
It is a perspective view which omits and shows a base.

FIG. 6 is a diagram illustrating an equivalent circuit of the patch antenna with built-in filter PA1.

FIG. 7 is a diagram showing an equivalent circuit of the patch antenna PA2 with a built-in filter.

FIG. 8 is a diagram for explaining the point of “suppressing characteristic deterioration due to miniaturization of the antenna itself” in the embodiment.

FIG. 9 is a sectional view showing a conventional patch antenna PA10.

FIG. 10 is a front view showing a conventional patch antenna PA10.

[Explanation of symbols]

PA1, PA2, PA3: Patch antenna with a built-in filter, 11: Base, 12: Radiating conductor, 13: Ground conductor, 14: Power supply terminal, 15: Power supply through hole, 16: Capacitor electrode pattern, 16a: Internal electrode pattern, 16b ... capacitor electrode pattern, 17 ... internal conductor, 18 ... GND electrode, 19 ... external connection conductor, 21 ... printed circuit board, 22 ... ground pattern, 23 ... wiring pattern, 25 ... short-circuit pin, 30 ... built-in dielectric filter, 31: chip type filter, 32: dielectric filter, 41: coupling capacitance.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01Q 23/00 H01Q 23/00 H04B 1/18 H04B 1/18 A F-term (Reference) 5J006 HB03 HB22 5J021 AA01 AB06 CA06 FA23 GA08 HA05 HA10 JA07 5J045 AA05 DA10 EA07 GA08 HA03 MA07 NA01 5J046 AA03 AA19 AB13 PA07 5K062 AB00 AC00 AC01 BC00 BC01 BF00

Claims (4)

[Claims] 1. a base made of a dielectric material; a radiation conductor provided on one surface of the base; and a ground conductor provided on a surface opposite to the one surface;
A feed through hole for feeding the radiating conductor; a dielectric filter having a GND plane on a plane parallel to the radiating conductor and provided inside the base; A patch antenna with a built-in filter, wherein the dielectric filter is electrically connected inside the base. 2. A base made of a dielectric material; a radiation conductor provided on one surface of the base; and a ground conductor provided on a surface facing the one surface;
A power supply through hole for supplying power to the radiation conductor; a recess provided on a part of the base on the ground conductor side; a chip provided inside the recess and provided in parallel with the radiation conductor A dielectric filter of the type, most of the bottom surface of the concave portion is a GND electrode, and the power supply through-hole and the dielectric filter are electrically connected inside or on the surface of the base. A patch antenna with a built-in filter. 3. The patch antenna with a built-in filter according to claim 1, wherein two or more radiating conductors are provided, and each radiating conductor is connected to a feed through hole. 4. The patch antenna according to claim 3, wherein the dielectric filter is a duplexer or a band splitter that handles two or more frequencies.