Patent Description:
In some antenna devices, components of an RF circuit are installed inside an antenna unit. Such a conventional antenna device is disclosed in, for example, Patent Literature <NUM>.

Patent Literature <NUM>: <CIT>
<CIT> discloses a module with an antenna, the module comprises a base body, a patch conductor constructed on one surface of the base body, a GND conductor disposed on the surface of the base body or inside the base body so as to face the patch conductor, and a signal processing circuit which is installed on the surface of the patch conductor, makes the surface of the patch conductor to be GND and processes a signal to be transmitted by the patch conductor or a signal received by the patch conductor. <CIT> provides a shielding module integrating antenna and integrated circuit component, which comprises an artificial magnetic conductor board, an antenna, a common ground face, a plurality of first via holes, a shielding slot, a plurality of second via holes, and an IC component. The IC component is embedded in the shielding slot formed between the common ground face and surrounded by the plurality of second via holes of the artificial magnetic conductor board. <CIT> discloses a structure for achieving a nested connection between an antenna and a circuit, comprising a surface wave suppression antenna, a chip circuit, and a coplanar waveguide pad. The surface wave suppression antenna includes a feed probe, and a silicon-based substrate, metal ground plane, dielectric layer, and radiating patch that are layered from bottom to top. A short-circuited concentric ring is arranged on the radiating patch, and it is concentric with the radiating patch. The radiating patch is connected to the metal ground plane through the short-circuited concentric ring. A slotted portion is provided in the part of the radiating patch inside the short-circuited concentric ring, which is used for placing the chip circuit. One end of the feed probe is connected to the radiating patch. The coplanar waveguide pad includes a ground plate arranged on the metal ground plane, and a signal line connected to the other end of the feed probe.

In the antenna device disclosed in Patent Literature <NUM>, components of an RF circuit are provided in a space inside an annular patch antenna including a patch conductor and a GND conductor. For this reason, in the antenna device disclosed in Patent Literature <NUM>, the patch conductor and the GND conductor are larger than necessary, which may lead to an increase in size of the device.

The present disclosure has been made to solve the above problem, and an object of the present disclosure is to provide an antenna device that does not require a space for installing an RF circuit in the space inside the patch antenna, so that the size of the device can be reduced.

An antenna device according to the present invention is defined in claim <NUM>.

According to the present disclosure, with the above configuration, it is possible to downsize the device since a space for installing an RF circuit is not required in a space inside a patch antenna.

To describe the present disclosure further in detail, embodiments for carrying out the present disclosure will be described below with reference to the accompanying drawings.

An antenna device <NUM> according to a first embodiment will be described with reference to <FIG>. <FIG> is a plan view illustrating the configuration of the antenna device <NUM> according to the first embodiment. <FIG> is a plan view illustrating a state in which an RF circuit <NUM> is removed from the antenna device <NUM>. <FIG> is a cross-sectional view viewed along arrows III-III in <FIG>.

The antenna device <NUM> includes a substrate <NUM>, a GND conductor <NUM>, GND pins <NUM>, a patch conductor <NUM>, a coplanar line <NUM>, an RF circuit <NUM>, mounted components 41a and 41b, a signal line <NUM>, and a power supply line <NUM>.

The substrate <NUM> is formed of an insulating material such as resin, ceramic, or a hybrid material obtained by combining resin and ceramic. The substrate <NUM> has a rectangular shape in plan view and has a predetermined thickness.

The GND conductor <NUM> is provided inside the substrate <NUM>. The GND conductor <NUM> is provided between the top face of the substrate <NUM> and the lower face of the substrate <NUM>. The GND conductor <NUM> is formed into a flat plate shape and has a size substantially equal to the size of the substrate <NUM>.

The patch conductor <NUM> is provided on the top face of the substrate <NUM>. That is, the lower face of the patch conductor <NUM> is attached to the top face of the substrate <NUM>. The patch conductor <NUM> has, for example, a circular shape. The patch conductor <NUM> is provided in such a manner as to face the GND conductor <NUM>.

The plurality of GND pins <NUM> is provided inside the substrate <NUM>. These GND pins <NUM> connect the GND conductor <NUM> and the patch conductor <NUM>.

The coplanar line <NUM> is a conductor region surrounded by linear slits on three sides thereof in the patch conductor <NUM>. In this manner, the coplanar line <NUM> is linearly formed on a region inside the three continuous slits in the patch conductor <NUM>. In the coplanar line <NUM>, a feeding point P connecting the patch conductor <NUM> and the RF circuit <NUM> is formed. Meanwhile, the GND pins <NUM> are connected to a region outside the three continuous slits in the patch conductor <NUM>.

The RF circuit <NUM> is provided at the central portion on the top face of the patch conductor <NUM>. That is, the lower face of the RF circuit <NUM> is attached to the top face of the patch conductor <NUM>. The RF circuit <NUM> is, for example, a low-noise amplifier circuit. The RF circuit <NUM> is surrounded by a plurality of GND pins <NUM> and shielded by the plurality of GND pins <NUM>. In other words, the plurality of GND pins <NUM> prevent intrusion of radio waves from the outside of the antenna device <NUM> into the RF circuit <NUM> and leakage of noise from the RF circuit <NUM> to the outside of the antenna device <NUM>.

Note that the RF circuit <NUM> is surrounded by a plurality of GND pins <NUM> farthest radially outward from the center of the patch conductor <NUM> among the plurality of GND pins <NUM>. A radially inner region with respect to the plurality of GND pins <NUM> surrounding the circumference of the RF circuit <NUM> in this manner is hereinafter referred to as an inner region <NUM>.

The mounted components 41a and 41b are provided on the lower face of the substrate <NUM>. That is, the top faces of the mounted components 41a and 41b are attached to the lower face of the substrate <NUM>.

The signal line <NUM> is provided inside the substrate <NUM>. The signal line <NUM> connects the RF circuit <NUM> and the mounted component 41a. Incidentally, the signal line <NUM> penetrates through the GND conductor <NUM> and the patch conductor <NUM> without being in contact with them. Therefore, the mounted component 41a can receive a signal output from the RF circuit <NUM> via the signal line <NUM>.

Moreover, the signal line <NUM> is surrounded by a plurality of GND pins <NUM> and shielded by the plurality of GND pins <NUM>. In other words, the plurality of GND pins <NUM> prevents intrusion of radio waves from the outside of the antenna device <NUM> into the signal line <NUM> and leakage of noise from the signal line <NUM> to the outside of the antenna device <NUM>.

The power supply line <NUM> is provided inside the substrate <NUM>. The power supply line <NUM> connects the RF circuit <NUM> and the mounted component 41b. Incidentally, the power supply line <NUM> penetrates through the GND conductor <NUM> and the patch conductor <NUM> without being in contact with them. Therefore, the mounted component 41b can supply power to the RF circuit <NUM> via the power supply line <NUM>.

Moreover, the power supply line <NUM> is surrounded by a plurality of GND pins <NUM> and shielded by the plurality of GND pins <NUM>. In other words, the plurality of GND pins <NUM> prevents intrusion of radio waves from the outside of the antenna device <NUM> into the power supply line <NUM> and leakage of noise from the power supply line <NUM> to the outside of the antenna device <NUM>.

Next, a case where the antenna device <NUM> operates as a reception antenna device will be described.

First, when receiving a radio wave, the patch conductor <NUM> generates a high-frequency signal corresponding to the radio wave. Next, the patch conductor <NUM> transmits the generated high-frequency signal to the RF circuit <NUM> via the coplanar line <NUM>. In this case, the RF circuit <NUM> amplifies the high-frequency signal and transmits the amplified high-frequency signal to the mounted component 41a via the signal line <NUM>. In addition, power supply to the RF circuit <NUM> is performed by the mounted component 41b to the RF circuit <NUM> via the power supply line <NUM>.

Incidentally, an arrow illustrated in <FIG> indicates the direction of a line of electric force L. As illustrated in <FIG>, no current flows in the inner region <NUM> surrounded by the GND pins <NUM> since the circumference of the inner region <NUM> is short-circuited by the GND pins <NUM>. That is, the inner region <NUM> is shielded by the GND pins <NUM>. In the antenna device <NUM>, the RF circuit <NUM>, the signal line <NUM>, and the power supply line <NUM> are provided in the inner region <NUM> surrounded by the GND pins <NUM>. Therefore, intrusion of radio waves from the outside of the antenna device <NUM> into the RF circuit <NUM>, the signal line <NUM>, and the power supply line <NUM> provided in the inner region <NUM> is prevented.

Furthermore, the inner region <NUM> of the patch conductor <NUM> is connected to the GND conductor <NUM> via a plurality of GND pins <NUM>. Therefore, the antenna device <NUM> can use the inner region <NUM> as a mounting space for the RF circuit <NUM>.

It is based on the premise that the RF circuit <NUM> is used in a high-frequency band of several tens of GHz band. In the antenna device <NUM>, in the high-frequency band, an installation face for installing the RF circuit <NUM> is a ground face (top face of the patch conductor <NUM>) having a large wavelength ratio and no holes. Therefore, the antenna device <NUM> can reduce unnecessary coupling due to radio waves radiated from the antenna device <NUM> to the outside and the influence of noise from the outside of the antenna device <NUM>.

Note that the above description of the operation of the antenna device <NUM> relates to a case where the antenna device <NUM> operates as a reception antenna device, however, the antenna device <NUM> can also operate as a transmission antenna device. Even in a case where the antenna device <NUM> operates as a transmission antenna device, it is possible to achieve an effect equivalent to that in the case where the antenna device operates as a reception antenna device.

As described above, the antenna device <NUM> according to the first embodiment includes: the patch conductor <NUM> provided on the substrate <NUM>; the GND conductor <NUM> provided in the substrate <NUM> in such a manner as to face the patch conductor <NUM>; the GND pins <NUM> that are provided in the substrate <NUM> and that connect the patch conductor <NUM> and the GND conductor <NUM>; and the RF circuit <NUM> provided on a first face of the patch conductor <NUM> opposite to a second face of the patch conductor <NUM>, the second face being attached to the substrate <NUM>, the RF circuit <NUM> being provided in such a manner as to be surrounded by the GND pins <NUM>. Therefore, the antenna device <NUM> does not require a space for installing the RF circuit <NUM> in a space inside the patch antenna, so that the size of the device can be reduced.

An antenna device <NUM> according to a second embodiment will be described with reference to <FIG> is a cross-sectional view illustrating the configuration of the antenna device <NUM> according to the second embodiment.

As illustrated in <FIG>, the antenna device <NUM> according to the second embodiment has a configuration in which a shielding case <NUM> is added to the configuration of the antenna device <NUM> according to the first embodiment.

The shielding case <NUM> is formed of a metal material. The shielding case <NUM> covers the circumference of the RF circuit <NUM>. Such a shielding case <NUM> is electrically connected to the top face of the patch conductor <NUM> using, for example, solder, a conductive adhesive, or the like. That is, the shielding case <NUM> covers the outside of the entire RF circuit <NUM> with the patch conductor <NUM> serving as the GND. Moreover, the shielding case <NUM> is not electrically connected to the coplanar line <NUM>.

Specifically, as long as the shielding case <NUM> covers the entire RF circuit <NUM>, the shielding case <NUM> may cover the entire coplanar line <NUM> or partially cover the coplanar line <NUM>. In a case where the shielding case <NUM> partially covers the coplanar line <NUM>, the shielding case <NUM> has a cutout portion that straddles the coplanar line <NUM> so as not to be in electrical contact with the coplanar line <NUM>.

The antenna device <NUM> can improve the shieldability of the RF circuit <NUM> by covering the RF circuit <NUM> with the shielding case <NUM> in the above manner. That is, the shielding case <NUM> prevents intrusion of radio waves from the outside of the antenna device <NUM> into the RF circuit <NUM> and leakage of noise from the RF circuit <NUM> to the outside of the antenna device <NUM>.

Note that, in the antenna device <NUM>, metal plating may be applied to the surface of the RF circuit <NUM> instead of including the shielding case <NUM>. In this case, the surface of the metalplated RF circuit <NUM> is short-circuited via the patch conductor <NUM>. By metalizing the surface of the RF circuit <NUM> in this manner, the shieldability of the RF circuit <NUM> can be improved in the antenna device <NUM>.

As described above, the antenna device <NUM> according to the second embodiment includes the shielding case <NUM> that covers the outside of the RF circuit <NUM> and that is connected to the patch conductor <NUM>. Therefore, the antenna device <NUM> can improve the shieldability of the RF circuit <NUM>.

Furthermore, in the antenna device <NUM>, the surface of the RF circuit <NUM> is plated with metal. Therefore, the antenna device <NUM> can improve the shieldability of the RF circuit <NUM>.

An antenna device <NUM> according to a third embodiment will be described with reference to <FIG> is a plan view illustrating the configuration of the antenna device <NUM> according to the third embodiment.

As illustrated in <FIG>, the antenna device <NUM> according to the third embodiment has a configuration that includes two coplanar lines 31a and 31b instead of one coplanar line <NUM> in the antenna device <NUM> according to the first embodiment.

The patch conductor <NUM> includes the coplanar lines 31a and 31b. The coplanar line 31a and the coplanar line 31b are provided in such a manner as to be perpendicular to each other. Each of the coplanar lines 31a and 31b has a feeding point P. The antenna device <NUM> can excite a circularly polarized wave by feeding power through the feeding points P of the coplanar lines 31a and 31b which have a phase difference of <NUM>° therebetween as described above.

Note that the antenna device <NUM> may include three or more coplanar lines. In this case, in the antenna device <NUM>, the coplanar lines can be provided at desired positions by appropriately setting the phase differences between adjacent coplanar lines.

As described above, the antenna device <NUM> according to the third embodiment includes two or more coplanar lines 31a and 31b that are provided for the patch conductor <NUM> and that connect the patch conductor <NUM> and the RF circuit <NUM>. The two coplanar lines 31a and 31b are provided in such a manner as to be perpendicular to each other. Therefore, the antenna device <NUM> can excite a circularly polarized wave.

An antenna device <NUM> according to a fourth embodiment will be described with reference to <FIG> is a plan view illustrating the configuration of the antenna device <NUM> according to the fourth embodiment.

The antenna device <NUM> according to the fourth embodiment has a configuration in which a cutout portion 30a is added to the configuration of the antenna device <NUM> according to the first embodiment.

As illustrated in <FIG>, the patch conductor <NUM> has the cutout portion 30a. The cutout portion 30a is for implementing circular polarization.

As described above, the antenna device <NUM> according to the fourth embodiment includes the cutout portion 30a provided in the outer circumferential portion of the patch conductor <NUM>. Therefore, the antenna device <NUM> can implement circular polarization by the cutout portion 30a.

An antenna device <NUM> according to a fifth embodiment will be described with reference to <FIG> is a plan view illustrating the configuration of the antenna device <NUM> according to the fifth embodiment.

The antenna device <NUM> according to the fifth embodiment has a configuration that includes a λ/<NUM> conversion line <NUM> instead of the coplanar line <NUM> of the antenna device <NUM> according to the first embodiment.

As illustrated in <FIG>, the patch conductor <NUM> includes the λ/<NUM> conversion line <NUM>. The λ/<NUM> conversion line <NUM> is a conductor region surrounded by slits on both sides in the width direction in the patch conductor <NUM>. The λ/<NUM> conversion line <NUM> is formed into a rectangular shape in the inner portion between the slits facing each other in the patch conductor <NUM> as described above. The λ/<NUM> conversion line <NUM> connects the patch conductor <NUM> and the RF circuit <NUM>. Therefore, the λ/<NUM> conversion line <NUM> facilitates impedance matching between the patch conductor <NUM> and the RF circuit <NUM> as compared with the case where the coplanar line <NUM> is provided.

In addition, since the line width of the λ/<NUM> conversion line <NUM> can be set desirably, the value of the impedance can be selected desirably. Therefore, in the antenna device <NUM>, it is possible to design an antenna in which the patch conductor <NUM> and the RF circuit <NUM> are set to have desired impedance values.

Note that the antenna device <NUM> includes the rectangular λ/<NUM> conversion line <NUM>, however, the shape of the λ/<NUM> conversion line <NUM> is not limited thereto. The λ/<NUM> conversion line <NUM> may have, for example, a tapered shape in which the line width gradually increases as it is closer to an outer side in the radial direction of the patch conductor <NUM>. By including the tapered λ/<NUM> conversion line <NUM>, the antenna device <NUM> can reduce the influence on a reflection coefficient of a radio wave due to a steep change in the line width.

Furthermore, the antenna device <NUM> may include a plurality of λ/<NUM> conversion lines <NUM>. In this case, in the antenna device <NUM>, the λ/<NUM> conversion lines <NUM> can be provided at desired positions by appropriately setting phase differences between adjacent λ/<NUM> conversion lines <NUM>.

As described above, the antenna device <NUM> according to the fifth embodiment includes the λ/<NUM> conversion line <NUM> that is provided for the patch conductor <NUM> and that connects the patch conductor <NUM> and the RF circuit <NUM>. The λ/<NUM> conversion line <NUM> is formed in such a manner that a portion closer to the outside of the patch conductor <NUM> has a wider line width. Therefore, in the antenna device <NUM>, it is possible to set the patch conductor <NUM> and the RF circuit <NUM> to have desired impedance values.

An antenna device <NUM> according to a sixth embodiment will be described with reference to <FIG> is a plan view illustrating the configuration of the antenna device <NUM> according to the sixth embodiment.

The antenna device <NUM> according to the sixth embodiment has a configuration that includes a feed line <NUM> instead of the coplanar line <NUM> of the antenna device <NUM> according to the first embodiment.

As illustrated in <FIG>, the patch conductor <NUM> includes the feed line <NUM>. The feed line <NUM> is a conductor region that is a portion remaining after cutting out parts of the patch conductor <NUM>. Two portions obtained by cutting out the parts from the patch conductor <NUM> are hollow portions 30b. Furthermore, a part of the feed line <NUM> forms a microstrip line. As described above, a part of the feed line <NUM> is a microstrip line, and thus impedance matching between the patch conductor <NUM> and the RF circuit <NUM> is easily achieved by providing a stub in the feed line <NUM>, for example.

Note that the antenna device <NUM> may include a plurality of feed lines <NUM>. In this case, in the antenna device <NUM>, the feed lines <NUM> can be provided at desired positions by appropriately setting phase differences between adjacent feed lines <NUM>.

As described above, the antenna device <NUM> according to the sixth embodiment includes the feed line <NUM> that is provided for the patch conductor <NUM> and that connects the patch conductor <NUM> and the RF circuit <NUM>. The feed line <NUM> is formed by cutting out parts of the patch conductor <NUM>. Therefore, in the antenna device <NUM>, the values of impedance can be easily matched between the patch conductor <NUM> and the RF circuit <NUM>.

Note that the present disclosure can include a flexible combination of the embodiments, modification of any component of the embodiments, or omission of any component in the embodiments within the scope of the disclosure.

Since an antenna device according to the present disclosure includes an RF circuit provided in such a manner as to be surrounded by GND pins, a space for installing the RF circuit is not required in a space inside the patch antenna, so that the size of the device can be reduced. Therefore, the antenna device is suitable for use as an antenna device or the like.

Claim 1:
An antenna device (<NUM> to <NUM>) comprising:
a patch conductor (<NUM>) provided on a first face of a substrate (<NUM>);
a GND conductor (<NUM>) provided inside the substrate in such a manner as to face a second face of the patch conductor;
an RF circuit (<NUM>) provided on a first face of the patch conductor opposite to the second face of the patch conductor, the second face being attached to the substrate,
and further comprising GND pins (<NUM>) that are provided inside the substrate, and a signal line (<NUM>) and a power supply line (<NUM>) that are provided inside the substrate,
the GND pins extending from the GND conductor to the second face of the patch conductor, the patch conductor and the GND conductor being electrically connected to each other via the GND pins,
the patch conductor having an inner region short-circuited by the GND pins and used as a mounting space for the RF circuit,
the signal line and the power supply line being surrounded by the GND pins and shielded by the GND pins.