Antenna device, transmitter, and radar

Abstract

ANTENNA DEVICE, TRANSMITTER, AND RADAR Embodiments of the present invention provide an antenna device (10) capable of suppressing unwanted radiation in a center feed. The antenna device (10) includes a dielectric substrate (2) and a conductor pattern (3, 3A, 3B, 3C, 3D, 3E, or 3F) formed on the dielectric substrate (2). The conductor pattern (3, 3A, 3B, 3C, 3D, 3E, or 3F) includes a series antenna array (4). The series antenna array (4) includes a plurality of patch antennas (41, 42, 43, 44, and 45) and a plurality of transmission lines (46, 47, 48, and 49) connecting adjacent patch antennas. The conductor pattern (3, 3A, 3B, 3C, 3D, 3E, or 3F) further includes an input / output line (5) configured to supply power to the series antenna array (4) through a patch antenna (42, 43, or 44) that is not one of patch antennas (41 or 45) at both ends of the series antenna array (4). (FIG. 2)

Description

ANTENNA DEVICE, TRANSMITTER, AND RADAR

[0001] The present invention generally relates to devices and apparatuses for transmitting and receiving radiation signals. More specifically, the present invention relates to an antenna device, transmitter, and radar capable of suppressing unwanted radiation in a center feed.Background

[0002] Patch array antennas are a type of antenna that consists of multiple patch antennas arranged in a specific pattern. Each patch antenna is a flat, rectangular, or circular piece of metal that is printed on a dielectric substrate. The dielectric substrate is then mounted on a ground plane. When a Radio-Frequency (RF) signal is applied to a patch antenna, the patch antenna radiates electromagnetic waves. By arranging multiple patch antennas in an array, the signaling performance can be improved in terms of gain, directivity, and bandwidth. Patch array antennas are widely used in a variety of applications, such as satellite communications, radar systems, and wireless communication systems.

[0003] CN106972244B discloses a vehicle-mounted radar array antenna consisting of a radiation plate array and an impedance-matching network on the same plane. The radiation plate array is symmetrically arranged around the impedance-matching network, which serves as the central axis. The impedance matching network, composed of microstrip line traces, performs impedance matching, phase shifting, and phase adjustment. Furthermore, the impedance matching network includes a power divider, an impedance converter, and phase shift control sections, enabling beam adjustment, power distribution, and reduced loss. The antenna design reduces electromagnetic interference, duty cycle, and adverse effects on other RF circuits. The single-feed structure and microstrip transmission line minimize energy consumption and transmission loss.

[0004] EP2950390A1 discloses a patch array antenna and a radar signal transmitting and receiving apparatus. The patch array antenna includes multiple unit elements, each having a patch creating a radiation pattern and feeders with varying widths. The widths of the feeders are adjusted according to the radiant quantity of each unit element to secure a side lobe level. The antenna can be implemented as a microstrip antenna with a series-fed structure. The radar signal transmitting and receiving apparatus includes a radar signal generating unit and the patch array antenna. The invention provides several benefits, including easy adjustment of the side lobe level, increased design convenience, simplified etching process, reduced component count, and lower production cost. The antenna can be used in various applications, including vehicle-mounted radar systems, and can output polarized wave signals with predetermined angles.

[0005] For the patch array antennas, a feeding system called center feed is sometimes used. Normally, in the center feed, as shown in FIG. 1, a phase shifter S consisting of a meander line is provided between the feeding position P of the transmission line L and the patch antenna B on one side, so that the transmission line L feeds the patch antennas A and B on both sides with a phase difference of 180 degrees. However, the phase shifter S composed of a meander line causes unwanted radiation because the meander line is bent. Therefore, there is a need in the art for an antenna device, a transmitter, and a radar capable of suppressing unwanted radiation in a center feed.

[0006] Various embodiments of the present invention provide an antenna device, a transmitter equipped with the antenna device, and a radar equipped with the antenna device, capable of suppressing unwanted radiation in a center feed.

[0007] According to a first aspect of the present invention, there is provided an antenna device including a dielectric substrate and a conductor pattern formed on the dielectric substrate. The conductor pattern includes a series antenna array. The series antenna array includes a plurality of patch antennas arranged in an alignment direction and a plurality of transmission lines. Each of the plurality of transmission lines connects adjacent patch antennas of the plurality of patch antennas. The conductor pattern further includes an input / output line configured to supply power to the series antenna array. The input / output line is connected to a side extending in a width direction, through which a transmission line, of the plurality of transmission lines, is connected to a patch antenna that is not one of patch antennas at both ends of the series antenna array. Thus, by directly connecting the input / output line to the patch antenna, unnecessary radiation can be suppressed by omitting a phase shifter.

[0008] In one embodiment, the transmission line may be connected on one side deviated from a center in a width direction of the side of the patch antenna, and the input / output line may be connected to an opposite side deviated from the center in the width direction of the side of the patch antenna. Thus, the influence of the input / output line on the transmission line can be suppressed.

[0009] In one embodiment, the input / output line may include a first line section connected to one side in one direction of one patch antenna of the series antenna array and a second line section connected to one side in the same direction of another patch antenna of the series antenna array. Furthermore, the first line section and the second line section may either have same lengths or difference between respective lengths of the first line section and the second line section may be an integer number multiple of a wavelength of a fundamental wave. The first line section and the second line section are set to lengths that refrain a phase difference from occurring between fundamental waves inputted to the first and second patch antennas. Thus, a part of unnecessary resonance can be suppressed.

[0010] In one embodiment, the antenna device further may include a connecting line configured to connect a side of the one patch antenna to which a transmission line, of the plurality of transmission lines, is connected, and a side of the other patch antenna to which another transmission line, of the plurality of transmission lines, is connected. This makes it possible to suppress a part of unnecessary resonance.

[0011] In one embodiment, the input / output line may include a first line section connected to one side in one direction of one patch antenna of the series antenna array and a second line section connected to one side in an opposite direction of another patch antenna of the series antenna array. Furthermore, the first line section and the second line section may be set to respective lengths that cause a phase difference of half wavelength between fundamental waves input to the one patch antenna and the other patch antenna. This makes it possible to suppress a part of unnecessary resonance.

[0012] In one embodiment, the input / output line may be disposed between sides facing the width direction and extending in the alignment direction of a patch antenna to which the input / output line is connected. This makes it possible to suppress the widthwise spread.

[0013] In one embodiment, a width of the patch antenna to which the input / output line is connected may be wider than respective widths of the patch antennas at both ends of the series antenna array. This makes it possible to increase the coupling amount between the series antenna array and the input / output line.

[0014] According to another aspect of the present invention, there is provided a transmitter that includes the antenna device as described in the aforementioned embodiments. This makes it possible to realize a transmitter including an antenna device that suppresses unnecessary radiation.

[0015] According to another aspect of the present invention, there is provided a radar that includes the antenna device as described in the aforementioned embodiments. This makes it possible to realize a radar including an antenna device in which unwanted radiation is suppressed.Advantageous Effects of the Invention

[0016] According to the present invention, unwanted radiation can be suppressed in a center feed.

[0017] The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. It should be noted that in the accompanying drawings, like or same reference numerals refer to identical or functionally similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the disclosed embodiments and, together with the detailed description of the invention, serve to explain the principles of the disclosed embodiments. FIG. 1 illustrates a conventional conductor pattern, in accordance with prior art; FIG. 2 illustrates an example of a radar, in accordance with an embodiment of the present invention; FIG.3 illustrates an example of an antenna device, in accordance with an embodiment of the present invention; FIG. 4 illustrates an example of a conductor pattern, in accordance with a first embodiment of the present invention; FIG. 5 illustrates another example of the conductor pattern, in accordance with the first embodiment of the present invention; FIG. 6 illustrates an example of characteristics of the conductor pattern, in accordance with the first embodiment of the present invention; FIG. 7 illustrates an example of a conductor pattern, in accordance with a second embodiment of the present invention; FIG. 8 illustrates an example of a conductor pattern, in accordance with a third embodiment of the present invention; FIG. 9 illustrates an example of a conductor pattern, in accordance with a fourth embodiment of the present invention; FIG. 10 illustrates an example of a conductor pattern, in accordance with a fifth embodiment of the present invention; FIG. 11 illustrates an example of a conductor pattern, in accordance with a sixth embodiment of the present invention; FIG. 12 illustrates another example of the conductor pattern, in accordance with the sixth embodiment of the present invention; FIG. 13 illustrates a characteristic example of the conductor pattern, in accordance with the first embodiment of the present invention; FIG. 14 illustrates a characteristic example of the conductor pattern, in accordance with the third embodiment of the present invention; and FIG. 15 illustrates a characteristic example of the conductor pattern, in accordance with the fifth embodiment of the present invention.

[0018] The diagrams are for illustration only, which thus is not a limitation of the present invention. Moreover, those skilled in the art will understand that the drawings are not to scale.

[0019] The following is a detailed description of embodiments of the invention depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the invention. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claims.

[0020] In the following description, numerous specific details are outlined in order to provide a thorough understanding of the embodiments of the present invention. It will be apparent to those skilled in the art that embodiments of the present invention may be practiced without some of these specific details. It should be understood that the particular values and configurations discussed in the following non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.

[0021] Various embodiments of the present invention have been described below with reference to the drawings. In this specification and each of the drawings, elements that are the same as those described above with respect to the existing drawings are denoted by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0022] It is to be understood that not necessarily all objects or advantages may be achieved in accordance with any particular embodiment described herein. Thus, for example, those skilled in the art will recognize that certain embodiments may be configured to operate in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0023] All of the processes described herein may be embodied in, and fully automated via, software code modules executed by a computing system that includes one or more computers or processors. The code modules may be stored in any type of non-transitory computer-readable medium or other computer storage device. Some or all the methods may be embodied in specialized computer hardware.

[0024] Many other variations than those described herein will be apparent from this invention. For example, depending on the embodiment, certain acts, events, or functions of any of the algorithms described herein can be performed in a different sequence, can be added, merged, or left out altogether (e.g., not all described acts or events are necessary for the practice of the algorithms). Moreover, in certain embodiments, acts or events can be performed concurrently, e.g., through multi-threaded processing, interrupt processing, multiple processors or processor cores, or on other parallel architectures, rather than sequentially. In addition, different tasks or processes can be performed by different machines and / or computing systems that can function together.

[0025] The various illustrative logical blocks and modules described in connection with the embodiments disclosed herein can be implemented or performed by a machine, such as a processor. A processor can be a microprocessor, but in the alternative, the processor can be a controller, microcontroller, state machine, combination of the same, or the like. A processor can include electrical circuitry configured to process computer-executable instructions. In another embodiment, a processor includes an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable device that performs logic operations without processing computer-executable instructions.

[0026] A processor can also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor (DSP) and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Although described herein primarily with respect to digital technology, a processor may also include primarily analog components. For example, some or all of the signal processing algorithms described herein may be implemented in analog circuitry or mixed analog and digital circuitry. A computing environment can include any type of computer system, including, but not limited to, a computer system based on a microprocessor, a mainframe computer, a digital signal processor, a portable computing device, a device controller, or a computational engine within an appliance, to name a few.

[0027] Conditional language such as, among others, "can", "could", "might" or "may" unless specifically stated otherwise, are otherwise understood within the context as used in general to convey that certain embodiments include, while other embodiments do not include, certain features, elements and / or steps. Thus, such conditional language is not generally intended to imply that features, elements and / or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and / or steps are included or are to be performed in any particular embodiment.

[0028] Disjunctive language such as the phrase "at least one of X, Y, or Z" unless specifically stated otherwise, is otherwise understood with the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and / or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present.

[0029] Any process descriptions, elements, or blocks in the flow diagrams described herein and / or depicted in the attached figures should be understood as potentially representing modules, segments, or members of code which include one or more executable instructions for implementing specific logical functions or elements in the process. Alternate implementations are included within the scope of the embodiments described herein in which elements or functions may be deleted, executed out of order from that shown, or discussed, including substantially concurrently or in reverse order, depending on the functionality involved as would be understood by those skilled in the art.

[0030] Unless otherwise explicitly stated, articles such as "a" or "an" should generally be interpreted to include one or more described items. Accordingly, phrases such as "a device configured to" are intended to include one or more recited devices. Such one or more recited devices can also be collectively configured to carry out the stated recitations. For example, "a processor configured to carry out recitations A, B, and C" can include a first processor configured to carry out recitation A working in conjunction with a second processor configured to carry out recitations B and C. The same holds true for the use of definite articles used to introduce embodiment recitations. In addition, even if a specific number of an introduced embodiment recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations" without other modifiers, typically means at least two recitations or two or more recitations).

[0031] It will be understood by those within the art that, in general, terms used herein, are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to" the term "having" should be interpreted as "having at least" the term "includes" should be interpreted as "includes but is not limited to" etc.).

[0032] For expository purposes, the term "horizontal" as used herein is defined as a plane parallel to the plane or surface of the floor of the area in which the system being described is used or the method being described is performed, regardless of its orientation. The term "floor" can be interchanged with the term "ground" or "water surface." The term "vertical" refers to a direction perpendicular to the horizontal as just defined. Terms such as "above", "below", "bottom", "top", "side", "higher", "lower", "upper", "over" and "under" are defined with respect to the horizontal plane.

[0033] As used herein, the terms "attached", "connected", "mated" and other such relational terms should be construed, unless otherwise noted, to include removable, moveable, fixed, adjustable, and / or releasable connections or attachments. The connections / attachments can include direct connections and / or connections having an intermediate structure between the two components discussed.

[0034] Numbers preceded by a term such as "approximately", "about" and "substantially" as used herein include the recited numbers and also represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms "approximately", "about" and "substantially" may refer to an amount that is within less than 10% of the stated amount. Features of embodiments disclosed herein preceded by a term such as "approximately", "about" and "substantially" as used herein represent the feature with some variability that still performs a desired function or achieves a desired result for that feature.

[0035] Various embodiments of the present invention relate to an antenna device, a transmitter, and a radar. The approach of the present invention will be described hereinafter with reference to FIG. 2 to FIG. 15.

[0036] FIG. 2 illustrates an example of a radar 100, in accordance with an embodiment of the present invention. The radar 100 is an example of a transmitter. The radar 100 includes an antenna device 10, a transceiver 11, a signal processor 12, and a control unit 13. The transceiver 11 includes a modulator and a magnetron and generates a transmission signal by intermittently driving the magnetron with a pulse voltage generated by the modulator in response to a trigger signal from the signal processor 12. The antenna device 10 transmits the transmission signal from the transceiver 11 as a radio wave pulse. The antenna device 10 also converts a received reflected wave into a reception signal. The reception signal from the antenna device 10 passes through a frequency conversion / amplification circuit and a detection circuit included in the transceiver 11, is processed by the signal processor 12 and is sent to the control unit 13 as a digital signal. The radar 100 is applied, for example, to an onboard radar for obstacle detection or collision prevention that transmits and receives millimeter waves. The radar 100 may also be applied, for example, to a marine radar that transmits and receives microwaves.

[0037] FIG. 3 illustrates an example of an antenna device 10, in accordance with an embodiment of the present invention. The antenna device 10 includes a dielectric substrate 2, a conductor pattern 3 formed on a first main surface 21 (a surface visible in the figure) of the dielectric substrate 2, and a ground pattern (not shown) formed on a second main surface opposite to the first main surface 21 of the dielectric substrate 2. The conductor pattern 3 includes a series antenna array 4 and an input / output line 5 for supplying power to the series antenna array 4. The “conductor pattern 3” is a generic name for the conductor patterns 3A to 3F of the embodiments described later. The series antenna array 4 is a series feeding type patch antenna array and includes a plurality of patch antennas 41-45 (also called antenna elements 41-45) arranged in an alignment direction X1-X2 and a plurality of transmission lines 46-49, each transmission line of the plurality of transmission lines 46-49, connecting two adjacent patch antennas of the plurality of patch antennas 41-45. For example, a first transmission line 46 connects the patch antennas 41 and 42, a second transmission line 47 connects patch antennas 42 and 43, a third transmission line 48 connects patch antennas 43 and 44, a fourth transmission line 49 connects patch antennas 44 and 45, and so forth. A number of the plurality of patch antennas 41-45 is not limited to the illustrated example.

[0038] Furthermore, in the series antenna array 4, the plurality of patch antennas 41-45 are arranged alternately in one direction. Thus, the antenna device 10 has strong directivity as a whole. The plurality of transmission lines 46-49 includes high-impedance lines whose impedance is higher than that of the plurality of patch antennas 41-45. The X1-X2 direction shown in FIG. 3 is the alignment direction of the plurality of patch antennas 41-45, the extension direction of the plurality of transmission lines 46-49, and the transmission direction of radio waves in the series antenna array 4. In the following, the X1-X2 direction is simply referred to as the "X direction." In addition, one side of the X direction (in the left direction in FIG. 3) is referred to as the "X1 side," and the other side (in the right direction in FIG. 3) is referred to as the "X2 side."

[0039] The Y1-Y2 direction orthogonal to the X direction is the width direction of the plurality of patch antennas 41-45 and the plurality of transmission lines 46-49. In the following, the Y1-Y2 direction is simply referred to as the "Y direction." In addition, one side of the Y direction (in the upper direction in FIG. 3) is referred to as the "Y1 side," and the other side (in the lower direction in FIG. 3) is referred to as the "Y2 side." In several embodiments, each one of the plurality of patch antennas 41-45 is formed in a rectangular shape and has a length in the transmission direction X corresponding to 1 / 2 wavelength of a fundamental wave of a used frequency. That is, the length in the transmission direction X of each of the plurality of patch antennas 41-45 is almost equal to 1 / 2 wavelength of the fundamental wave.

[0040] An input / output line 5 is connected to a feeding point 9 and supplies the power from the feeding point 9 to a middle portion of the series antenna array 4 (so-called center feed). The feeding point 9 is formed by a through-hole formed in the dielectric substrate 2. The conductor pattern 3 is formed by patterning a metal foil formed on the first main surface 21 of the dielectric substrate 2 by photolithography. Therefore, the plurality of patch antennas 41-45, the plurality of transmission lines 46-49, and the input / output line 5 may also be integrally formed. In the example of FIG. 3, only one series antenna array 4 is shown, but the antenna device 10 may be provided with a plurality of series antenna arrays 4 arranged in the width direction Y. Also, among the plurality of series antenna arrays 4, some of the series antenna arrays 4 may be used for transmission and the other series antenna arrays 4 may be used for reception.

[0041] Incidentally, in the conventional example, as shown in FIG. 1, a phase shifter S consisting of a meander line is provided between a feeding position P of a transmission line L and a patch antenna B on one side, so that the transmission line L feeds a patch antenna A and the patch antenna B on both sides with a phase difference of 180 degrees. As a result, the potentials of the patch antennas A and B are aligned so that one end is a positive potential and the other end is a negative potential, and the radiated power from each patch antenna is synthesized. However, the phase shifter S consisting of the meander line causes unwanted radiation because the line is bent. Therefore, in the embodiment described below, not only the antenna element but also the line itself is in a resonant state, and the resonant state is broken by feeding the line, but the power is directly fed from the radiation edge of the antenna element, which is easier to feed. As a result, unnecessary radiation can be suppressed by omitting the phase shifter, and a standing-wave-excited array antenna with a simple structure can be realized.

[0042] FIG. 4 illustrates an example of a conductor pattern 3A, in accordance with a first embodiment of the present invention. In the conductor pattern 3A, the input / output line 5 may be directly connected to a side to which the plurality of transmission lines 46-49 is connected to any of the patch antennas 42-44. However, the input / output line 5 may not be connected to any side of the patch antennas 41 and 45 at both ends of the plurality of patch antennas 41-45 or the series antenna array 4. The side perpendicular to the transmission direction X and extending in the width direction Y of the plurality of patch antennas 41-45 is also called a radiation edge. In the illustrated example, the input / output line 5 is connected to a side 431 of the center patch antenna 43 on the X1 side to which the transmission line 47 is connected. In other words, two lines of the transmission line 47 and the input / output line 5 are connected to the side 431 on the X1 side of the patch antenna 43. The patch antenna 43 is an antenna element having 1 input and 2 outputs, with the input / output line 5 as an input and the transmission lines 47 and 48 as outputs.

[0043] Thus, even if the conventional phase shifter S (see FIG. 1) is omitted, the potentials of all of the plurality of patch antennas 41-45 can be aligned so that, for example, the side on the X1 side becomes a positive potential and the side on the X2 side becomes a negative potential, or the opposite. In particular, a phase difference of 180 degrees can be provided so that the side 431 on the X1 side of the patch antenna 43 to which the input / output line 5 is connected becomes a positive potential and a side 422 on the X2 side of the patch antenna 42 facing the side 431 becomes a negative potential, or the opposite. Thus, the desired radiation amount can be achieved by combining the radiation power from each of the plurality of patch antennas 41-45 while suppressing unnecessary radiation.

[0044] FIG. 5 illustrates another example of the conductor pattern 3A, in accordance with the first embodiment of the present invention. In this example, 41 patch array antennas are provided in the conductor pattern 3A. FIG. 6 illustrates an example of characteristics of the conductor pattern 3A, in accordance with the first embodiment of the present invention. The horizontal axis represents angle θ (deg), and the vertical axis represents total gain (dB). From this, it can be seen that relatively high directivity is realized.

[0045] As shown in FIGS 4 and 5, in the series antenna array 4, patch antennas closer to the center have a wider width, and patch antennas farther from the center have a narrower width, in order to increase directivity by increasing radiation quantity as the patch antenna closer to the center. The input / output line 5 is connected to a patch antenna with a relatively wide width. For example, as shown in FIG. 4, the width of the center patch antenna 43 is wider than the width of the adjacent patch antennas 42 and 44 and is wider than the width of the patch antennas 41 and 45 at both ends. The input / output line 5 is connected to the widest patch antenna 43. Since the radiation amount of the entire series antenna array 4 depends on the coupling amount of the input / output structure to the series antenna array 4, by connecting the input / output line 5 to the patch antenna with a relatively wide width in the series antenna array 4 and increasing the coupling amount, it is possible to increase the radiation amount of the entire series antenna array 4 and realize a wide area.

[0046] FIG. 7 illustrates an example of a conductor pattern 3B, in accordance with a second embodiment of the present invention. In the conductor pattern 3B, the transmission line 47 is connected offset from the center of the side 431 on the X1 side of the patch antenna 43 on the Y1 side in the width direction Y, and the input / output line 5 is connected offset from the center to the Y2 side. This makes it possible to suppress the influence of the input / output line 5 on the transmission line 47. Among the plurality of transmission lines 46-49, the transmission lines 46 and 48-49 are connected to the center of the plurality of patch antennas 41-45 in the width direction Y, while the transmission line 47, which is connected to the side 431 on the X1 side of the patch antenna 43 together with the input / output line 5, is connected to a position deviated from the center of the patch antenna 42 and 43 in the width direction Y. That is, neither the transmission line 47 nor the input / output line 5 is located in the center of the patch antenna 43 in the width direction Y.

[0047] FIG. 8 illustrates an example of a conductor pattern 3C, in accordance with a third embodiment of the present invention. In the conductor pattern 3C, the input / output line 5 includes a plurality of line sections 52 and 53 branched from a common line section 51. A first line section 52 is connected to a side 421 on the X1 side of the patch antenna 42, and a second line section 53 is connected to a side 441 on the X1 side of the patch antenna 44. The plurality of line sections 52 and 53 are set to a length that refrains a phase difference from occurring between the fundamental waves input to the patch antennas 42 and 44. For example, the plurality of line sections 52 and 53 have the same length. The plurality of line sections 52 and 53 need not have equal lengths, however, in some embodiments, a difference between respective lengths of the line sections 52 and 53 may be an integer number multiple of the wavelength of the fundamental wave.

[0048] Thus, the fundamental wave input from the common line section 51 to the side 421 on the X1 side of the patch antenna 42 and the fundamental wave input from the first line section 52 to the side 441 on the X1 side of the patch antenna 44 are in phase. Not limited to the illustrated example, the first line section 52 may be connected to a side 422 on the X2 side of the patch antenna 42 and the second line section 53 may be connected to a side 442 on the X2 side of the patch antenna 44. The plurality of line sections 52 and 53 may be connected to other patch antennas. The number of the plurality of line sections 52 and 53 may be 3 or more. In the standing-wave excitation type array antenna, as the number of elements increases, many unnecessary resonances occur and the band becomes narrow. The unnecessary resonances are multiplication waves resonating over the entire length of the antenna, and the number of resonance modes increases as the antenna length increases. The third embodiment was made in view of the aforementioned problem, and it is possible to suppress a part of unnecessary resonances by supplying power to a plurality of elements of the conductor pattern 3C.

[0049] FIG. 9 illustrates an example of a conductor pattern 3D, in accordance with a fourth embodiment of the present invention. In the conductor pattern 3D, the first line section 52 is connected to the side 421 on the X1 side of the patch antenna 42, and the second line section 53 is connected to a side 432 on the X2 side of the patch antenna 43. The plurality of line sections 52 and 53 are set so as to have a half wavelength phase difference between the fundamental waves input to the patch antennas 42 and 43. For example, the plurality of line sections 52 and 53 have a half wavelength difference. In several alternate embodiments, the plurality of line sections 52 and 53 may have a difference of a wavelength that is an integer number multiple of one and a half times the wavelength of the fundamental wave. As a result, the fundamental wave input from the common line section 51 to the side 421 on the X1 side of the patch antenna 42 and the fundamental wave input from the first line section 52 to the side 432 on the X2 side of the patch antenna 43 may be in opposite phases. In the fourth embodiment, as in the third embodiment, it is possible to suppress a part of unnecessary resonance.

[0050] FIG. 10 illustrates an example of a conductor pattern 3E, in accordance with a fifth embodiment of the present invention. The conductor pattern 3E further includes a connecting line 6 for connecting the side 422 of the plurality of patch antennas 41-45 to which the transmission line 47 of the patch antenna 42 is connected and the side 442 of the patch antenna 44 to which the transmission line 49 is connected. Specifically, the connecting line 6 connects the side 422 of the patch antenna 42 on the X2 side and the side 442 of the patch antenna 44 on the X2 side and has a length that is an integer number multiple of the wavelength of the fundamental wave. Thus, the potentials of the side 422 of the patch antenna 42 on the X2 side and the side 442 of the patch antenna 44 on the X2 side can be aligned. Thus, in the fifth embodiment as in the third and fourth embodiments, it is possible to suppress a part of the unwanted resonance. Not limited to the illustrated example, the connecting line 6 may connect the side 421 of the patch antenna 42 on the X1 side and the side 441 of the patch antenna 44 on the X1 side and may have a length that is an integer number multiple of the wavelength of the fundamental wave. In addition, the connecting line 6 may be connected to another patch antenna. In addition, the connecting line 6 may be formed between the side 421 of the patch antenna 42 on the X1 side and the side 442 of the patch antenna 44 on the X2 side and may have a length that is an integer number multiple of one and a half times of the wavelength of the fundamental wave. This also makes it possible to suppress part of the unwanted resonance.

[0051] FIG. 11 illustrates an example of a conductor pattern 3F, in accordance with a sixth embodiment of the present invention. In the conductor pattern 3F, the input / output line 5 and the feed point 9 are arranged within the width direction Y of the series antenna array 4. Specifically, the input / output line 5 and the feed point 9 are formed within the width direction Y of the widest patch antenna 43 to which the input / output line 5 is connected. More specifically, the positions of the input / output line 5 and the feed point 9 in the width direction Y are positioned between sides 433 and 434 facing the width direction Y of the patch antenna 43 and extending in the alignment direction X. The input / output line 5 linearly extends from the feed point 9 to the side 431 on the X1 side of the patch antenna 43. The input / output line 5 is formed in parallel with the transmission line 47 connected to the side 431 on the X1 side of the same patch antenna 43. By arranging the input / output line 5 and the feed point 9 within the width direction Y of the series antenna array 4 in this way, the series antenna array 4 can be made compact in the width direction Y, and space saving can be achieved.

[0052] In particular, as shown in FIG. 12, when a plurality of series antenna arrays 4 are arranged in the width direction Y, the spacing can be reduced. Among the plurality of series antenna arrays 4 shown in FIG. 12, a part of the series antenna array 4 is used as a transmission antenna 40T, and the other series antenna array 4 is used as a reception antenna 40R. Thus, the antenna device 10 is provided as a MIMO (Multi Input Multi Output) antenna.

[0053] FIG. 13 is a diagram showing an example of reflection characteristics of the 41-stage patch array antenna (a type that supplies power to only one element in the center) of the first embodiment 3A. FIG. 14 is a diagram showing an example of reflection characteristics of the 41-stage patch array antenna (a type that supplies power to the same side of a plurality of elements in the same phase) of the third embodiment 3C. The horizontal axis represents frequency (MHz), and the vertical axis represents gain (dB). In the first embodiment 3A shown in FIG. 13, large resonance modes are observed at 23.5 GHz and 24.5 GHz besides 24 GHz, while in the third embodiment 3C shown in FIG. 14, unwanted resonance at 23.5 GHz and 24.5 GHz is suppressed. Thus, desired antenna characteristics can be obtained over a wide frequency range.

[0054] FIG. 15 is a diagram showing an example of reflection characteristics of the 41-stage patch array antenna (a type in which a plurality of elements is connected) of the fifth embodiment 3E. Even in the fifth embodiment 3E shown in FIG. 15, it can be seen that the unwanted resonance at 23.5 GHz and 24.5 GHz is suppressed. Thus, desired antenna characteristics can be obtained over a wide frequency range.

[0055] Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and it is of course possible for a person skilled in the art to make various changes.

[0056] Representative embodiments of the present invention will be listed below.

[0057] (1) An antenna device 10 comprising: a dielectric substrate 2; and a conductor pattern 3, 3A, 3B, 3C, 3D, 3E, or 3F formed on the dielectric substrate 2, comprising: a series antenna array 4 comprising: a plurality of patch antennas 41, 42, 43, 44, and 45 arranged in an alignment direction X1-X2, and a plurality of transmission lines 46, 47, 48, and 49, each of the plurality of transmission lines 46, 47, 48, and 49 connecting adjacent patch antennas of the plurality of patch antennas 41, 42, 43, 44, and 45; and an input / output line 5 configured to supply power to the series antenna array 4, the input / output line 5 connected to a side 421, 422, 431, 432, 441, or 442 extending in a width direction Y1-Y2, through which a transmission line 46, 47, 48, or 49, of the plurality of transmission lines 46, 47, 48, and 49, is connected to a patch antenna 42, 43, or 44 that is not one of patch antennas 41 or 45 at both ends of the series antenna array 4.

[0058] (2) The antenna device 10 according to (1), wherein the transmission line 46, 47, 48, or 49 is connected on one side deviated from a center in the width direction Y1-Y2 of the side 421, 422, 431, 432, 441, or 442 of the patch antenna 42, 43, or 44, and the input / output line 5 is connected to an opposite side deviated from the center in the width direction Y1-Y2 of the side 421, 422, 431, 432, 441, or 442 of the patch antenna 42, 43, or 44.

[0059] (3) The antenna device 10 according to (1) or (2), wherein the input / output line 5 comprises: a first line section 52 connected to one side 421 in one direction X1 of one patch antenna 42 of the series antenna array 4; and a second line section 53 connected to one side 441 in the same direction X1 of another patch antenna 44 of the series antenna array 4, wherein the first line section 52 and the second line section 53 either have same lengths or difference between respective lengths of the first line section 52 and the second line section 53 is an integer number multiple of a wavelength of a fundamental wave.

[0060] (4) The antenna device 10 according to (3), further comprises a connecting line 6 configured to connect: a side 422 of the one patch antenna 42 to which a transmission line 47, of the plurality of transmission lines 46, 47, 48, and 49, is connected, and a side 442 of the other patch antenna 44 to which another transmission line 49, of the plurality of transmission lines 46, 47, 48, and 49, is connected.

[0061] (5) The antenna device 10 according to (1) or (2), wherein the input / output line 5 includes: a first line section 52 connected to one side 421 in one direction X1 of one patch antenna 42 of the series antenna array 4, and a second line section 53 connected to one side 432 in an opposite direction X2 of another patch antenna 43 of the series antenna array 4, wherein the first line section 52 and the second line section 53 are set to respective lengths that causes a phase difference of half wavelength between fundamental waves input to the one patch antenna 42 and the other patch antenna 43.

[0062] (6) The antenna device 10 according to any of (1) to (5), wherein the input / output line 5 is disposed between sides 433 and 434 facing the width direction Y1-Y2 and extending in the alignment direction X1-X2 of a patch antenna 43 to which the input / output line 5 is connected.

[0063] (7) The antenna device 10 according to any of (1) to (6), wherein a width of the patch antenna 42, 43, or 44 to which the input / output line 5 is connected is wider than respective widths of the patch antennas 41 and 45 at both ends of the series antenna array 4.

[0064] (8) A transmitter 100 comprising the antenna device 10 according to any of (1) to (7).

[0065] (9) A radar 100 comprising the antenna device 10 according to any of (1) to (7).

[0066] It should be emphasized that many variations and modifications may be made to the above-described embodiments, the elements of which are to be understood as being among other acceptable examples. All such modifications and variations are intended to be included herein within the scope of this invention and protected by the following claims.

[0067] Patent Literature 1 - Chinese Patent Publication No. CN106972244BPatent Literature 2 - European Unexamined Patent Application Publication No. EP2950390A1

[0068] 100: Radar, 10: Antenna Device, 11: Transceiver, 12: Signal Processor, 13: Control Unit, 2: Dielectric Substrate, 3, 3A, 3B, 3C, 3D, 3E, and 3F: Conductor Patterns, 21: First Main Surface, 4: Series Antenna Array, 5: Input / Output Line, 40R: Reception antenna, 40T: Transmission antenna, 41, 42, 43, 44, and 45: Plurality of Patch Antennas, 46, 47, 48, and 49: Plurality of Transmission Lines, 46: First Transmission Line, 47: Second Transmission Line, 48: Third Transmission Line, 49: Fourth Transmission Line, X1-X2: Alignment Direction, Y1-Y2: Width Direction, 9: Feeding Point, 41 and 45: Patch Antennas at both ends of the Series Antenna Array, 43: Center Patch Antenna, 52 and 53: Plurality of Line Sections, 52: First Line Section, 53: Second Line Section, 51: Common Line Section, 6: Connecting Line, 421, 422, 431, 432, 441, and 442: Patch Antenna Sides in Width Direction, 433 and 434: Patch Antenna Sides in Alignment Direction

Claims

1. An antenna device (10) comprising: a dielectric substrate (2); and a conductor pattern (3, 3A, 3B, 3C, 3D, 3E, or 3F) formed on the dielectric substrate (2), comprising: a series antenna array (4) comprising: a plurality of patch antennas (41, 42, 43, 44, and 45) arranged in an alignment direction (X1-X2), and a plurality of transmission lines (46, 47, 48, and 49), each of the plurality of transmission lines (46, 47, 48, and 49) connecting adjacent patch antennas of the plurality of patch antennas (41, 42, 43, 44, and 45); and an input / output line (5) configured to supply power to the series antenna array (4), the input / output line (5) connected to a side (421, 422, 431, 432, 441, or 442) extending in a width direction (Y1-Y2), through which a transmission line (46, 47, 48, or 49), of the plurality of transmission lines (46, 47, 48, and 49), is connected to a patch antenna (42, 43, or 44) that is not one of patch antennas (41 or 45) at both ends of the series antenna array (4).

2. The antenna device (10) according to claim 1, wherein the transmission line (46, 47, 48, or 49) is connected on one side deviated from a center in the width direction (Y1-Y2) of the side (421, 422, 431, 432, 441, or 442) of the patch antenna (42, 43, or 44), and the input / output line (5) is connected to an opposite side deviated from the center in the width direction (Y1-Y2) of the side (421, 422, 431, 432, 441, or 442) of the patch antenna (42, 43, or 44).

3. The antenna device (10) according to claims 1 or 2, wherein the input / output line (5) comprises: a first line section (52) connected to one side (421) in one direction (X1) of one patch antenna (42) of the series antenna array (4); and a second line section (53) connected to one side (441) in the same direction (X1) of another patch antenna (44) of the series antenna array (4), wherein the first line section (52) and the second line section (53) either have same lengths or difference between respective lengths of the first line section (52) and the second line section (53) is an integer number multiple of a wavelength of a fundamental wave.

4. The antenna device (10) according to claim 3, further comprising: a connecting line (6) configured to connect: a side (422) of the one patch antenna (42) to which a transmission line (47), of the plurality of transmission lines (46, 47, 48, and 49), is connected, and a side (442) of the other patch antenna (44) to which another transmission line (49), of the plurality of transmission lines (46, 47, 48, and 49), is connected.

5. The antenna device (10) according to claims 1 or 2, wherein the input / output line (5) includes: a first line section (52) connected to one side (421) in one direction (X1) of one patch antenna (42) of the series antenna array (4), and a second line section (53) connected to one side (432) in an opposite direction (X2) of another patch antenna (43) of the series antenna array (4), wherein the first line section (52) and the second line section (53) are set to respective lengths that causes a phase difference of half wavelength between fundamental waves input to the one patch antenna (42) and the other patch antenna (43).

6. The antenna device (10) according to any of claims 1 to 5, wherein the input / output line (5) is disposed between sides (433 and 434) facing the width direction (Y1-Y2) and extending in the alignment direction (X1-X2) of a patch antenna (43) to which the input / output line (5) is connected.

7. The antenna device (10) according to any of claims 1 to 6, wherein a width of the patch antenna (42, 43, or 44) to which the input / output line (5) is connected is wider than respective widths of the patch antennas (41 and 45) at both ends of the series antenna array (4).

8. A transmitter (100) comprising the antenna device (10) according to any one of claims 1 to 7.

9. A radar (100) comprising the antenna device (10) according to any one of claims 1 to 7.

Images