Antenna substrate

Abstract

An antenna substrate, according to the present invention, comprises: a ground layer; a radiating patch layer disposed on top of the ground layer in a first direction and comprising a radiating patch which receives power through a plurality of main vias to radiate electromagnetic waves to the outside; a stacked-patch layer disposed on top of the radiating patch layer in the first direction and comprising a stack patch designed to have a resonance frequency different from that of the radiating patch to achieve multi-band performance; and an impedance matching unit disposed between the ground layer and the radiating patch layer to minimize signal reflection by adjusting impedance matching.

Description

antenna substrate

[0001] The present invention relates to an antenna substrate, and more particularly, to an antenna substrate including a stacked patch antenna that can achieve wideband, improve integrity, reduce EMI, and perform specific frequency filtering by adding a ground via and a via stub to induce frequency matching.

[0002] To realize the representative services of 6G, such as eXtended Reality (XR) and hologram services, wireless communication technology with ultra-low latency and ultra-wide bandwidth capable of microsecond-level latency and terabit per second (Tbps) data transmission is required. To provide users with related services using wireless communication technology with the above-mentioned ultra-low latency and ultra-wide bandwidth characteristics, interest in wireless communication technology utilizing the sub-terahertz (Sub-THz) frequency band is higher than ever. Sub-THz antennas operate in the 100 GHz to 1 THz band and are used in 6G communication, imaging systems, and high-resolution radar.

[0003] The shift from millimeter waves (mmWaves) to sub-terahertz is driven by the desire to leverage wider bandwidths, but it faces limitations due to the inherent characteristics of patch antennas. Specifically, frequency and physical length are inversely proportional, requiring sophisticated manufacturing techniques during fabrication.

[0004] The present invention aims to provide an antenna substrate including a stacked patch antenna capable of performing integrity enhancement, EMI reduction, and specific frequency filtering.

[0005] Another object of the present invention is to provide an antenna substrate including a stacked patch antenna usable in millimeter wave (mmWave) and sub-terahertz (Sub-THz) bands, wherein impedance matching and radiation characteristics can be adjusted by additionally utilizing a stub.

[0006] In order to achieve these objects, the antenna substrate according to the present invention is characterized in that it comprises a ground layer including a metal; a radiating patch layer disposed on the ground layer in a first direction and including a radiating patch that receives power through a plurality of main vias and radiates electromagnetic waves to the outside; a stack patch layer disposed on the radiating patch layer in the first direction and including a stack patch designed to have a different resonance frequency from the radiating patch to implement multi-band characteristics; and an impedance matching unit disposed between the ground layer and the radiating patch layer and including a resonance frequency adjusting unit that adjusts the resonance frequency for impedance matching.

[0007] In the antenna substrate according to the present invention, the resonant frequency adjusting unit may include a plurality of main stubs formed in adjacent areas of the plurality of main vias on a virtual plane perpendicular to the first direction; a plurality of auxiliary stubs arranged parallel to the plurality of main stubs on the virtual plane; and a plurality of auxiliary vias extending parallel to the plurality of main stubs in the first direction from the ground layer and connected to the plurality of auxiliary stubs.

[0008] In the antenna substrate according to the present invention, the radiating patch layer may include a radiating insulating layer disposed below the radiating patch and above the impedance matching insulating layer, the stack patch layer may include a stack insulating layer disposed below the stack patch and above the radiating patch, and the impedance matching unit may include an impedance matching insulating layer disposed between a plurality of main stubs and a plurality of auxiliary stubs and the ground layer.

[0009] In the antenna substrate according to the present invention, the main via is a signal via that transmits a signal to the radiating patch, and the auxiliary via is a ground via that connects to a ground layer to reduce EMI and perform impedance matching.

[0010] In the antenna substrate according to the present invention, the main via may include a first main via and a second main via, which are respectively connected to two feeding points of the radiating patch, which are arranged on two virtual lines perpendicular to each other on an imaginary plane from the center of the radiating patch, and the main stub may include two main stubs, which are arranged adjacent to the first main via and the second main via, respectively, and which extend by a predetermined length in a direction perpendicular to each other on the imaginary plane.

[0011] In the antenna substrate according to the present invention, the two main stubs may be formed in a rectangular shape of the same size.

[0012] In the antenna substrate according to the present invention, the auxiliary stub includes a first auxiliary stub having first and second sides facing each of the first side surfaces of the two main stubs and disposed on the same horizontal plane as the two main stubs; a second auxiliary stub having one side facing a side adjacent to one side of the first main stub facing the first side of the first auxiliary stub and disposed on the same horizontal plane as the first auxiliary stub; and a third auxiliary stub having one side facing a side adjacent to one side of the second main stub facing the second side of the first auxiliary stub and disposed on the same horizontal plane as the first auxiliary stub, and the auxiliary via includes a first auxiliary via extending in the first direction parallel to the first main via and the second main via between the first auxiliary stub and the ground layer; It may be formed by including a second auxiliary via extending in the first direction in parallel with the first main via and the second main via between the second auxiliary stub and the ground layer; and a third auxiliary via extending in the first direction in parallel with the first main via and the second main via between the third auxiliary stub and the ground layer.

[0013] In the antenna substrate according to the present invention, the distance between the first auxiliary via and the first main via may be the same as the distance between the first auxiliary via and the second main via.

[0014] In the antenna substrate according to the present invention, the distance between the second auxiliary via and the first main via may be the same as the distance between the third auxiliary via and the second main via.

[0015] In the antenna substrate according to the present invention, the separation distance between the second auxiliary stub and the first main stub may be shorter than the separation distance between the first main stub and the first auxiliary stub, and the separation distance between the third auxiliary stub and the second main stub may be shorter than the separation distance between the second main stub and the first auxiliary stub.

[0016] In the antenna substrate according to the present invention, the auxiliary stub may include the first auxiliary stub, the second auxiliary stub, and the third auxiliary stub, which are arranged in a straight line on the same horizontal plane.

[0017] In the antenna substrate according to the present invention, the second auxiliary stub and the third auxiliary stub may have a rectangular shape of the same size and may have the same size as the first main stub and the second main stub.

[0018] In the antenna substrate according to the present invention, the second auxiliary stub and the third auxiliary stub may have a rectangular shape of the same size and may have a smaller size than the first auxiliary stub.

[0019] In the antenna substrate according to the present invention, the radiation insulating layer, the stack insulating layer, and the impedance matching insulating layer may be formed of dielectric layers of the same material having the same thickness.

[0020] The antenna substrate according to the present invention can be expected to improve integrity and reduce EMI by adding a stub to a via to perform filtering and impedance correction at a specific frequency, and can adjust impedance matching and radiation characteristics in the millimeter wave (mmWave) and sub-terahertz (Sub-THz) bands.

[0021] FIG. 1 is an exemplary diagram showing an antenna substrate including a stack patch antenna according to the present invention.

[0022] Figure 2 is an example diagram showing part “A” of Figure 1 in more detail.

[0023] Figures 3a to 3c are exemplary diagrams showing changes in antenna characteristics when the antenna height is increased.

[0024] Figures 4a to 4c are exemplary diagrams showing changes in the characteristics of an antenna when a feed stub is added.

[0025] Figures 5a to 5c are exemplary diagrams showing changes in the characteristics of an antenna when a ground stub grounded through a ground via is added.

[0026] FIG. 6a and FIG. 6b are exemplary diagrams showing changes in the characteristics of an antenna when multiple ground stubs grounded through multiple ground vias are added.

[0027] With respect to the embodiments of the present invention disclosed in the text, specific structural and functional descriptions are merely exemplified for the purpose of explaining the embodiments of the present invention, and the embodiments of the present invention may be implemented in various forms and should not be construed as being limited to the embodiments described in the text.

[0028] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated in the drawings and described in detail herein. However, this is not intended to limit the present invention to specific disclosed forms, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0029] While terms like "first" and "second" may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component."

[0030] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but there may also be other components in between. Conversely, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Other expressions that describe the relationship between components, such as "between" and "directly between" or "adjacent to" and "directly adjacent to", should be interpreted similarly. Similarly, "disposed on" can mean disposed directly on the surface of another component or disposed above the surface by a distance.

[0031] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprises" or "has" indicate the presence of a disclosed feature, number, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0032] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant technology, and shall not be construed in an idealized or overly formal sense unless explicitly defined herein.

[0033] Meanwhile, if a particular embodiment can be implemented differently, the functions or operations specified within a particular block may occur in a different order than specified in the flowchart. For example, two consecutive blocks may actually be performed substantially simultaneously, or, depending on the related functions or operations, the blocks may be performed in reverse order.

[0034] Hereinafter, the configuration and operation of an antenna substrate including a stacked patch antenna according to the present invention will be described with reference to the attached drawings. For convenience, the antenna substrate will be described using a Cartesian coordinate system (x-axis, y-axis, z-axis), but it is obvious that it can also be described using other coordinate systems. In addition, according to the Cartesian coordinate system, the x-axis, y-axis, and z-axis are orthogonal to each other, but the embodiment is not limited thereto. That is, the x-axis, y-axis, and z-axis may intersect each other.

[0035] A sub-terahertz (Sub-THz) antenna is an antenna that operates in the 100 GHz to 1 THz band and is used in 6G communications, imaging systems, high-resolution radars, etc. An antenna substrate including a stacked patch antenna according to the present invention may include a 4-layer sub-terahertz (Sub-THz) antenna capable of transmitting and receiving wireless signals in a frequency band between 110 GHz and 140 GHz, having a structure in which multiple patches are stacked to expand bandwidth and improve radiation characteristics.

[0036] FIG. 1 is an exemplary diagram showing an antenna substrate including a stack patch antenna according to the present invention, and FIG. 2 is an exemplary diagram showing part “A” of FIG. 1 in more detail.

[0037] Here, the antenna substrate may mean a hybrid antenna substrate, an antenna in package (AIP), an antenna array substrate, or an antenna array.

[0038] The antenna substrate may include an antenna portion including an antenna and a routing portion. In one embodiment, the antenna portion may be disposed on the routing portion. In one embodiment, the antenna substrate may further include a core portion, and the antenna portion may be disposed on the core portion, and the routing portion may be disposed below the core portion. In one embodiment, the antenna portion and the routing portion may be disposed on the same horizontal plane. In one embodiment, the routing portion and the antenna portion may be disposed to be spaced apart from each other, and the routing portion and the antenna portion may be electrically connected to each other by a connecting member, such as a flexible printed circuit board (FPCB), a solder ball, or a metal bump.

[0039] Hereinafter, for convenience of explanation, the description will be made on the assumption that the antenna portion of the antenna substrate is positioned above the routing portion. However, it will be understood that the present disclosure can also be applied to cases where the antenna substrate has the structure of the above-described embodiments. In addition, the description will be made on the assumption that the antenna substrate includes the antenna portion and the routing portion. However, the antenna substrate may include only the antenna portion, and the routing portion may be formed as a separate component and connected to the antenna substrate.

[0040] The antenna substrate may include a plurality of wiring layers and a plurality of insulating layers that are stacked and spaced apart from each other in the vertical direction. In one embodiment, the antenna portion may include a plurality of first wiring layers and a plurality of first insulating layers. And the routing portion may include a plurality of second wiring layers arranged under the plurality of first wiring layers and a plurality of second insulating layers arranged under the plurality of first insulating layers.

[0041] Here, the wiring layer may include a radiating patch, a stub, a feed pad, a feed section, a ground, and a transmission line that constitute the antenna. The current supplied through the port may be supplied to the antenna section through the transmission line. In addition, the wiring layer may include a metal material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or an alloy thereof.

[0042] Here, each of the first insulating layer and the second insulating layer may include a thermosetting resin such as an epoxy resin, a thermoplastic resin such as a polyimide, or a material including a reinforcing material such as glass fiber and / or an inorganic filler together with these, for example, ABF, PID, BCC, or prepreg (PPG). In addition, each of the first insulating layer and the second insulating layer may include a glass plate or a ceramic plate.

[0043] The wiring layer included in the routing section may include signal patterns, power patterns, or resistance patterns. In addition, the routing section may have a combination of various routing characteristics, such as power / data, input / output, and RF (Radio Frequency) routing.

[0044] As shown, the stack patch antenna according to the present invention comprises a ground layer (100), an impedance matching portion (200), a radiating patch layer (300), and a stack patch layer (400) sequentially stacked in a first direction (vertical direction: z-axis direction).

[0045] The ground layer (100) of the stack patch antenna blocks electromagnetic waves entering each component of the antenna to maintain safety. The ground layer (100) may include metal.

[0046] The radiating patch layer (300) is arranged on the upper portion of the ground layer (100) in the first direction (z-axis direction). The radiating patch layer (300) includes a radiating patch (310) that receives power through a plurality of main vias (500) and radiates electromagnetic waves to the outside. The radiating patch layer (300) includes a radiating insulating layer (320) that is arranged between the lower portion of the radiating patch (310) and the impedance matching unit (200).

[0047] The stack patch layer (400) is disposed on top of the radiating patch layer (300) in the first direction (z-axis direction). The stack patch layer (400) includes a stack patch (410) that is designed to have a different resonance frequency from the radiating patch (310) to implement multi-band characteristics. The stack patch layer (400) includes a stack insulation layer (420) disposed between the lower portion of the stack patch (410) and the upper portion of the radiating patch (310).

[0048] The impedance matching unit (200) includes a resonance frequency adjusting unit (210) that is positioned between the ground layer (100) and the radiating patch layer (300) to adjust impedance matching and minimize signal reflection. The impedance matching unit (200) includes an impedance matching insulating layer (220) that is positioned between the resonance frequency adjusting unit (210) and the ground layer (100).

[0049] The above ground layer (100) includes a power supply structure necessary for the operation of the antenna, and the impedance matching insulating layer (220) can optimize impedance matching and radiation patterns by adjusting the thickness. The radiation insulating layer (320) includes a low-loss dielectric material, forms a resonant frequency, and can adjust phase velocity and propagation characteristics by optimizing the thickness. The stack insulating layer (420) functions as a protective layer, can improve patch radiation characteristics at high frequencies, and can prevent unnecessary loss by using an ultra-thin dielectric.

[0050] The resonance frequency control unit (210) includes a plurality of main vias (500), auxiliary vias (600), main stubs (710 and 720), and auxiliary stubs (810 to 830), as shown in an enlarged view in FIG. 2.

[0051] The main via (500) includes a first main via (510) and a second main via (520). Each main via (510, 520) is a conductive structure that is connected to a power supply structure through a through hole (TH1, TH2) formed in a ground layer (100) and transmits power and signals required for the operation of the radiating patch (310) of the radiating patch layer (300). Each main via (510, 520) is a signal via that transmits a signal to the radiating patch (310). Each main via (510, 520) is connected to two feeding points (P1, P2) of the radiating patch (300) respectively, which are arranged on two virtual lines (x', y') that are perpendicular to each other in the second direction (x-axis direction) and the third direction (y-axis direction) perpendicular to the first direction (z-axis direction: vertical direction) from the center of the radiating patch (310).

[0052] The main stub (710, 720) includes a first main stub (710) and a second main stub (720). The first main stub (710) is connected to the first main via (510), and the second main stub (720) is connected to the second main via (520). The first main stub (710) and the second main stub (720) may be short transmission lines that induce resonance at a specific frequency and may also filter signals of a specific frequency by reflecting or absorbing them. The first main stub (710) surrounds the first main via (510) and extends in the third direction (y-axis direction). The second main stub (720) surrounds the second main via (520) and extends in the second direction (x-axis direction). That is, the first main stub (710) and the second main stub (720) extend in directions perpendicular to each other while surrounding the first main via (510) and the second main via (520), respectively. The plurality of main stubs (710, 720) may have the same thickness. The plurality of main stubs (710, 720) may have the same length. The plurality of main stubs (710, 720) may have the same shape. The plurality of main stubs (710, 720) may be formed in the shape of rectangles of the same size. This is according to one embodiment and may be changed according to frequency characteristics.

[0053] A plurality of auxiliary stubs (810, 820, 830) are arranged parallel to the plurality of main stubs (710, 720) on the plane of the impedance matching insulating layer (220).

[0054] The first auxiliary stub (810) is arranged at a portion where the virtual extension lines of the first main stub (710) and the second main stub (720) intersect. The first side (811) of the first auxiliary stub (810) faces the second side (712) of the first main stub (710) and is spaced apart from the second side (712) by a first distance (d1). The first side (811) of the first auxiliary stub (810) and the second side (712) of the first main stub (710) may overlap at least partially in the third direction (y-axis direction). The first side (811) of the first auxiliary stub (810) may have the same size (length and thickness) as the second side (712) of the first main stub (710). The second face (812) of the first auxiliary stub (810) faces the first face (721) of the second main stub (720) and is spaced apart from the first face (721) by a second distance (d2). The second face (812) of the first auxiliary stub (810) and the first face (721) of the second main stub (720) may overlap at least partially in the second direction (x-axis direction). The second face (812) of the first auxiliary stub (810) may have the same size (length and thickness) as the first face (721) of the second main stub (720). The length (L3) of the opposite side of the first side (811) of the first auxiliary stub (810) is longer than the length of the first side (811), and the length (L4) of the opposite side of the second side (812) of the first auxiliary stub (810) is longer than the length of the second side (812).

[0055] The second auxiliary stub (820) is arranged to be spaced apart from the first main stub (710) by a predetermined distance in the second direction (x-axis direction). The first face (821) of the second auxiliary stub (820) faces the first face (711) of the first main stub (710) and is spaced apart from the first face (711) by a third distance (d3). The first face (821) of the second auxiliary stub (820) and the first face (711) of the first main stub (710) may overlap at least partially in the second direction (x-axis direction). The first face (821) of the second auxiliary stub (820) may have the same size as the first face (711) of the first main stub (710). The length (L5) of the second auxiliary stub (820) may be the same as the length (L1) of the third auxiliary stub (830). This is one embodiment, and if the length is changed, the resonant frequency may change.

[0056] The third auxiliary stub (830) is arranged at a predetermined distance in the third direction (y-axis direction) from the second main stub (720). The first side (831) of the third auxiliary stub (830) faces the second side (722) of the second main stub (720) and is spaced at a fourth distance (d4). The first side (831) of the third auxiliary stub (830) and the second side (722) of the second main stub (720) may overlap at least partially in the third direction (y-axis direction). The width (W1) of the first side (831) of the third auxiliary stub (830) may have the same size as the width (W2) of the first side (721) of the second main stub (720). The length (L1) of the third auxiliary stub (830) may have the same size as the length (L2) of the second main stub (720). This is one embodiment, and if the length is changed, the resonant frequency may change.

[0057] The second auxiliary stub (820) and the third auxiliary stub (830) may have the same length, width, and thickness. The second auxiliary stub (820) and the third auxiliary stub (830) may have a rectangular shape of the same size.

[0058] The auxiliary via (600) includes a first auxiliary via (610), a second auxiliary via (620), and a third auxiliary via (630). The first auxiliary via (610) is positioned between the first auxiliary stub (810) and the ground layer (100). The second auxiliary via (620) is positioned between the second auxiliary stub (820) and the ground layer (100). The third auxiliary via (630) is positioned between the third auxiliary stub (830) and the ground layer (100). In transmission of a high-frequency signal, the lengths of the first auxiliary via (610), the second auxiliary via (620), and the third auxiliary via (630) may cause resonance at a specific frequency.

[0059] The first main via (510) and the second main via (520), the first auxiliary via (610), the second auxiliary via (620), and the third auxiliary via (630), the first main stub (710) and the second main stub (720), the first auxiliary stub (810), the second auxiliary stub (820), and the third auxiliary stub (830) are all made of a conductive material and can have mutual inductance that can generate an induced electromotive force by affecting another conductor according to a change in current of one conductor. Capacitance is generated by an electric field that occurs between the first side (821) of the second auxiliary stub (820) and the first side (711) of the first main stub (710), between the second side (712) of the first main stub (710) and the first side (811) of the first auxiliary stub (810), between the second side (812) of the first auxiliary stub (810) and the first side (721) of the second main stub (720), and between the second side (722) of the second main stub (720) and the first side (831) of the third auxiliary stub (830).

[0060] The second auxiliary stub (820), the first auxiliary stub (810), and the third auxiliary stub (830) may be arranged on a virtual same line. The first main stub (710) and the second main stub (720) may be arranged on another virtual same line. The second auxiliary stub (820), the first auxiliary stub (810), and the third auxiliary stub (830) may be arranged on two virtual lines parallel to the first main stub (710) and the second main stub (720).

[0061] In this embodiment, the distance (d1) between the first main stub (710) and the first auxiliary stub (810), the distance (d2) between the first auxiliary stub (810) and the second main stub (720), the distance (d3) between the second auxiliary stub (820) and the first main stub (710), and the distance (d4) between the second main stub (720) and the third auxiliary stub (830) are all the same.

[0062] In another embodiment, the separation distance (d3) between the second auxiliary stub (820) and the first main stub (710) may be shorter or longer than the separation distance (d1) between the first main stub (710) and the first auxiliary stub (810). The separation distance (d4) between the third auxiliary stub (830) and the second main stub (720) may be shorter or longer than the separation distance (d2) between the second main stub (720) and the first auxiliary stub (810).

[0063] In another embodiment, the length (L5) of the second auxiliary stub (820) and the length (L1) of the third auxiliary stub (830) are equal, and may be longer or shorter than the lengths (L2) of the first main stub (710) and the second main stub (720).

[0064] The resonant frequency can be shifted or removed according to the separation distance (d1 to d4) between each stub to minimize signal reflection. The function of inducing resonance at a specific frequency and blocking and filtering signals in the corresponding band can be implemented according to the change in inductance and capacitance of each stub. The power transfer efficiency of the stacked patch antenna can be optimized by appropriately designing the length of each stub. In particular, by the role of the auxiliary vias (610, 620, 630) as ground vias, each stub can suppress noise in a specific frequency band, thereby reducing EMI emissions, thereby minimizing electromagnetic interference.

[0065] FIGS. 3A to 3C are exemplary diagrams showing changes in antenna characteristics when the antenna height is increased. Each antenna illustrated in FIGS. 3A and 3B represents a patch of the same size (576 X 576 ㎛) and the same thickness (15 ㎛) connected to a ground substrate (ground) with a thickness (15 ㎛). At this time, when the length of the first via is 100 ㎛, when the height of the antenna is increased to expand the bandwidth and the length of the second via is 150 ㎛, the impedance trajectory rotates clockwise as shown in the Smith chart of FIG. 3C, resulting in an effect of circles converging. However, if the length of the second via is too long and the distance between the patch and the ground substrate is too far, the phenomenon of mismatching may occur by deviating from the origin.

[0066] Figures 4a to 4c are exemplary diagrams showing changes in antenna characteristics when a feed stub is added. When a feed stub is connected to a via between a ground substrate (Ground) and a drive patch as shown in Figure 4a in a stack patch antenna in which a stack patch is stacked on top of a drive patch, the antenna impedance trajectory exhibits a characteristic of crossing over once with 116 GHz as a turning point, as shown in the reflection coefficient graph of Figure 4b and the Smith chart of Figure 4c. It can be seen that the trajectory moves clockwise due to the parasitic capacitor effect between the inductance of the feed stub itself and the ground, and at the same time, the high-frequency point moves more significantly.

[0067] Figures 5a to 5c are exemplary diagrams showing changes in the characteristics of an antenna when a ground stub is added through a ground via. As shown in Figure 5a, when a ground stub (GND stub) is placed on the same plane as a feed stub and connected to a ground substrate (Ground) through a ground via, as shown in the reflection coefficient graph of Figure 5b and the Smith chart of Figure 5c, the effect of the shunt circuit by the ground via placed in parallel to the patch via causes a large impedance change at high frequencies, while the impedance change at low frequencies is small. Therefore, a larger impedance change occurs at high frequencies, inducing an additional resonance mode.

[0068] Figures 6a and 6b are exemplary diagrams showing changes in the characteristics of an antenna when a plurality of ground stubs grounded through a plurality of ground vias are added. Figure 6a shows a configuration in which a plurality of ground stubs (GND stubs) are arranged on the same plane as a plurality of feed stubs, as in a stacked patch antenna according to the present invention, and each of the ground stubs (GND stubs) is grounded using a plurality of ground vias (GND vias). There was a limitation in matching low-frequency impedances using only a shunt circuit. That is, as shown in the reflection coefficient illustrated in Fig. 6b, in the case of a general 4-layer stack patch antenna (dotted line), the minimum frequency of -10 dB bandwidth was 120 GHz, and the maximum frequency was 133 GHz, but in the case of a stack patch antenna (dotted line) in which ground vias (610, 620, 630) with auxiliary stubs (810, 820, 830) are arranged as in the present invention, the minimum frequency is 115 GHz, and the maximum frequency is 136 GHz. Compared to the case without a ground stub and a ground via, the impedance bandwidth can be increased by controlling the impedance matching and the resonant frequency, and the sensitivity can be improved by removing unnecessary signal reflections at high frequencies.

[0069] As described above, the stack patch antenna according to the present invention can adjust impedance matching and radiation characteristics in the millimeter wave (mmWave) and sub-terahertz (Sub-THz) bands by adding a stub to the via.

[0070] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

[0071] The mode for carrying out the invention has been sufficiently described in the above-mentioned “Best mode for carrying out the invention.”

[0072] The antenna substrate of the embodiment can be used in the field of wireless communication technology, etc.

Claims

1. Ground layer containing metal; A radiating patch layer disposed on the upper side of the ground layer in the first direction, and having a radiating patch that receives power through a plurality of main vias and radiates electromagnetic waves to the outside; A stack patch layer having a stack patch disposed on top of the radiating patch layer in the first direction and designed to have a resonant frequency different from that of the radiating patch to implement multi-band characteristics; and An antenna substrate including an impedance matching unit, which is disposed between the ground layer and the radiating patch layer and has a resonance frequency adjusting unit that adjusts the resonance frequency for impedance matching.

2. In the first paragraph, the resonance frequency control unit, A plurality of main stubs formed in adjacent areas of the plurality of main vias in a virtual plane perpendicular to the first direction; A plurality of auxiliary stubs arranged parallel to the plurality of main stubs on the virtual plane; and An antenna substrate including a plurality of auxiliary vias extending parallel to the plurality of main stubs in the first direction from the ground layer and connected to the plurality of auxiliary stubs.

3. In paragraph 2, The above radiation patch layer includes a radiation insulating layer disposed between the lower portion of the radiation patch and the upper portion of the impedance matching portion, The stack patch layer includes a stack insulation layer disposed between the lower portion of the stack patch and the upper portion of the radiating patch, An antenna substrate including an impedance matching insulating layer disposed between the plurality of main stubs and the plurality of auxiliary stubs and the ground layer, wherein the impedance matching portion is a ground layer.

4. In paragraph 2, The above multiple main vias are signal vias that transmit signals, The above multiple auxiliary vias are ground vias that connect to the ground layer and serve as EMI reduction and impedance matching antenna substrates.

5. In paragraph 4, The above plurality of main vias include a first main via and a second main via, each connected to two feeding points of the radiating patch, which are arranged on two virtual lines perpendicular to each other on the virtual plane at the center of the radiating patch, An antenna substrate including a first main stub and a second main stub, wherein the plurality of main stubs are arranged adjacent to the first main via and the second main via, respectively, and extend a predetermined length in a direction perpendicular to each other on the virtual plane.

6. In the fifth paragraph, the antenna substrate is formed with a rectangular shape of the same size as the first main stub and the second main stub.

7. In paragraph 6, The above multiple auxiliary stubs, A first auxiliary stub having first and second sides facing each other with respect to one side of the first main stub and the second main stub, and arranged on the same horizontal plane as the first and second main stubs; A second auxiliary stub having one side facing a side adjacent to one side of the first main stub facing the first side of the first auxiliary stub and arranged on the same horizontal plane as the first auxiliary stub; and A third auxiliary stub is disposed on the same horizontal plane as the first auxiliary stub, having one side facing a side adjacent to one side of the second main stub facing the second side of the first auxiliary stub, The above multiple auxiliary vias are, A first auxiliary via extending in the first direction parallel to the first main via and the second main via between the first auxiliary stub and the ground layer; a second auxiliary via extending in the first direction parallel to the first main via and the second main via between the second auxiliary stub and the ground layer; and An antenna substrate including a third auxiliary via extending in the first direction parallel to the first main via and the second main via between the third auxiliary stub and the ground layer.

8. An antenna substrate in accordance with claim 7, wherein the spacing between the first auxiliary via and the first main via is the same as the spacing between the first auxiliary via and the second main via.

9. An antenna substrate in accordance with claim 8, wherein the distance between the second auxiliary via and the first main via is the same as the distance between the third auxiliary via and the second main via.

10. In the 7th paragraph, the plurality of auxiliary stubs are an antenna substrate including the first auxiliary stub, the second auxiliary stub, and the third auxiliary stub, which are arranged in a straight line on the same horizontal plane.

Images