Probe-fed circularly-polarized stacked center-slotted patch antenna

Abstract

This document describes a stacked patch antenna, a stacked patch antenna array, and a method for manufacturing a stacked patch antenna. The stacked patch antenna includes a ground plane, a first substrate on the ground plane, a first patch on the first substrate having a first diagonal non-radiating center slot from one side of the first patch, a second substrate on the first patch, a second patch on the second substrate having a second diagonal non-radiating center slot from one side of the second patch similar to that side of the first patch, and a feed connector having a first conductor directly connected to the ground plane and a second conductor capacitively connected to the first patch and directly connected to the second patch.

Description

Technical Field

[0001] This invention relates to a probe-fed circularly polarized stacked center slot patch antenna. Government Interest Statement

[0002] This invention was completed with the support of the U.S. government, under contract number N00030-19-C-0025. The government holds certain rights to this invention. Prior Technology

[0003] Traditional corner-trimmed patch antennas have narrow bandwidth and high inter-component coupling, which degrades antenna performance (e.g., reduced gain and reduced phase dispersion characteristics). Summary of the Invention

[0004] Based on the concepts described herein, the example circularly polarized stacked center slot patch antenna device and method provide an antenna with a single feed circuit.

[0005] Based on the concepts described herein, the example circularly polarized stacked center slot patch antenna apparatus and method provide dual-band, tri-band, or higher frequency band antennas with a single feed circuit and multiple stacked patch antenna elements. Simple Explanation of the Diagram

[0006] The manner and process of manufacturing and using the disclosed embodiments can be understood by referring to the accompanying drawings. It should be understood that the parts and structures shown in the drawings are not necessarily drawn to scale, but are intended to emphasize the principles of the concepts described herein. Similar element symbols represent corresponding parts in different views. Furthermore, the embodiments are shown in the drawings by way of example rather than limitation, wherein:

[0007] [Figure 1A] is a schematic diagram of an example embodiment of a dual-band circularly polarized stacked center slot patch antenna;

[0008] [Figure 1B] is a partial perspective view of Figure 1A, showing the bottom patch of a dual-band circularly polarized stacked center slot patch antenna without a top patch;

[0009] [Figure 2] is a schematic diagram of an example embodiment of a dual-band circularly polarized stacked center slot patch antenna with offset impedance tuning;

[0010] [Figure 3A] is a schematic diagram of an example embodiment of a top view of an array of dual-band circularly polarized stacked center slot patch antennas;

[0011] [Figure 3B] is a schematic diagram of an example embodiment of the side view of the array of dual-band circularly polarized stacked center slot patch antennas shown in Figure 3A; and

[0012] [Figure 4] is a flowchart of an example method for constructing a dual-band circularly polarized stacked center slot patch antenna. Implementation

[0013] This disclosure provides an exemplary circularly polarized stacked center slot patch antenna with a single feed circuit. The antenna (e.g., a Global Positioning System (GPS) antenna) can be a dual-band, tri-band, or higher frequency band antenna having a single feed circuit and multiple stacked patch antenna elements.

[0014] Figure 1A is a schematic diagram of an example embodiment of a stacked patch antenna 100. In the example embodiment, the stacked patch antenna 100 includes a ground plane 101, a first substrate 103, a first patch 105, a second substrate 107, a second patch 109, and a feed connector 113. Therefore, the stacked patch antenna 100 includes a dual-band circularly polarized stacked center-slot patch antenna with a single feed circuit (e.g., for the L1 and L2 bands of GPS at 1.57542 GHz and 1.2276 GHz, respectively). However, this disclosure is not limited thereto. In the example embodiment, the stacked patch antenna 100 may include more than two patches.

[0015] Ground plane 101 is made of a conductive material (e.g., metal, copper, etc.). Ground plane 101 is shown in FIG. 1A as 4 inches long and 4 inches wide. However, this disclosure is not limited thereto. Ground plane 101 can be of any size. In an example embodiment, ground plane 101 may be connected to the outer conductor or shield of the coaxial connector used by power connector 113, as shown in FIG. 2 and described in more detail below, wherein the center conductor of the coaxial conductor may be used to provide radio frequency (RF) power to the first patch 105.

[0016] The first substrate 103 is an insulating material (e.g., ceramic) on the ground plane 101. In an example embodiment, the first substrate 103 may be an isotropic thermosetting microwave material (i.e., a ceramic-thermosetting polymer composite), such as Rogers Corporation's TMM® 10i laminate. The first substrate 103 is shown in FIG. 1A as 2 inches long, 2 inches wide, and 0.2 inches high (e.g., a small form factor, which is advantageous for antenna arrays). However, this disclosure is not limited thereto. The first substrate 103 may be of any size.

[0017] The first patch 105 is a conductive material (e.g., metal, copper, etc.) on the first substrate 103. In an example embodiment, the first patch 105 can be rectangular, square, or any shape within the size range of the first substrate 103. In the example, the first patch 105 (e.g., the lower patch) may not be directly connected to the power connector 113 (e.g., when the power connector 113 is a coaxial connector, the first patch 105 may not be directly connected to the center pin of the power connector 113), but may be capacitively coupled to the power connector 113 to receive radio frequency energy, by having gaps in the first patch 105 to allow electromagnetic coupling of radio frequency energy from the power connector 113 to the first patch 105. In the example, only the second patch 109 can be directly connected to the power connector 113 (e.g., the second patch 109 can be soldered to the power connector 113). In an example embodiment, the first patch 105 may be connected to the center connector or pin of a coaxial connector serving as a power supply connector 113, as shown in FIG2 and described in more detail below, wherein the center conductor of the coaxial conductor serving as the power supply connector 113 provides RF power to the first patch 105. In an example embodiment, the first patch 105 may include a first diagonal non-radiating center slot 115, as shown in FIG1B and described in more detail below. In an example embodiment, the first diagonal non-radiating center slot 115 may be oriented at approximately 45 degrees from one side of the first patch 105 and may be rotated to independently change the orthogonal polarization component. Center slots on patches may be less susceptible to inter-component coupling because edge field perturbations may be smaller when placed close to each other in an array configuration. Probe feeding provides low cost and low complexity. In the example, more than two patches may be used, with the power supply connector directly connected to the topmost patch and capacitively coupled to other (e.g., lower) patches.

[0018] The second substrate 107 is an insulating material (e.g., ceramic) on the first patch 105 and the first substrate 103. In an example embodiment, the second substrate 107 may be an isotropic thermosetting microwave material (i.e., a ceramic-thermosetting polymer composite), such as Rogers Corporation's TMM® 10i laminate. The second substrate 107, shown in FIG. 1A, is 2 inches long, 2 inches wide, and 0.2 inches high, and its dimensions are the same as those of the first substrate 103. However, this disclosure is not limited thereto. The second substrate 107 may be of any size.

[0019] The second patch 109 is a conductive material (e.g., metal, copper, etc.) on the second substrate 107. In an example embodiment, the second patch 109 can be rectangular, square, or any shape within the size range of the second substrate 107. In an example embodiment, the second patch 109 can be directly connected to the center connector or pin of a coaxial connector used as a power supply connector 113, as shown in FIG2 and described in more detail below, wherein the center conductor of the coaxial conductor used as the power supply connector 113 provides RF power to the second patch 109. A single power supply connector 113 excites the first patch 105 and the second patch 109 respectively, simplifying the manufacturing process. In an example embodiment, the second patch 109 may include a second diagonal non-radiating center slot 111.

[0020] In an example embodiment, the second diagonal nonradiative center slot 111 can be oriented at approximately 45 degrees and can be rotated to independently change the orthogonal polarization components. In an example embodiment, the second diagonal nonradiative center slot 111 on the second patch 109 can be oriented in the same way as the first diagonal nonradiative center slot 115 on the first patch 105, enabling right-hand circular polarization (RHCP). In an example embodiment, the second diagonal nonradiative center slot 111 on the second patch 109 can be oriented in the opposite way to the first diagonal nonradiative center slot 115 on the first patch 105, enabling left-hand circular polarization (LHCP). The nonradiative diagonal center slots can enable a phase delay of the current, thereby exciting two orthogonally polarized electric fields. The diagonal center slot is a tuning feature that does not disturb the electric field at the edges of the stacked patch antenna 100, allowing the stacked patch antenna 100 to be more closely spaced in a controlled receive mode antenna (CRPA) array configuration, as shown in Figure 3 and described in more detail below.

[0021] In an example embodiment, the second patch 109 (e.g., the upper or top patch) may be offset from the first patch 105 (e.g., the lower or bottom patch) in a "skip" configuration to provide additional tuning features for upper band antenna impedance matching, as shown in FIG2 and described in more detail below.

[0022] In an example embodiment, the power supply connector 113 may be a coaxial connector or a pin, wherein the outer conductor of the coaxial connector may be directly connected to the ground plane 101, and the center connector of the coaxial connector may be capacitively coupled to the first patch 105 through the gap present in the first patch 105 around the power supply connector 113, but not directly connected to the first patch 105, to provide RF power to the first patch 105, as shown in FIG2 and described in more detail below.

[0023] The stacked patch antenna 100 exhibits reduced coupling, improving antenna performance compared to the corner-trimmed patch antenna. Therefore, the stacked patch antenna 100 demonstrates better gain and phase dispersion characteristics, which is beneficial for anti-interference algorithms and null control.

[0024] Compared to corner-trimmed or rectangular circularly polarized stacked patch antennas, the circular polarization in the stacked patch antenna 100 is less susceptible to interference from coupling from adjacent patch antenna elements. Therefore, the stacked patch antenna 100 can exhibit improved gain and phase flatness, particularly at the waterline.

[0025] Figure 1B is a partial perspective view of Figure 1A, showing the first patch 105 of the stacked patch antenna 100 of Figure 1A, but not the second patch 109. In an example embodiment, the first patch 105 may be located on a first substrate 103, which may be located on a ground plane 101. A feed connector 113 (e.g., a coaxial connector) may be capacitively coupled through gaps in the first patch 105 surrounding the feed connector 113, but not directly connected to the first patch 105 through the center conductor of the feed connector 113, wherein the outer conductor of the feed connector 113 may be directly connected to the ground plane 101. In an example embodiment, the first patch 105 includes a first diagonal non-radiating center slot 115, as described in more detail above.

[0026] Figure 2 is a schematic diagram of an example embodiment of a stacked patch antenna 100 with offset impedance tuning. In the example embodiment, a first substrate 103 has a first patch 105 thereon. A second substrate 107 is on the first patch 105 and overlaps with the first substrate 103. A second patch 109 is located on the second substrate 107 and overlaps with and is offset from the first patch 105 in a "skip" configuration to provide additional tuning features for impedance matching in the upper frequency band of the stacked patch antenna 100. Since the first diagonal non-radiating center slot 115 and the second diagonal non-radiating center slot 111 are non-radiating, they do not need to be oriented relative to each other, but can be used as independent tuning features in terms of RHCP or LHCP purity. The first diagonal non-radiating center slot 115 and the second diagonal non-radiating center slot 111 can be oriented at approximately 45 degrees relative to the square / rectangular patch. The angle can be varied to slightly improve circular polarization performance. The jumper configuration between the first patch 105 and the second patch 109 allows each patch to be properly impedance matched without any additional matching circuitry or board layers. Patches (e.g., those not in direct contact with the first patch 105, but through gaps in the first patch 105 surrounding the power connector 113) to the power connector 113 can have a circular diameter (e.g., the capacitive coupling region between the first patch 105 and the power connector 113) that serves as an additional impedance matching mechanism.

[0027] In an example embodiment, the power supply connector 113 includes a coaxial connector having an outer conductor directly connected to the ground plane 101 and a capacitively coupled center conductor (e.g., through a gap in the first patch 105 around the power supply connector 113), but not directly connected to the first patch 105 but directly connected to the second patch 109 to provide radio frequency power to the first patch 105 and the second patch 109.

[0028] In an example embodiment, the first patch 105 includes a first diagonal non-radiative central slot 115, and the second patch 109 includes a second diagonal non-radiative central slot 111, as described in more detail above. FIG2 shows that the first diagonal non-radiative central slot 115 and the second diagonal non-radiative central slot 111 have similar orientations. However, this disclosure is not limited thereto. In an example embodiment, the first diagonal non-radiative central slot 115 and the second diagonal non-radiative central slot 111 may have opposite orientations, as described in more detail above.

[0029] Figure 3A is a schematic diagram of an example embodiment of an array 300 of stacked patch antennas 303, 305, 307, 309, and 311, viewed from a top view. In the example embodiment, each of the stacked patch antennas 303, 305, 307, 309, and 311 may be the same as the stacked patch antenna 100 of Figure 1A, and as described above in more detail.

[0030] Figure 3A shows an array of five stacked patch antennas 303, 305, 307, 309, and 311 arranged in a circular pattern on a substrate 301 with a radius of 6.44 inches. The spacing between the stacked patch antennas 303, 305, 307, 309, and 311 is 3.175 inches, and the patch radius between adjacent stacked patch antennas 303, 305, 307, 309, and 311 is the spacing between adjacent stacked patch antennas 303, 305, 307, 309, and 311 (e.g., spacing of 2.85 inches, 3.75 inches, 4.75 inches, etc.) divided by 2 sin 36 degrees. However, this disclosure is not limited to this. Other numbers of stacked patch antennas 101 may be arranged with different spacing and different patch radii.

[0031] In the example embodiment, the substrate 301 may be a metal (e.g., aluminum (Al) for low temperatures, titanium (Ti) for high temperatures, etc.).

[0032] Figure 3B is an array side view of the five stacked patch antennas 303, 305, 307, 309 and 311 in Figure 3A.

[0033] Figure 4 is a flowchart of an example method 400 for manufacturing a stacked patch antenna, which includes depositing a ground plane in step 401.

[0034] Step 403 of method 400 includes forming a first substrate on a ground plane. Step 405 of method 400 includes forming a first patch on the first substrate having a first diagonal non-radiating center slot. Step 407 of method 400 includes forming a second substrate on the first patch. Step 409 of method 400 includes forming a second patch on the second substrate having a second diagonal non-radiating center slot. Step 411 of method 400 includes forming a power supply connector having a first conductor directly connected to the ground plane and a second conductor capacitively conductively connected but not directly connected to the first patch and directly connected to the second patch.

[0035] Having described the disclosed exemplary embodiments, it will now be apparent to those skilled in the art that other embodiments incorporated therein may also be used. The embodiments contained herein should not be limited to the disclosed embodiments, but should be limited only by the spirit and scope of the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety.

[0036] Elements from the different embodiments described herein can be combined to form other embodiments not specifically described above. Various elements described in the context of a single embodiment may also be provided individually or in any suitable sub-combination. Other embodiments not specifically described herein are also within the scope of the appended claims.

[0037] This document describes various embodiments of the concepts, systems, devices, structures, and techniques for which protection is sought, with reference to the relevant figures. Alternative embodiments may be designed without departing from the scope of the concepts, systems, devices, structures, and techniques described herein.

[0038] It should be noted that the above descriptions and diagrams illustrate various connections and positional relationships between elements (e.g., above, below, adjacent, etc.). Unless otherwise stated, these connections and / or positional relationships can be direct or indirect, and the concepts, systems, devices, structures, and techniques described are not intended to be limited to this pattern. Therefore, coupling of entities can refer to direct or indirect coupling, and positional relationships between entities can be direct or indirect positional relationships.

[0039] As an example of an indirect positional relationship, the reference in this specification to forming layer "A" on top of layer "B" includes cases where one or more intermediate layers (e.g., layer "C") are located between layer "A" and layer "B," provided that the relevant characteristics and functions of layer "A" and layer "B" are not significantly altered by the intermediate layers. The following definitions and abbreviations are used to interpret the scope of the claims and the specification. As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," "contains," or "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, mixture, process, method, article, or apparatus that includes a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such compositions, mixtures, processes, methods, articles, or apparatus.

[0040] Additionally, the term "exemplary" is used herein to mean as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" is not necessarily to be construed as superior or advantageous to other embodiments or designs. The terms "one or more" and "one or more" should be understood to include any integer greater than or equal to one, i.e., one, two, three, four, etc. The term "multiple" should be understood to include any integer greater than or equal to two, i.e., two, three, four, five, etc. The term "connection" can include both indirect and direct "connections".

[0041] References to "an embodiment," "an embodiment," "an exemplary embodiment," etc., in this specification indicate that the described embodiment may include specific features, structures, or characteristics, but each embodiment may include specific features, structures, or characteristics. Furthermore, such terminology does not necessarily refer to the same embodiment. Additionally, when a specific feature, structure, or characteristic is described in connection with an embodiment, it is believed that its influence on that feature, structure, or characteristic in relation to other embodiments is within the knowledge of those skilled in the art, whether explicitly described or not.

[0042] For the purposes described herein, terms such as “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” and others (to name only a few) and their derivatives shall apply to the structures and methods described, oriented as shown in the figures in the schemata. The terms “overlapping,” “atop,” “on top,” “positioned on,” or “positioned on top” indicate that a first element (e.g., a first structure) is present on a second element (e.g., a second structure), wherein an intermediate element (e.g., an interface structure) may be present between the first and second elements. The term “direct contact” means that the first element (e.g., the first structure) and the second element (e.g., the second structure) are connected without any intermediate element. Such terms are sometimes referred to as directional or positional terms.

[0043] Using ordinal terms (e.g., "first", "second", "third", etc.) in a request item to modify the request item element itself does not imply any priority, precedence, or order of one request item element relative to another request item element, nor does it imply the temporal order of the execution of method actions. Rather, it is used only as a label to distinguish one request item element with a specific name from another element with the same name (but using ordinal terms) to differentiate request item elements.

[0044] The terms "approximately" and "about" can be used to indicate that in some embodiments the value is within ±20% of the target value, in some embodiments it is within ±10% of the target value, in some embodiments it is within ±5% of the target value, and in some embodiments it is still within ±2% of the target value. The terms "approximately" and "about" can include the target value. The term "substantially equal" can be used to indicate that in some embodiments the error values ​​are within ±20% of each other, in some embodiments within ±10%, in some embodiments within ±5%, and in some embodiments it is still within ±2%.

[0045] The term "substantially" can be used to refer to a value within ±20% in some embodiments, within ±10% in some embodiments, within ±5% in some embodiments, and still within ±2% in some embodiments. For example, "substantially" perpendicular to the second direction can mean that the first direction is within ±20% of the second direction at a 90° angle in some embodiments, within ±10% of the second direction at a 90° angle in some embodiments, within ±5% of the second direction at a 90° angle in some embodiments, and still within ±2% of the second direction at a 90° angle in some embodiments.

[0046] It should be understood that the disclosed subject matter is not limited in its application to the details of the structure and the arrangement of components set forth in the following description or shown in the figures. The disclosed subject matter can have other embodiments and can be practiced and implemented in various ways.

[0047] Furthermore, it should be understood that the words and terms used herein are for descriptive purposes and should not be considered limiting. Therefore, those skilled in the art will understand that the concepts upon which this disclosure is based can be readily used as the basis for designing other structures, methods, and systems to achieve multiple purposes of the disclosed subject matter. Therefore, claims should be considered to include such equivalent constructions, provided they do not depart from the spirit and scope of the disclosed subject matter.

[0048] Although the disclosed subject matter has been described and illustrated in the exemplary embodiments described above, it should be understood that this disclosure is by way of example only, and many modifications may be made to the implementation details of the disclosed subject matter without departing from the spirit and scope of the disclosed subject matter.

[0049] 100: Stacked Patch Antenna 101: Grounding plane 103: First substrate 105: First patch 107: Second substrate 109: Second patch 113: Power Supply Connector 111: Second diagonal non-radial center slot 115: First diagonal non-radial center slot 300: Array 301:Substrate 303, 305, 307, 309, 311: Stacked patch antennas 400: Method 401, 403, 405, 407, 409, 411: Steps

Claims

1. A stacked patch antenna, comprising: Grounding plane; The first substrate on the grounding plane; A first patch on the first substrate has a first diagonal non-radiative center slot from one side of the first patch; a second substrate on the first patch; a second patch on the second substrate has a second diagonal non-radiative center slot from one side of the second patch similar to that side of the first patch, wherein the second patch is configured as a jumper and overlaps and offsets the first patch; and a power connector having a first conductor directly connected to the ground plane and a second conductor capacitively connected to the first patch through a gap in the first patch and directly connected to the second patch, wherein the diameter of the gap provides an impedance matching mechanism between the first patch and the second patch, and the jumper configuration works in conjunction with the first diagonal non-radiative center slot and the second diagonal non-radiative center slot to achieve impedance matching while maintaining phase dispersion stability, wherein the first diagonal non-radiative center slot and the second diagonal non-radiative center slot are configured to achieve phase delay of the current without disturbing the electric field at the edges of the first patch and the second patch.

2. The stacked patch antenna according to claim 1, wherein the ground plane is metal.

3. The stacked patch antenna according to claim 1, wherein the feed connector is a coaxial connector.

4. The stacked patch antenna according to claim 1, wherein the first substrate and the second substrate each include an insulator.

5. The stacked patch antenna according to claim 4, wherein the insulator comprises an isotropic thermosetting microwave material.

6. The stacked patch antenna according to claim 1, wherein the first diagonal non-radiating center slot and the second diagonal non-radiating center slot have the same orientation.

7. The stacked patch antenna according to claim 1, wherein the first diagonal non-radiating center slot and the second diagonal non-radiating center slot have opposite orientations.

8. The stacked patch antenna according to claim 1, wherein the ground plane is 4 inches × 4 inches, the first substrate and the second substrate are each 2 inches × 2 inches, and the height of the first substrate and the second substrate is 0.2 inches.

9. A stacked patch antenna array, comprising: Multiple stacked patch antennas are disposed on a substrate, each of the stacked patch antennas comprising: a first substrate on a ground plane; a first patch on the first substrate having a first diagonal non-radiating center slot from one side of the first patch; a second substrate on the first patch; a second patch on the second substrate having a second diagonal non-radiating center slot from one side of the second patch similar to that side of the first patch, wherein the second patch is configured as a jumper and overlaps and offsets the first patch; and a feed connector having a first conductor directly connected to the ground plane and a second conductor capacitively connected to the first patch through a gap in the first patch and directly connected to the second patch, wherein the diameter of the gap provides an impedance matching mechanism between the first patch and the second patch, and the jumper configuration cooperates with the first and second diagonal non-radiating center slots to achieve impedance matching while maintaining phase dispersion stability. The first and second diagonal non-radiative center slots are configured to achieve phase delay of the current without disturbing the electric field at the edges of the first and second patches.

10. The stacked patch antenna array of claim 9, wherein the plurality of stacked patch antennas comprises five stacked patch antennas arranged in a circular manner, with a spacing of 3.175 inches between adjacent stacked patch antennas.

11. The stacked patch antenna array according to claim 10, wherein the patch radius between adjacent stacked patch antennas is the interval in inches divided by 2 sin 36 degrees.

12. A method for manufacturing a stacked patch antenna, comprising: Deposition grounding plane; A first substrate formed on the grounding plane; A first patch formed on the first substrate has a first diagonal non-radiative center slot from one side of the first patch; a second substrate formed on the first patch; a second patch formed on the second substrate has a second diagonal non-radiative center slot from one side of the second patch similar to that side of the first patch, wherein the second patch is configured as a jumper and overlaps and offsets the first patch; A power supply connector is formed having a first conductor directly connected to the ground plane and a second conductor capacitively connected to the first patch by passing through a gap in the first patch and directly connected to the second patch, wherein the diameter of the gap provides an impedance matching mechanism between the first patch and the second patch, and the jumper is configured to cooperate with the first diagonal non-radiating center slot and the second diagonal non-radiating center slot to achieve impedance matching while maintaining phase dispersion stability, wherein the first diagonal non-radiating center slot and the second diagonal non-radiating center slot are configured to achieve phase delay of the current without disturbing the electric field at the edges of the first patch and the second patch.

13. The method according to claim 12, wherein the grounding plane is metallic.

14. The method according to claim 12, wherein the first substrate and the second substrate each include an insulator.

15. The method according to claim 14, wherein the insulator comprises an isotropic thermosetting microwave material.

16. The method according to claim 12, wherein the first diagonal non-radiative central slot has the same orientation as the second diagonal non-radiative central slot.

17. The method according to claim 12, wherein the first diagonal non-radiative central slot has opposite orientations to the second diagonal non-radiative central slot.

18. The method according to claim 12, wherein the ground plane is 4 inches × 4 inches, the first substrate and the second substrate are each 2 inches × 2 inches, and the height of the first substrate and the second substrate is 0.2 inches.

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