An asymmetric multilayer stacked rectangular microstrip antenna

Abstract

This invention discloses an asymmetric multilayer stacked rectangular microstrip antenna, comprising an upper substrate and a lower substrate. The upper substrate includes a microstrip radiating patch on its upper surface, with a partially grounded patch disposed on the lower surface of the upper substrate. The upper surface of the lower substrate is configured as a metasurface reflector, located directly below the partially grounded patch. A non-contact air gap is formed between the metasurface reflector and the partially grounded patch to create an electromagnetic wave reflection enhancement layer. Experimental results show that, after metamaterial optimization, the antenna gain of this invention jumps from a baseline of 2.44 dB to 5.08 dB, an increase of 108%; the radiation efficiency significantly improves from 49.15% to 89.6%, an efficiency improvement of 82.3%; and the operating bandwidth expands from 4.4% to 12.5%, achieving a nearly three-fold increase in bandwidth. Furthermore, its wide bandwidth and high efficiency characteristics are particularly suitable for the stringent requirements of compact antennas in modern wireless systems such as 5G communication and satellite navigation.

Description

Technical Field

[0001] This invention belongs to the field of communication network technology, and particularly relates to an asymmetric multilayer stacked rectangular microstrip antenna. Background Technology

[0002] Microstrip antennas are widely favored in GHz band (f > 0.5 GHz) applications such as mobile communications (handheld devices), aerospace (aircraft / satellites), and military equipment (missile guidance) due to their advantages including low profile, high mechanical strength, low cost, ease of fabrication, and good compatibility with monolithic microwave integrated circuits (MMICs). However, microstrip antennas typically have low power, high Q value, large sidelobe radiation, and very limited bandwidth. Furthermore, for simple patch geometries, the frequency bandwidth of microstrip antennas is extremely narrow, at most only a few percent. Therefore, existing microstrip antennas suffer from inherent defects such as low radiation efficiency and low gain, which severely restricts their practical engineering applications. Summary of the Invention

[0003] To overcome the shortcomings and deficiencies of the prior art, the present invention aims to provide an asymmetric multilayer stacked rectangular microstrip antenna.

[0004] This invention is implemented as follows: an asymmetric multilayer stacked rectangular microstrip antenna, the rectangular microstrip antenna including an upper substrate and a lower substrate; the upper substrate includes a microstrip radiating patch located on its upper surface, and a partially grounded patch of the microstrip radiating patch is disposed on the lower surface of the upper substrate; the upper surface of the lower substrate is provided with a metasurface reflector, the metasurface reflector being located directly below the partially grounded patch; wherein, a non-contact air gap is provided between the metasurface reflector and the partially grounded patch to form an electromagnetic wave reflection enhancement layer.

[0005] Preferably, the substrate is an FR4 epoxy resin substrate.

[0006] Preferably, the resonant frequency of the microstrip radiating patch is controlled by the size of the microstrip radiating patch, the feed line is optimized by HFSS, and the signal transmission adopts a microstrip feeding method.

[0007] Preferably, the grounding area of ​​the partial grounding patch is determined to be of optimal size by parametric scanning using ANSYS HFSS.

[0008] Preferably, the metasurface reflector is composed of a parallel array of dipole patches, wherein the long axis of the dipole patch is parallel to the radiating edge of the radiating patch.

[0009] Preferably, the electromagnetic characteristics of the metasurface reflector composed of dipole strips, etc., are as follows: it produces a negative refractive index response Re(ε) = -2.7 and Re(μ) = -1.3 at 2.4 GHz.

[0010] Compared to the shortcomings and deficiencies of existing technologies, this invention has the following beneficial effects: The metamaterial structure designed in this invention consists of a periodically arranged parallel dipole array, with a single dipole unit size of Xg × 1.25 mm (length × width) and an array period of 5 mm. By arranging the long axis of the dipoles parallel to the radiating edge of the patch antenna, the co-polarization characteristics of the radiation field are effectively enhanced. Experimental results show that after metamaterial optimization, the antenna gain jumps from the baseline value of 2.44 dB to 5.08 dB, an increase of 108%; the radiation efficiency significantly improves from 49.15% to 89.6%, an efficiency improvement rate of 82.3%; and the operating bandwidth expands from 4.4% to 12.5%, achieving a nearly three-fold increase in bandwidth. The synergistic optimization of three sets of key parameters confirms the significant improvement effect of the metamaterial structure on the overall performance of the microstrip antenna. This invention provides a new technical path for the design of high-performance microstrip antennas, and its wide bandwidth and high efficiency characteristics are particularly suitable for the stringent requirements of compact antennas in modern wireless systems such as 5G communication and satellite navigation. Attached Figure Description

[0011] Figure 1 This is an exploded view of the asymmetric multilayer stacked rectangular microstrip antenna of the present invention. Figure 2 This is a schematic diagram of the structure of the microstrip radiating patch of the present invention; Figure 3 This is a schematic diagram of the structure of a partial grounding patch of the present invention; Figure 4 This is a schematic diagram of the structure of the metasurface (MS) reflector of the present invention; Figure 5 This is a comparison of simulated scattering parameters of rectangular microstrip patches with and without metasurface reflectors; Figure 6 It is a rectangular microstrip patch antenna with and without a metasurface reflector. Comparison of radiation patterns of electric field components within a plane. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0013] This invention discloses an asymmetric multilayer stacked rectangular microstrip antenna, such as... Figures 1-4As shown, the rectangular microstrip antenna includes an upper substrate and a lower substrate; the upper substrate includes a microstrip radiating patch on its upper surface, and a partial grounding patch of the microstrip radiating patch is disposed on the lower surface of the upper substrate; the upper surface of the lower substrate is provided with a metasurface reflector, and the metasurface reflector is located directly below the partial grounding patch; wherein, a non-contact air gap is provided between the metasurface reflector and the partial grounding patch to form an electromagnetic wave reflection enhancement layer.

[0014] In this embodiment of the invention, a rectangular microstrip antenna ( Figure 1 It adopts an asymmetric multilayer stacked structure, including microstrip radiating patches ( Figure 2 ), partial grounding patch ( Figure 3 ) and meta-surface (MS) reflectors ( Figure 4 The system comprises three core modules. The MS reflector is innovatively positioned beneath a partially grounded patch, with the two components forming a non-contact levitation structure through a precise 12.4 mm spacing, creating an electromagnetic wave reflection enhancement layer. This architecture maintains the compact characteristics of a microstrip antenna (overall dimensions 53.6 × 61.25 mm²) while overcoming the traditional bandwidth-gain constraint through a spatial coupling mechanism.

[0015] In practical applications, the parametric design of key components of the rectangular microstrip antenna of this invention includes: 1. Microstrip radiating patch and feeding method ( Figure 2 ) Substrate material: FR4 epoxy resin substrate, 1.6 mm thick, with dimensions of 53.6 mm long × 61.25 mm wide.

[0016] The resonant frequency of the microstrip radiating patch is 2.4 GHz. The resonant frequency is controlled by the size of the microstrip radiating patch, which is 26.8 mm long and 38 mm wide (in this embodiment of the invention, it is controlled by the patch length L = 61.25 mm).

[0017] Feeder design: 50Ω, dimensions are 26.8 mm long × 38 mm wide. Through HFSS optimization, the width of the microstrip line in contact with the ground is set to 3.2 mm. The signal transmission adopts microstrip feeding method with a microstrip line width of 3.2 mm.

[0018] 2. Partial grounding patch ( Figure 3 ) In this embodiment of the invention, the grounding area of ​​a portion of the grounding patch (i.e., a grounding patch whose area is used for grounding) is strategically reduced to a width of 3.2 mm, and the optimal size is determined by parametric scanning using ANSYS HFSS.

[0019] Mechanism of action: The introduction of a controllable current cutoff effect extends the bandwidth of the traditional fully grounded structure from <5% to 12.5%.

[0020] 3. Metasurface reflectors ( Figure 4 ) The metasurface reflector is composed of a parallel array of dipole patches (a periodically arranged cross-shaped metal pattern with a period of 6 mm), with the major axis of the dipole patches parallel to the radiating edge of the radiating patch. In this embodiment, the spacing between adjacent dipole patches is 5 mm, and the dimensions of a single dipole patch are 53.6 mm in length and 3.2 mm in width. Furthermore, the vertical height between the metasurface reflector and the partially grounded patch is 12.4 mm.

[0021] The electromagnetic characteristics of the metasurface reflector composed of dipole strips are as follows: it produces a negative refractive index response at 2.4 GHz (Re(ε)=-2.7, Re(μ)=-1.3); the installation spacing is determined to be 12.4 mm air layer spacing by the λ / 4 phase matching principle.

[0022] 4. Performance optimization mechanism: (1) Bandwidth expansion principle The composite resonant system formed by the partial grounding patch and the MS reflector increases the effective electrical length by 2.3 times, and the measured -10dB impedance bandwidth increases from 4.8% of the traditional structure to 15.6%.

[0023] (2) Gain Enhancement Strategy The MS reflector improves forward radiation efficiency from 67% to 89% by constructing artificial magnetic conductor (AMC) characteristics, achieving a gain jump from 5.2 dB to 7.8 dB, while maintaining 3D pattern symmetry (half-power beamwidth 76°±2°).

[0024] (3) Cross-polarization suppression The orthogonal cross-shaped MS element design achieves a cross-polarization ratio of -27.5 dB (compared to -15.3 dB before optimization), meeting the polarization purity requirements of the IEEE 802.11n protocol for MIMO antennas.

[0025] Simulations were conducted using electromagnetic simulation software (such as HFSS). The effectiveness of the designed product was verified by comparing simulation results with and without a metal shield (MS) and with a complete ground plane. Relevant national standards were cited as verification basis, including GB / T 9410-2008 "General Technical Conditions for Mobile Communication Antennas", GB / T 12190-2021 "Measurement Method for Shielding Effectiveness of Electromagnetic Shielding Rooms", and GB / T 30142-2013 "Measurement Method for Shielding Effectiveness of Planar Electromagnetic Shielding Materials", clearly specifying that performance indicators must meet the national standards for testing microstrip antenna gain, bandwidth, and radiation efficiency. Experimental results are as follows: Figure 5 , Figure 6 As shown, S11 (reflection coefficient) is an important parameter for evaluating antenna performance; it represents the ratio of reflected power to incident power at the antenna input. A lower S11 value indicates better antenna matching and lower reflection loss. Figure 5 As can be seen, the S11 values ​​of the microstrip patch antenna with and without metal shielding are -38.24 dB and -37.49 dB, respectively. dB (decibels) is a logarithmic unit used to represent the ratio of two power levels. A negative value indicates that the reflected power is much smaller than the incident power, so both values ​​indicate that the antenna has good matching. Figure 6 for A comparison of planar radiation patterns. It illustrates the effect of rectangular microstrip patch antennas with and without metasurface reflectors. A comparison of the radiation direction distributions of the same polarization components and cross polarization components within the plane. Figure 6 The comparison diagrams, from two orthogonal critical planes, verify the radiation modulation effect of the MS: by enhancing the main polarization component and suppressing radiation leakage in cross-polarization and non-target directions, the antenna radiation energy is more concentrated in the effective direction, ultimately supporting the overall performance improvement—compared to the antenna without MS, the peak gain of the antenna with MS increases from 2.44dB to 5.08dB, and the radiation efficiency increases from 49.15% to 89.6%.

[0026] The experimental results above show that, after optimization with metamaterials, the antenna gain of this invention jumped from the baseline value of 2.44 dB to 5.08 dB, an increase of 108%; the radiation efficiency significantly improved from 49.15% to 89.6%, an efficiency improvement rate of 82.3%; and the operating bandwidth expanded from 4.4% to 12.5%, achieving a nearly three-fold increase in bandwidth. The synergistic optimization of these three key parameters confirms the significant improvement effect of metamaterial structures on the overall performance of microstrip antennas.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rectangular microstrip antenna of asymmetric multi-layer stack, characterized by, The rectangular microstrip antenna includes an upper substrate and a lower substrate; the upper substrate includes a microstrip radiating patch on its upper surface, and a partial grounding patch of the microstrip radiating patch is disposed on the lower surface of the upper substrate; the upper surface of the lower substrate is provided with a metasurface reflector, and the metasurface reflector is located directly below the partial grounding patch; wherein, a non-contact air gap is provided between the metasurface reflector and the partial grounding patch to form an electromagnetic wave reflection enhancement layer.

2. The rectangular microstrip antenna as described in claim 1, characterized in that, The substrate is an FR4 epoxy resin substrate.

3. The rectangular microstrip antenna as described in claim 2, characterized in that, The resonant frequency of the microstrip radiating patch is controlled by the size of the microstrip radiating patch, the feed line is optimized by HFSS, and the signal transmission adopts a microstrip feeding method.

4. The rectangular microstrip antenna as described in claim 3, characterized in that, The grounding area of ​​the aforementioned grounding patch was determined to be of optimal size using parametric scanning with ANSYS HFSS.

5. The rectangular microstrip antenna as described in claim 4, characterized in that, The metasurface reflector is composed of a parallel array of dipole patches, the long axis of which is parallel to the radiating edge of the radiating patch.

6. The rectangular microstrip antenna as described in claim 5, characterized in that, The electromagnetic characteristics of the metasurface reflector composed of dipole strips are as follows: it produces a negative refractive index response Re(ε) = -2.7 and Re(μ) = -1.3 at 2.4 GHz.

Images