Miniaturized broadband non-reflection filtering antenna and communication equipment

Abstract

The invention provides a miniaturized broadband non-reflection filtering antenna and communication equipment, and relates to the field of communication antennas. The antenna comprises a hybrid coupling resonance system and a matched absorption network, wherein the hybrid coupling resonance system comprises a main radiation groove which is formed in a metal floor and is of a split ring structure, and two parasitic radiation grooves which are of a U-shaped structure and are located on the two sides of the main radiation groove respectively; the matching absorption network comprises an absorption resistor connected with the feed microstrip line in parallel and an absorption microstrip line connected with the absorption resistor in series. According to the embodiment of the invention, the absorption circuit is integrated on the structure, so that the antenna has the non-reflection characteristic in the range of 1.27-2.31 GHz far beyond the radiation bandwidth, the defect that the radio frequency front-end performance is deteriorated due to in-band reflection and out-of-band energy reflection back to a transmitting channel of a traditional antenna is effectively overcome, and the electromagnetic compatibility and the linear characteristic of the whole system are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of communication antennas, and more specifically to a miniaturized broadband non-reflective filter antenna and communication equipment. Background Technology

[0002] In the face of miniaturized and complex electromagnetic environments in wireless communication scenarios, reflectionless antennas, as an emerging technology, demonstrate great potential in solving the interference resistance and high reliability problems of traditional filter antennas by integrating multi-functional "radiation-absorption" characteristics. On the one hand, reflectionless antennas can achieve efficient radiation within the selected passband, ensuring stable transmission of communication signals; on the other hand, by absorbing out-of-band interference signals, reflectionless antennas can effectively achieve out-of-band matching between the antenna and the RF front-end circuit, avoiding problems such as performance degradation and reduced sensitivity of back-end active devices. Currently, reflectionless antennas generally adopt the frequency complementary duplex method, but this method results in high design complexity.

[0003] For example, Chinese patent document CN116613533A (application number 2023107367792) discloses an embedded anti-reflection microwave antenna. This antenna adds a defective microstrip structure by slotting it into a patch, achieving an anti-reflection effect without increasing the size, but with a narrow radiation bandwidth and limited application range. Another example is Chinese patent document CN120262003A (application number 2025105723679), which discloses a broadband anti-reflection filter antenna. This antenna uses two microstrip band-stop filters, resulting in a complex antenna structure. Furthermore, none of the above patents consider the application scenarios of slotted antennas. Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a miniaturized wideband anti-reflection filter antenna and communication device, solving the technical problem of how to provide a simple structure and high-performance miniaturized wideband anti-reflection filter antenna.

[0005] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: A miniaturized broadband non-reflective filter antenna includes a dielectric substrate and a metal ground plane stacked sequentially from top to bottom, as well as a coaxial cable; The dielectric substrate is provided with a fed microstrip line, and the metal ground plane is provided with a hybrid coupling resonant system; Along the length of the feed microstrip line, the terminal of the feed microstrip line is connected to the metal ground plane through a first metal via. In the width direction of the feed microstrip line, the feed microstrip line is connected in parallel with the absorption microstrip line through an absorption resistor, and the terminal of the absorption microstrip line is connected to the metal ground plane through a second metal via; wherein the length of the absorption microstrip line is one-quarter wavelength of the antenna operating frequency; The inner conductor of the coaxial cable is connected to the feed microstrip line, and the outer conductor is connected to the metal ground plane.

[0006] Preferably, the hybrid coupled resonant system includes a main radiating slot that forms a slot coupling with the fed microstrip line and at least one parasitic radiating slot that forms secondary radiation with the coupled electromagnetic field.

[0007] Preferably, the parasitic radiation trough includes a first parasitic radiation trough and a second parasitic radiation trough, which are located on both sides of the main radiation trough.

[0008] Preferably, the length of the main radiating slot is half the wavelength of the antenna's operating frequency.

[0009] Preferably, the main radiation groove has an overall open ring structure.

[0010] Preferably, the lengths of the first parasitic radiation trough and the second parasitic radiation trough are both half the wavelength of the frequency at their respective radiation zero points.

[0011] Preferably, both the first parasitic radiation trough and the second parasitic radiation trough are U-shaped.

[0012] Preferably, the feeding microstrip line and the absorbing microstrip line are processed by etching.

[0013] Preferably, the metal ground plane, the feeding microstrip line, and the absorbing microstrip line are made of copper; the dielectric substrate is made of Rogers RO3003.

[0014] A communication device comprising a miniaturized broadband non-reflective filtered antenna as described above.

[0015] (III) Beneficial Effects This invention provides a miniaturized wideband reflection-free filter antenna and communication device. Compared with the prior art, it has the following advantages: This invention connects a feed microstrip line to an absorption microstrip line via an absorption resistor on one side of the feed structure. The absorption microstrip line has a length of one-quarter wavelength of the antenna's operating frequency, and its termination is connected to a metal ground plane via a metal via to achieve a ground short circuit. The one-quarter wavelength absorption microstrip line has impedance transformation capabilities. When the antenna operates at its resonant frequency, the impedance at the input port of the absorption microstrip line approaches infinity, equivalent to an open circuit, and the series absorption resistor does not affect the radiation function. When the antenna operates away from the resonant frequency, the absorption resistor takes effect, significantly improving the system's out-of-band absorption capability. Therefore, using a resistor-loaded, short-circuited one-quarter wavelength transmission line as the absorption unit allows for independent single-frequency control of both radiation and absorption functions. Furthermore, since the transmission length of the absorption microstrip line is only one-quarter wavelength, it does not significantly increase the antenna size, achieving a miniaturized absorption function design. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is an overall schematic diagram of a miniaturized broadband non-reflective filter antenna provided in an embodiment of the present invention; Figure 2 A front view of a miniaturized broadband non-reflective filter antenna provided in an embodiment of the present invention; Figure 3 A top view of a miniaturized broadband non-reflective filter antenna provided in an embodiment of the present invention; Figure 4 A front view of a matching absorption network provided in an embodiment of the present invention; Figure 5 Impedance and gain curves of a miniaturized broadband non-reflective filter antenna provided in an embodiment of the present invention; Figure 6 A radiation efficiency curve of a miniaturized broadband non-reflective filter antenna provided for an embodiment of the present invention; Figure 7 The radiation pattern of a miniaturized broadband non-reflective filter antenna in the XOZ plane is provided in an embodiment of the present invention; Figure 8 The radiation pattern of a miniaturized broadband non-reflective filter antenna in the YOZ plane is provided for an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1—Dielectric substrate, 2—Main radiating trench, 3—First parasitic radiating trench, 4—Second parasitic radiating trench, 5—Feed microstrip line, 6—Absorbing microstrip line, 7—Absorbing resistor, 8—Coaxial cable, 9—First metal via, 10—Second metal via, 11—Metal ground plane. X—length direction of the feed microstrip line, Y—width direction of the feed microstrip line, Z—thickness direction of the antenna. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0021] Example 1: like Figures 1-4 As shown, this embodiment of the invention discloses a miniaturized broadband non-reflective filter antenna, including a dielectric substrate 1 and a metal ground plane 11 stacked from top to bottom, a feed microstrip line 5, an absorption microstrip line 6 and an absorption resistor 7 disposed on the upper surface of the dielectric substrate 1, a hybrid coupling resonant system disposed on the metal ground plane 11, and a coaxial cable 8.

[0022] Specifically: For example, the feeding microstrip line 5 and the absorbing microstrip line 6 can be obtained by etching on the upper surface of the dielectric substrate 1.

[0023] like Figure 1 and Figure 3 As shown, along the length of the feed microstrip line 5, the terminal of the feed microstrip line 5 is connected to the metal ground plane 11 through the first metal via 9 to achieve grounding.

[0024] like Figure 1 , Figure 3 and Figure 4 As shown, in the width direction of the feed microstrip line 5, the feed microstrip line 5 is connected in parallel with the absorption microstrip line 6 through the absorption resistor 7. More specifically, Figure 4The connections between the components of the matching absorption network shown are as follows: the feed microstrip line 5 is connected in parallel with the absorption resistor 7, the absorption resistor 7 is connected in series with the input terminal of the absorption microstrip line 6, and the terminal of the absorption microstrip line 6 is grounded. Furthermore, the terminal of the absorption microstrip line 6 is connected to the metal ground plane 11 through a second metal via 10 to achieve a ground short circuit. Specifically, in this embodiment of the invention, the length of the absorption microstrip line is designed to be one-quarter of the antenna's operating frequency to enable it to perform impedance transformation.

[0025] like Figure 2 As shown, the inner conductor of the coaxial cable 8 is connected to the feed microstrip line 5, and the outer conductor is connected to the metal ground plane 11.

[0026] This invention employs a quarter-wavelength transmission line with resistive loading and short-circuiting as the absorption unit, enabling independent single-frequency control of both radiation and absorption functions. Furthermore, since the transmission length of the absorption microstrip line is only a quarter wavelength, it does not significantly increase the antenna size, achieving a miniaturized design for the absorption function.

[0027] In an alternative implementation, such as Figure 1 and Figure 3 As shown, the hybrid coupled resonant system includes a main radiating slot 2 (main resonator) that is slot-coupled with the fed microstrip line 5 and at least one parasitic radiating slot (parasitic resonator) that forms secondary radiation with the coupled electromagnetic field.

[0028] like Figure 1 and Figure 3 As shown, the parasitic radiation trough includes a first parasitic radiation trough 3 and a second parasitic radiation trough 4, which are located on both sides of the main radiation trough 2.

[0029] like Figure 1 and Figure 3 As shown, the length of the main radiating slot 2 is half the wavelength of the antenna's operating frequency, and the overall structure is an open-loop structure. It should be noted that the open-loop structure effectively reduces the antenna size, which is beneficial for miniaturization design.

[0030] like Figure 1 and Figure 3 As shown, the lengths of the first parasitic radiation slot 3 and the second parasitic radiation slot 4 are both half the wavelength of the frequency at their respective radiation null points, and both exhibit a U-shaped structure. It should be noted that the U-shaped structure is beneficial for impedance matching, and there is no need to specifically limit the orientation of the opening of the U-shaped structure.

[0031] This invention is based on near-field parasitic coupling technology. By loading a near-field parasitic unit structure (designing two U-shaped parasitic radiation slots), it is used to introduce corresponding out-of-band radiation zeros, thereby improving out-of-band selectivity and filtering performance.

[0032] In one alternative embodiment, the dielectric substrate 1 is made of Rogers RO3003 or other high-frequency circuit dielectric substrates; the metal ground plane 11, the feed microstrip line 5, and the absorber microstrip line 6 are made of copper or other metal materials.

[0033] To help understand the embodiments of the present invention, a specific example is provided below: like Figure 3 As shown, the dielectric substrate 1 has a length of l1 = 60 mm and a width of w1 = 40 mm; the feed microstrip line 5 has a length of l8 = 34 mm and a width of w1 = 40 mm. 10 =1mm; the length of the absorbing microstrip line 6 is l7=24.5mm and the width is w9=7mm; the length of the main radiating slot 3 corresponds to 0.5 wavelengths of the antenna operating frequency; the lengths of the first parasitic radiating slot 4 and the second parasitic radiating slot 5 are 0.5 wavelengths of the frequency at their respective radiation null points; the resistance of the absorbing resistor 7 is R=100ohm.

[0034] like Figure 4 As shown, the absorbing microstrip line 6 and the absorbing resistor 7, which are connected in parallel to the right side of the feed microstrip line 5, are offset from the starting segment of the feed microstrip line by a distance of l. 10 =11mm.

[0035] The miniaturized broadband non-reflective filter antenna in the above example was simulated and analyzed using the 3D electromagnetic (EM) simulation software HFSS21.0. The resulting parameters and dimensions of the antenna are shown in Table 1 below. Table 1 Optimal Dimensions for Each Parameter Based on the above parameters, HFSS was used to analyze the S11 parameters, gain, and radiation efficiency parameters of the miniaturized broadband non-reflective filter antenna in the above embodiment. The analysis results are as follows: like Figure 5 As shown, the -10dB impedance curve of this example non-reflective antenna has a bandwidth of 1.04 GHz, from 1.27 GHz to 2.31 GHz, with a relative bandwidth of 58.1%; the peak gain is 4.81 dBi, and the gain suppression is 9.42 dBi.

[0036] like Figure 6 As shown, the peak radiation efficiency of the non-reflective antenna in this example is 98.27%.

[0037] like Figure 7 As shown, the radiation pattern of the non-reflective antenna in this example in the XOZ plane at 1.734 GHz exhibits high-gain co-polarization and cross-polarization suppression.

[0038] like Figure 8As shown, the radiation pattern of the non-reflective antenna in this example in the YOZ plane at 1.734 GHz exhibits high-gain co-polarization and cross-polarization suppression.

[0039] Example 2: This invention discloses a communication device, including the miniaturized wideband non-reflective filter antenna described in Embodiment 1.

[0040] In summary, compared with existing technologies, it has the following beneficial effects: 1. In this embodiment of the invention, a quarter-wavelength transmission line with resistive loading and short-circuiting is used as the absorption unit, which enables independent single-frequency control of radiation and absorption functions. Furthermore, since the transmission length of the absorption microstrip line is only a quarter wavelength, it does not significantly increase the antenna size, achieving a miniaturized design for the absorption function.

[0041] 2. The embodiments of the present invention are based on near-field parasitic coupling technology. By loading a near-field parasitic unit structure (designing two U-shaped parasitic radiation slots), the corresponding out-of-band radiation zeros are introduced to improve out-of-band selectivity and filtering performance.

[0042] 3. By integrating an absorption circuit into the structure, the antenna exhibits non-reflective characteristics in the range of 1.27~2.31GHz, which is far beyond its radiation bandwidth. This effectively solves the defects of traditional antennas, such as in-band reflection and out-of-band energy reflection back to the transmission channel, which degrade the performance of the radio frequency front-end. It significantly improves the overall electromagnetic compatibility performance and linearity of the system.

[0043] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A miniaturized broadband non-reflective filter antenna, characterized in that, It includes a dielectric substrate (1) and a metal ground plane (11) stacked from top to bottom, and a coaxial cable (8). The dielectric substrate (1) is provided with a feed microstrip line (5), and the metal ground plane (11) is provided with a hybrid coupling resonant system; Along the length of the feed microstrip line (5), the terminal of the feed microstrip line (5) is connected to the metal ground plane (11) through a first metal via (9); In the width direction of the feed microstrip line (5), the feed microstrip line (5) is connected in parallel with the absorber microstrip line (6) through the absorber resistor (7), and the terminal of the absorber microstrip line (6) is connected to the metal ground plane (11) through the second metal via (10); wherein the length of the absorber microstrip line is one-quarter wavelength of the antenna operating frequency. The inner conductor of the coaxial cable (8) is connected to the feed microstrip line (5), and the outer conductor is connected to the metal ground plane (11).

2. The miniaturized broadband non-reflective filter antenna as described in claim 1, characterized in that, The hybrid coupled resonant system includes a main radiation slot (2) that forms a slot coupling with the feed microstrip line (5) and at least one parasitic radiation slot that forms secondary radiation with the coupled electromagnetic field.

3. The miniaturized broadband reflection-free filter antenna as described in claim 2, characterized in that, The parasitic radiation trough includes a first parasitic radiation trough (3) and a second parasitic radiation trough (4), with the first parasitic radiation trough (3) and the second parasitic radiation trough (4) located on both sides of the main radiation trough (2).

4. The miniaturized wideband reflection-free filter antenna as described in claim 2, characterized in that, The length of the main radiating slot (2) is half the wavelength of the antenna operating frequency.

5. The miniaturized broadband non-reflective filter antenna as described in claim 4, characterized in that, The main radiation groove (2) is generally presented as an open ring structure.

6. The miniaturized broadband non-reflective filter antenna as described in claim 3, characterized in that, The lengths of the first parasitic radiation trough (3) and the second parasitic radiation trough (4) are both half the wavelength of the frequency at the zero point of radiation.

7. The miniaturized broadband non-reflective filter antenna as described in claim 6, characterized in that, Both the first parasitic radiation trough (3) and the second parasitic radiation trough (4) are U-shaped structures.

8. The miniaturized broadband non-reflective filter antenna as described in claim 1 or 2, characterized in that, The feeding microstrip line (5) and the absorbing microstrip line (6) are processed by etching.

9. The miniaturized broadband reflection-free filter antenna as described in claim 1 or 2, characterized in that, The metal floor (11), the feed microstrip line (5) and the absorber microstrip line (6) are made of copper; the dielectric substrate (1) is made of Rogers RO3003.

10. A communication device, characterized in that, Includes the miniaturized broadband non-reflective filter antenna as described in any one of claims 1 to 9.

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