A differential decoupling antenna that combines stepped and uniform impedance resonators

Abstract

The application discloses a differential decoupling antenna of a comprehensive step and uniform impedance resonator, which is characterized in that step resonators and uniform impedance resonators are arranged on the upper and lower sides of two patch units respectively and parallel to the patch units, and the step resonators and the uniform impedance resonators are arranged in the same direction as the differential ports, so that a weak field is generated near the feeding ports of the coupled patch units, and the decoupling of the differential antenna is realized. The width of the left and right widened parts of the step impedance resonator is twice that of the middle part, the left end of the step impedance resonator is located between the differential ports one, and the right end is located between the differential ports two. The left end of the uniform impedance resonator is located between the left edge of the left patch unit and the left feeding port, and the right end is located between the right edge of the right patch unit and the right feeding port. In this arrangement, the radiation pattern can be corrected, the radiation efficiency can be improved, and the 3dB beam width can be widened.

Description

Technical Field

[0001] This invention relates to a wireless communication device, and more particularly to a differential decoupling antenna. Background Technology

[0002] Differential antennas can effectively improve performance stability and reduce performance fluctuations caused by asymmetrical structures. They also possess strong anti-interference capabilities and can enhance the transmission efficiency of differential-mode signals, thereby improving signal anti-interference performance. With the rapid development of wireless communication technology, device miniaturization has become an inevitable trend, and the importance of tightly packed multi-element patch antenna arrays is increasingly prominent. However, when differential antennas are tightly arranged to save space, mutual interference between antennas can cause many problems, such as distorted radiation patterns, narrowed 3dB beamwidth, and decreased efficiency. Currently, most existing decoupling techniques are applicable to single-fed antennas, which can reduce coupling between single-fed antennas to a certain extent, but cannot be directly applied to differential-fed antennas. This is because differential-fed antennas have more feed ports and more complex coupling paths. Therefore, it is urgent to explore effective methods to reduce mutual coupling between differential antenna array elements.

[0003] Existing differential decoupling techniques achieve high levels of decoupling through decoupling networks, but their radiation patterns still exhibit shifts, and their efficiency and beamwidth are insufficient to meet the requirements of high-performance antenna arrays. To mitigate the radiation pattern shift issue, current technologies utilize characteristic modes and H-shaped structures to achieve low mutual coupling and relatively uniform radiation patterns. However, these radiation patterns still have room for further optimization and similarly do not address efficiency and 3dB beamwidth, thus failing to meet the demands of high-performance antenna arrays. In summary, existing technologies, while achieving low mutual coupling, struggle to simultaneously reduce radiation pattern shift, improve radiation efficiency, and widen the 3dB beamwidth, thus failing to fully meet the requirements of high-performance antenna arrays. Summary of the Invention

[0004] Purpose of the invention: To address the aforementioned existing technologies, a differential decoupling antenna combining a step resonator and a uniform impedance resonator is proposed, which optimizes the radiation pattern, improves radiation efficiency, and widens the beamwidth by 3dB.

[0005] Technical Solution: A differential decoupling antenna integrating step and uniform impedance resonators, comprising a top metal layer, an intermediate dielectric substrate layer, and a bottom metal layer; the top metal layer includes two parallel spaced metal patches, each metal patch being fed by two coaxial probes, with the four coaxial probes located on the same horizontal line; the top metal layer also includes a step impedance metal strip located outside the upper edges of the two metal patches, and a uniform impedance metal strip located outside the lower edges of the two metal patches; wherein, the step impedance metal strip is composed of widened portions at the left and right ends and a middle portion, the width of the widened portions at the left and right ends being twice the width of the middle portion; in the length direction... The left end of the stepped impedance metal strip is located between the feed points of the two coaxial probes of the left metal patch, and the right end is located between the feed points of the two coaxial probes of the right metal patch. In the length direction, the left end of the uniform impedance metal strip is located between the left edge of the left metal patch and the feed point of the left coaxial probe, and the right end is located between the right edge of the right metal patch and the feed point of the right coaxial probe. The two metal patches serve as two radiating elements of the antenna. The stepped impedance metal strip and the impedance metal strip, together with the intermediate dielectric substrate layer and the bottom metal layer, respectively form a stepped impedance resonator and a uniform impedance resonator, serving as a decoupling structure for the two radiating elements.

[0006] Furthermore, the length and width of the two metal patches are both between 0.20λ0 and 0.25λ0, the edge-to-edge spacing of the two metal patches is between 0.020λ0 and 0.025λ0, the center-to-center spacing is between 0.25λ0 and 0.30λ0, and the center-to-center spacing of the feed points of the two coaxial probes on the same metal patch is between 0.050λ0 and 0.055λ0, where λ0 is the free space wavelength corresponding to the center frequency.

[0007] Furthermore, the overall length of the stepped impedance metal strip is between 0.25λ0 and 0.30λ0, the length of the middle section is between 0.10λ0 and 0.15λ0, and the width of the middle section is between 0.010λ0 and 0.015λ0; the length of the uniform impedance metal strip is between 0.50λ0 and 0.55λ0, and the width is between 0.010λ0 and 0.015λ0.

[0008] Furthermore, the edge-to-edge distance between the two metal patches and the widened portion of the stepped impedance metal strip is between 0.010λ0 and 0.015λ0, and the edge-to-edge distance between the two metal patches and the uniform impedance metal strip is between 0.010λ0 and 0.015λ0.

[0009] Beneficial effects: This invention achieves decoupling of the differential antenna by arranging a step resonator and a uniform impedance resonator parallel to each other on the upper and lower sides of the two patch units, and the step impedance resonator and the uniform impedance resonator are arranged in the same direction as the differential port.

[0010] The width of the widened sections at the left and right ends of the stepped impedance resonator is twice that of the middle section. The left end of the stepped impedance resonator is located between differential ports one and the right end is located between differential ports two. The left end of the uniform impedance resonator is located between the left edge of the left patch unit and the left feed port, and the right end is located between the right edge of the right left patch unit and the right feed port. This couples the energy originally coupled to the coupling patch into the resonator, thereby reducing the influence of the coupling patch radiation on the radiation characteristics of the main patch. With this arrangement, the radiation pattern can be corrected, thereby improving the radiation efficiency and widening the beamwidth by 3dB. Attached Figure Description

[0011] Figure 1 This is a schematic cross-sectional view of the differential decoupling antenna of the present invention.

[0012] Figure 2 This is a top view of the differential decoupling antenna of the present invention.

[0013] Figure 3 This is a schematic diagram of the differential decoupling antenna structure of the present invention from a bottom view.

[0014] Figure 4 The S-parameter curve of the antenna in the example is shown.

[0015] Figure 5 The gain curve of the antenna in the example is shown.

[0016] Figure 6 The simulated radiation pattern of the antenna at 3.43 GHz is shown in the example. Detailed Implementation

[0017] The invention will now be further explained with reference to the accompanying drawings.

[0018] like Figures 1 to 3 As shown, a differential decoupling antenna combining a step resonator and a uniform impedance resonator is composed of a top metal layer 1, an intermediate dielectric substrate layer 2, a bottom metal layer 3, and a coaxial probe group 4. The overall structure is symmetrical about the central axis.

[0019] The top metal layer 1 includes metal patches 11 and 12 of the same size, which are arranged horizontally. y The metal patch 11 is fed by coaxial probes 41 and 42, and the metal patch 12 is fed by coaxial probes 43 and 44. The four coaxial probes are located on the same horizontal line and all pass through the intermediate dielectric substrate layer 2 from the bottom surface of the bottom metal layer 3 to the corresponding metal patch.

[0020] The top metal layer 1 also includes a stepped impedance metal strip 13 located outside the upper edges of the two metal patches, and a uniform impedance metal strip 14 located outside the lower edges of the two metal patches. The stepped impedance metal strip 13 is composed of widened portions at the left and right ends and a middle portion, the width of which is (…). x The shaft is the width of the middle section. x Twice the length of the axis. In the longitudinal direction ( y (Axis), the left end of the stepped impedance metal strip 13 is located between the feed points of coaxial probes 41 and 42, and the right end is located between the feed points of coaxial probes 43 and 44. In the length direction ( y The left end of the uniform impedance metal strip 14 is located between the left edge of the metal patch 11 and the feed point of the coaxial probe 41, and the right end is located between the right edge of the metal patch 12 and the feed point of the coaxial probe 44.

[0021] The length and width of metal patches 11 and 12 are both between 0.20λ0 and 0.25λ0. The edge-to-edge spacing between the two metal patches is between 0.020λ0 and 0.025λ0, and the center-to-center spacing is between 0.25λ0 and 0.30λ0. The center-to-center spacing of the feed points of the two coaxial probes on the same metal patch is between 0.050λ0 and 0.055λ0, where λ0 is the free-space wavelength corresponding to the center frequency. The overall length of the step impedance metal strip 13 ( y The axis is between 0.25λ0 and 0.30λ0, and the length of the middle part is ( y The axis is between 0.10λ0 and 0.15λ0, and the width of the middle part is ( x The axis is between 0.010λ0 and 0.015λ0. The length of the uniform impedance metal strip 14 ( y The axis is between 0.50λ0 and 0.55λ0, and the width is... x The distance between the metal patches 11 and 12 and the widened portion of the stepped impedance metal strip 13 is between 0.010λ0 and 0.015λ0, and the distance between the metal patches 11 and 12 and the middle portion of the stepped impedance metal strip 13 is between 0.025λ0 and 0.030λ0. The distance between the metal patches 11 and 12 and the uniform impedance metal strip 14 is between 0.010λ0 and 0.015λ0.

[0022] In the above structure, metal patches 11 and 12 serve as two radiating elements of the antenna, and coaxial probe group 4 serves as the antenna's feeding structure. Step impedance metal strip 13 and impedance metal strip 14, together with the intermediate dielectric substrate layer 2 and the bottom metal layer 3, respectively, form a step impedance resonator and a uniform impedance resonator, serving as a decoupling structure for the two radiating elements.

[0023] The four coaxial probes 41, 42, 43, and 44 from left to right are designated as ports 1 through 4, respectively. Ports 1 and 2 are referred to as differential port one, and ports 3 and 4 are referred to as differential port two. dd21 S represents the differential mode transmission coefficient between differential port 1 and differential port 2. 31 S represents the transmission coefficient between port 1 and port 3. 32 S represents the transmission coefficient between port 2 and port 3. 41 S represents the transmission coefficient between port 1 and port 4. 42 This represents the transmission coefficient between port 2 and port 4. When differential excitation generates a signal with equal amplitude and opposite direction, it is fed into the metal patch 11 through differential port 1, thereby generating a TM signal on the metal patch 11. 10 The mode radiates outwards, and thanks to the structure of the step impedance resonator, a weak field region is generated near ports 2 and 3; simultaneously, the uniform impedance resonator generates a weak field region near ports 1 and 4, thus S 41 and S 32 The value of S increases, according to the formula S dd21 =1 / 2S 31 -S 32 -S 41 +S 42 As a result, the isolation between differential port one and differential port two becomes higher, thus achieving better isolation characteristics. That is, by setting up a step impedance resonator and a uniform impedance resonator, the energy originally coupled to the coupling patch is coupled into the resonator, thereby reducing the influence of the coupling patch radiation on the radiation characteristics of the main patch.

[0024] This embodiment is a differential decoupling antenna with a center frequency of 3.43 GHz. The substrate material used is Rogers RO4003C, with a dielectric constant of 3.55 and a loss angle of 0.0027. The length and width of metal patches 11 and 12 are both 0.25λ0. The edge-to-edge spacing between the two metal patches is 0.025λ0, and the center-to-center spacing is 0.27λ0. The center-to-center spacing of the feed points of the two coaxial probes on the same metal patch is 0.053λ0, where λ0 is the free-space wavelength corresponding to the center frequency. The overall length of the step impedance metal strip 13 (… y The axis is 0.27λ0, and the length of the middle part is ( y The axis is 0.14λ0, and the width of the middle part is ( x The axis is 0.014λ0. The length of the uniform impedance metal strip 14 ( y The axis is 0.51λ0, and the width is ( xThe S-parameters and gain simulation results of the antenna in this embodiment are as follows: (axis) = 0.015λ0. The side-to-side distance from the metal patches 11 and 12 to the widened portion of the stepped impedance metal strip 13 is 0.014λ0, and the side-to-side distance to the middle portion of the stepped impedance metal strip 13 is 0.027λ0. The side-to-side distance from the metal patches 11 and 12 to the uniform impedance metal strip 14 is 0.014λ0. Figure 4 , Figure 5 As shown, its 10-dB impedance matching bandwidth is 2.9%, its maximum gain in the operating frequency band is 4.97dB, and its isolation at 3.43GHz is greater than 18.31dB. Figure 6 This is the simulated radiation pattern of the E-plane at 3.43 GHz in this embodiment. The 3-dB beamwidth in the E-plane is 132.6°. At this frequency, the cross-polarization level within the 3-dB beamwidth of the E-plane is -8.72 dB.

[0025] Compared with existing differential patch antenna decoupling techniques, this invention optimizes the radiation pattern, improves radiation efficiency, and widens the beamwidth by 3dB by combining differential antenna decoupling techniques with step and uniform impedance resonators.

[0026] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A differential decoupling antenna combining a step resonator and a uniform impedance resonator, characterized in that, It includes a top metal layer, an intermediate dielectric substrate layer, and a bottom metal layer; The top metal layer consists of two parallel spaced metal patches, each of which is fed by two coaxial probes. The four coaxial probes are located on the same horizontal line. The top metal layer also includes a stepped impedance metal strip located outside the upper edges of the two metal patches, and a uniform impedance metal strip located outside the lower edges of the two metal patches; wherein, the stepped impedance metal strip is composed of widened portions at the left and right ends and a middle portion, the width of the widened portions at the left and right ends being twice the width of the middle portion; in the length direction, the left end of the stepped impedance metal strip is located between the feed points of the two coaxial probes of the left metal patch, and the right end is located between the feed points of the two coaxial probes of the right metal patch; in the length direction, the left end of the uniform impedance metal strip is located between the left edge of the left metal patch and the feed point of the leftmost coaxial probe, and the right end is located between the right edge of the right metal patch and the feed point of the rightmost coaxial probe; Two metal patches serve as the two radiating elements of the antenna. The stepped impedance metal strip and the impedance metal strip, together with the intermediate dielectric substrate layer and the bottom metal layer, respectively, form a stepped impedance resonator and a uniform impedance resonator, serving as a decoupling structure for the two radiating elements.

2. The differential decoupling antenna according to claim 1, characterized in that, The length and width of the two metal patches are both between 0.20λ0 and 0.25λ0. The edge-to-edge spacing of the two metal patches is between 0.020λ0 and 0.025λ0, and the center-to-center spacing is between 0.25λ0 and 0.30λ0. The center-to-center spacing of the feed points of the two coaxial probes on the same metal patch is between 0.050λ0 and 0.055λ0, where λ0 is the free space wavelength corresponding to the center frequency.

3. The differential decoupling antenna according to claim 2, characterized in that, The overall length of the stepped impedance metal strip is between 0.25λ0 and 0.30λ0, the length of the middle section is between 0.10λ0 and 0.15λ0, and the width of the middle section is between 0.010λ0 and 0.015λ0; the length of the uniform impedance metal strip is between 0.50λ0 and 0.55λ0, and the width is between 0.010λ0 and 0.015λ0.

4. The differential decoupling antenna according to claim 3, characterized in that, The edge-to-edge distance between the two metal patches and the widened portion of the stepped impedance metal strip is between 0.010λ0 and 0.015λ0, and the edge-to-edge distance between the two metal patches and the uniform impedance metal strip is between 0.010λ0 and 0.015λ0.

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