Double-frequency bidirectional radiation antenna with controllable frequency ratio

Abstract

The invention discloses a double-frequency bidirectional radiation antenna with a controllable frequency ratio. A U-shaped hole loaded back-to-back rectangular patch resonator and four columns of center hole loaded H-shaped high refractive index units are symmetrically distributed on two sides of the U-shaped hole loaded back-to-back rectangular patch resonator. Electromagnetic wave signals are fed into the back-to-back rectangular patch resonators loaded by the U-shaped holes through the metal probes, and are successively coupled to the H-shaped high refractive index units loaded by the left column and the right column of central holes. The characteristic that the dual-mode high-refractive-index frequency of the H-shaped high-refractive-index unit loaded by the center hole is independently regulated and controlled is utilized, and the vertical polarization dual-frequency working frequency of the back-to-back rectangular patch resonator loaded by the U-shaped hole is adjustable and controlled, so that the vertical polarization dual-frequency bidirectional radiation antenna with a controllable frequency ratio is realized, and gains on two frequency bands are enhanced.

Description

Technical Field

[0001] The present invention relates to a microwave communication device, and particularly to a dual - band bi - directional radiation antenna. Background Art

[0002] A dual - band bi - directional radiation antenna refers to an antenna whose beam can cover two symmetric and opposite regions and can operate in two frequency bands, which is beneficial for multi - mode operation in narrow communication scenarios such as tunnels, corridors, and highways. In a dual - band bi - directional radiation antenna, dual - band bi - directionality is a basic function. To improve the applicability of the antenna to different scenarios, the gain improvement of dual - band bi - directionality and the frequency ratio control of the two operating frequency bands become one of the important factors that need to be concerned. Therefore, designing a dual - band bi - directional radiation antenna with a controllable frequency ratio and improving its gain has high engineering and research value.

[0003] The currently reported dual - band bi - directional radiation antennas are mainly horizontally polarized and circularly polarized antennas, and there is no reported dual - band bi - directional radiation antenna that supports vertical polarization. The vertical - polarized bi - directional radiation antenna has better propagation characteristics and mainly operates in single - frequency mode at present. There are mainly two types: the first is to use a double - layer H - shaped metal patch loaded with four groups of vias to construct a pair of slot modes to achieve vertical - polarized bi - directional radiation; the second is to use a double - layer patch loaded with two groups of vias on the symmetry line to construct a slot mode and use the upper and lower layer patches to pull the slot mode to radiate to both sides to form vertical - polarized bi - directional radiation. Therefore, it is necessary to invent a dual - band bi - directional radiation antenna that supports vertical polarization, and the frequency ratio of the two operating frequency bands has a high degree of control freedom, and has the function of gain enhancement in both frequency bands. Summary of the Invention

[0004] Object of the Invention: Aiming at the above - mentioned prior art, a dual - band bi - directional radiation antenna with a controllable frequency ratio is proposed. The dual - band bi - directional radiation antenna supports vertical - polarization operation, has a high degree of adjustment freedom for the frequency ratio of the two frequency bands, and can enhance the gain in both frequency bands.

[0005] Technical Solution: A dual - band bi - directional radiation antenna with a controllable frequency ratio includes: a back - to - back rectangular patch resonator loaded with U - shaped holes, and four columns of H - shaped high - refractive - index units loaded with central holes are symmetrically distributed on both sides of the back - to - back rectangular patch resonator loaded with U - shaped holes; an electromagnetic wave signal is fed into the back - to - back rectangular patch resonator loaded with U - shaped holes through a metal probe and is successively coupled to two columns on the left and right of the H - shaped high - refractive - index units loaded with central holes; by using the characteristic of independent regulation of the dual - mode high - refractive - index frequencies of the H - shaped high - refractive - index units loaded with central holes and combining the controllability of the vertical - polarization dual - frequency operating frequencies of the back - to - back rectangular patch resonator loaded with U - shaped holes, a vertical - polarization dual - band bi - directional radiation antenna with a controllable frequency ratio is realized, and the gain in both frequency bands is enhanced.

[0006] Furthermore, the back-to-back rectangular patch resonator with U-shaped via loading consists of rectangular metal patches with circular grooves in the center on the upper and lower surfaces of the dielectric substrate and a pair of U-shaped arranged metallized vias spaced relatively apart; among them, the outer contours of the upper and lower rectangular metal patches are aligned, and the distance between the vertically arranged metallized vias on both sides of the U-shaped arranged metallized vias and the narrow side edges of the rectangular metal patches is between 0.07λ 01 -0.08λ 01 and the hole diameter is between 0.02λ 01 -0.03λ 01 ; the horizontally arranged metallized vias of the U-shaped arranged metallized vias are located at the wide side edges of the rectangular metal patches; in this structure, equivalent magnetic currents with longer electrical lengths are formed at the unperforated positions on both sides of the resonator, improving the gain and efficiency of the resonator's own radiation, and the corresponding frequency is controllable.

[0007] Furthermore, each of the H-shaped high refractive index units with central via loading consists of the same H-shaped metal strips on the upper and lower surfaces of the dielectric substrate and the metallized via three located in the center, and each unit operates in mode 1 with symmetrically distributed electric fields in the same direction and mode 2 with symmetrically distributed electric fields in the opposite direction; the diameter of the metallized via three has an independent control ability for the high refractive index frequency band corresponding to mode 1, and the notch length and width of the H-shaped metal strips have an independent control ability for the high refractive index frequency band corresponding to mode 2.

[0008] Furthermore, in the back-to-back rectangular patch resonator with U-shaped via loading, the operating frequency of mode 1 of the resonator is adjusted by changing the length of the unperforated area or the hole diameter of the vertically arranged metallized vias on both sides, and the operating frequencies of mode 1 and mode 2 are changed by changing the distance between the vertically arranged metallized vias on both sides and the narrow side of the rectangular patch, where mode 1 corresponds to the low-frequency resonance point and mode 2 corresponds to the high-frequency resonance point.

[0009] Furthermore, in the same column of the H-shaped high refractive index units with central via loading, the vertical spacing between units is between 0.03λ 01 -0.04λ 01 ; the distance between the inner H-shaped high refractive index unit with central via loading and the resonator is between 0.07λ 01 -0.09λ 01 ; the distance between the outer H-shaped high refractive index unit with central via loading and the resonator is between 0.46λ 01 -0.48λ 01 ; λ 01 is the air wavelength corresponding to the low frequency.

[0010] Beneficial effect: Existing dual-band bidirectional radiating antennas do not support vertical polarization, and bidirectional radiating antennas that support vertical polarization can only work in a single frequency band, and lack the freedom to control the adjustment of the frequency ratio of the two frequency bands, and do not have the gain enhancement function on the two frequency bands. The present invention symmetrically distributes four columns of H-shaped high-refractive index units loaded with central holes on both sides of the back-to-back rectangular patch resonators loaded with U-shaped holes, and utilizes the characteristics of independent regulation of the dual-mode high-refractive index frequency of the H-shaped high-refractive index units, combined with the adjustable vertical polarization dual-band working frequency of the back-to-back rectangular patch resonators loaded with U-shaped holes, to achieve a vertically polarized dual-band bidirectional radiating antenna with controllable frequency ratio, and can enhance the gain on the two frequency bands.

[0011] Specifically, the U-shaped hole loaded back-to-back rectangular patch resonator consists of upper and lower rectangular metal patches with circular grooves and a pair of U-shaped arranged metalized vias placed oppositely. The outer contours of the upper and lower rectangular metal patches are aligned, and the distance between the vertically arranged metalized vias of the U-shaped arranged metalized vias and the narrow edge of the rectangular metal patch is 0.07λ. 01 -0.08λ 01 Between, the hole diameter is 0.02λ 01 -0.03λ 01 The horizontally arranged metallized vias of the U-shaped arrangement are located at the wide edge of the rectangular metal patch. Under this structure, an equivalent magnetic flux with a longer electrical length is formed at the un-hole-added areas on both sides of the resonator, which can improve the gain and efficiency of the resonator's own radiation, and the corresponding frequency is controllable.

[0012] Each H-shaped high-refractive-index unit loaded in the center hole is composed of the same H-shaped metal strips in the upper and lower layers and a metallized via located in the center, and each unit operates in mode 1 with symmetrical electric field distribution in the same direction and mode 2 with symmetrical electric field distribution in the opposite direction. The diameter of metallized via three has independent control capability for the high-refractive-index frequency band corresponding to mode 1, and the notch length and width of the H-shaped metal strip have independent control capability for the high-refractive-index frequency band corresponding to mode 2. Therefore, the dual-band gain enhancement effect of the overall antenna has a high degree of control freedom.

[0013] Four rows of H-shaped high refractive index units are symmetrically placed on both sides of the back-to-back rectangular patch resonator loaded with U-shaped holes, and the upper and lower spacing of the units is 0.03λ 01 -0.04λ 01 The distance between the inner H-shaped high refractive index unit and the resonator is 0.07λ 01 -0.09λ 01 The distance between the outer H-shaped high refractive index unit and the resonator is 0.46λ 01 -0.48λ 01 At this time, better gain enhancement effect is obtained in both working frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic cross-sectional structure diagram of a dual-band bidirectional radiation antenna with a controllable frequency ratio according to the present invention;

[0015] Figure 2 This is a schematic top metal structure diagram of a dual-band bidirectional radiation antenna with a controllable frequency ratio according to the present invention;

[0016] Figure 3 This is a schematic bottom metal structure diagram of a dual-band bidirectional radiation antenna with a controllable frequency ratio according to the present invention;

[0017] Figure 4 This is the regulation ability of each parameter of the U-shaped hole-loaded back-to-back rectangular patch resonator in the dual-band bidirectional radiation antenna with a controllable frequency ratio according to the present invention on the resonance frequency. Among them, (a) is the influence of the length of the hole-free area of the vertically arranged holes on the resonance frequencies of the two modes, (b) is the influence of the diameter of the vertically arranged holes on the resonance frequencies of the two modes, and (c) is the influence of the distance from the vertically arranged holes to the narrow-side edge on the resonance frequencies of the two modes;

[0018] Figure 5 This is the regulation ability of each parameter of the H-shaped high refractive index unit in the dual-band bidirectional radiation antenna with a controllable frequency ratio according to the present invention on the high refractive index range. Among them, (a) is the influence of the diameter of the metallized via hole three on the transmission coefficient and the effective refractive index, (b) is the influence of the notch length on the transmission coefficient and the effective refractive index, and (c) is the influence of the notch width on the transmission coefficient and the effective refractive index;

[0019] Figure 6 These are the matching and gain simulation results of the antenna in the embodiment;

[0020] Figure 7 These are the E-plane pattern simulation results of the antenna in the embodiment and the antenna with only the U-shaped hole-loaded back-to-back rectangular patch resonator. Among them, (a) is the E-plane pattern at 3.49 GHz, and (b) is the E-plane pattern at 4.9 GHz. Detailed implementation manners

[0021] The following further explains the present invention with reference to the accompanying drawings.

[0022] As Figure 1 shown, a dual-band bidirectional radiation antenna with a controllable frequency ratio mainly consists of a top metal structure 1, a dielectric substrate 2, a bottom metal structure 3, a metallized via hole 4, and a metal probe 5.

[0023] As Figure 2As shown in the figure, the top-layer metal structure 1 is composed of a rectangular metal patch 101 with a circular ring groove 103 in the center, a metal ring 102, and four columns of H-shaped metal strips 104. The overall structure is located on the upper surface of the dielectric substrate 2 and is centered with the center of the dielectric substrate. The four columns of H-shaped metal strips 104 are symmetrically located on both sides of the rectangular metal patch 101. The length of the rectangular metal patch 101 is between 0.43λ 01 -0.44λ 01 and the width is between 0.35λ 01 -0.37λ 01 , where λ 01 is the air wavelength corresponding to the low frequency. The length of the H-shaped metal strip 104 is between 0.15λ 01 -0.17λ 01 , the notch length of the H-shaped metal strip is between 0.04λ 01 -0.05λ 01 , and the width is between 0.01λ 01 -0.02λ 01 . The H-shaped metal strips 104 are evenly arranged, and the spacing between the strips in the same column is between 0.03λ 01 -0.04λ 01 . The distance between the H-shaped metal strip 104 closer to the rectangular metal patch 101 and the narrow-edge of the rectangular metal patch 101 is between 0.07λ 01 -0.09λ 01 , and the distance between the H-shaped metal strip 104 farther from the rectangular metal patch 101 and the narrow-edge of the rectangular metal patch 101 is between 0.46λ 01 -0.48λ 01 . The metal ring 102 is located in the circular ring groove 103 and they are concentrically arranged.

[0024] As Figure 3 shown, the bottom-layer metal structure 3 is composed of a rectangular metal patch 301 with a circular ring groove 302 in the center and four columns of H-shaped metal strips 303. The overall structure is located on the lower surface of the dielectric substrate 2 and is aligned with the top-layer metal structure.

[0025] The metallized vias 4 are composed of metallized via one 401, metallized via two 402, metallized via three 403, and metallized via four 404. A row of horizontally arranged metallized vias one 401 and two columns of vertically arranged metallized vias two 402 form a U-shaped metallized via. The U-shaped metallized via connects the bottom-layer rectangular metal patch 301 and the top-layer rectangular metal patch 101. Among them, the horizontally arranged metallized vias one 401 are located at the wide-edge of the rectangular metal patch 101, and the two U-shaped metallized vias are arranged at intervals relative to each other. The distance between the two columns of vertically arranged metallized vias two 402 and the corresponding narrow-edge of the rectangular metal patch 101 is between 0.07λ 01-0.08λ 01 The diameter of the metallized via 402 is between 0.02λ 01 -0.03λ 01 The metallized via hole 303 connects the bottom H-shaped metal strip 303 and the top H-shaped metal strip 104 at the same position and is located at the center of the H-shaped metal strip. The diameter of the metallized via hole 303 is 0.002λ. 01 -0.003λ 01 The metal probe 5 passes through the metallized via hole 404 and is connected to the top metal ring 102.

[0026] A rectangular metal patch 101 with a circular groove 103 in the center of the top layer, a dielectric substrate 2, a rectangular metal patch 301 with a circular groove 302 in the center of the bottom layer, a metallized via 1 401, and a metallized via 2 402 form a back-to-back rectangular patch resonator loaded with a U-shaped hole. A top H-shaped metal strip 104, a dielectric substrate 2, a bottom H-shaped metal strip 303, and a metallized via 3 403 form four rows of central hole-loaded H-shaped high-refractive-index units.

[0027] For the frequency ratio controllable dual-frequency bidirectional radiation antenna of the present invention, the electromagnetic wave signal is fed into the back-to-back rectangular patch resonator loaded with the U-shaped hole through a metal probe, and is successively coupled to the two columns of H-shaped high refractive index units on the left and right. Under the joint action of the overall structure, dual-frequency vertically polarized bidirectional radiation with controllable frequency ratio is realized.

[0028] In this process, the back-to-back rectangular patch resonator loaded with U-shaped holes can work in the form of mode one and mode two. Mode one corresponds to the low-frequency resonance point, the internal electric field is a vertical electric field with uniform distribution in the same direction, and there are equivalent magnetic currents on the left and right sides of the resonator without holes. The effective increase in the electrical length of the magnetic current can improve the gain and efficiency of the antenna; Mode two corresponds to the high-frequency resonance point, which presents a full-wave distribution as a whole, but there are also long equivalent magnetic currents on the left and right sides and the upper and lower sides of the resonator without holes, which are used to support the basic vertical polarization horizontal two-way radiation. The operating frequency of mode one can be adjusted by changing the length of the hole-free area or the hole diameter of the vertically arranged metalized vias. The operating frequencies of modes one and two can be changed by changing the distance between the vertically arranged metalized vias and the narrow side of the rectangular patch, thereby providing a basis for adjusting the frequency ratio of the two working frequency bands of the antenna.

[0029] The four-column H-shaped high refractive index unit receives the vertically polarized signal coupled from the U-shaped hole-loaded back-to-back rectangular patch resonator, exciting two modes of the H-shaped high refractive index unit. Mode 1 operates in the low-frequency band. Its electric field is mainly perpendicular to the upper and lower H-shaped metal strips, symmetrically distributed on the left and right sides with the same direction. The amplitude is zero at the maximum vias on both sides. At this time, a high refractive index region that can cover the frequency of mode 1 of the U-shaped hole-loaded back-to-back rectangular patch resonator can be extracted, thereby achieving the effect of gain enhancement; and the frequency of this effective high refractive index region can be adjusted with the change of the diameter of the third metallized via. Mode 2 operates in the high-frequency band. The electric field is also perpendicular to the upper and lower H-shaped metal strips, symmetrically distributed on the left and right sides with opposite directions. The amplitude is the largest on both sides and zero on the extension line of the horizontal center symmetry line. The upper and lower surface currents present a co-directional half-wave distribution on the upper and lower edges and the notch edges as a whole. At this time, a high refractive index region that can cover the frequency of mode 2 of the U-shaped hole-loaded back-to-back rectangular patch resonator can be extracted, thereby achieving the effect of gain enhancement; and changing the length or width of the notch can change the frequency of this effective high refractive index region. Therefore, the H-shaped high refractive index unit can support vertical polarization dual-frequency operation, enhance the gain of bidirectional radiation, and has the characteristic of independent regulation of dual-frequency operating frequencies.

[0030] Considering the signal coupling strength on the H-shaped high refractive index unit and the uniformity of the field between the units comprehensively, the distance between the two inner columns of H-shaped high refractive index units and the U-shaped hole-loaded back-to-back rectangular patch resonator is 0.07λ 01 -0.09λ 01 When it is between, the effect of gain enhancement is better. The distance between the two outer columns of H-shaped high refractive index units and the inner H-shaped high refractive index units needs to comprehensively consider the gain enhancement effects in the low-frequency band and the high-frequency short band. When the distance is between 0.46λ 01 -0.48λ 01 When it is between, there are good gain enhancement effects in both high and low operating frequency bands.

[0031] Compared with the prior art, the present invention can support dual-frequency bidirectional radiation of vertical polarization, and has the advantages of high degree of freedom in frequency ratio adjustment and dual-band gain enhancement. A design case of the present invention is listed below, and its schematic diagram of the antenna structure is as shown in Figures 1 to 3 The dielectric substrate used in the design of this embodiment is RO4003C, and the electrical size of the antenna is 1.7λ 01 ×0.49λ 01 The cross-section is only 0.018λ 01 . Figure 4 The regulation ability of each parameter of the U-shaped hole-loaded back-to-back rectangular patch resonator on the resonant frequency is given. From Figure 4In (a) and (b), the length of the hole-free region of the vertically arranged holes or their hole diameters can independently regulate the resonance frequency of Mode 1. The larger the length of the hole-free region or the smaller the diameter of the vertically arranged holes, the lower the resonance frequency of Mode 1, and the resonance frequency of Mode 2 changes little. Figure 4 In (c), it shows the influence of the distance from the vertically arranged holes to the narrow-side edge on the resonance frequencies of the two modes. As the distance increases, the resonance frequency of Mode 1 decreases, and the resonance frequency of Mode 2 increases. Figure 5 It gives the regulation ability of each parameter of the H-shaped high refractive index unit on the high refractive index interval. From Figure 5 In (a), it can be seen that the diameter of the metallized via 3 can independently regulate the coverage of the low-frequency high refractive index interval, and the larger the diameter, the higher the high refractive index interval corresponding to the low-frequency band moves to the high frequency. From Figure 5 In (b) and (c), it can be seen that the notch length and width can independently regulate the coverage of the high-frequency high refractive index interval, and the longer the notch length or the wider the notch width, the higher the high refractive index interval corresponding to the high-frequency band moves to the low frequency.

[0032] Figure 6 It gives the matching and gain simulation results of this embodiment. As Figure 6 shown, this embodiment realizes dual-band operation, where the low-frequency operating band covers 3.478 GHz to 3.497 GHz, the relative bandwidth is 0.5%, and the maximum gain is 3.44 dBi; the high-frequency operating band covers 4.885 GHz to 4.91 GHz, the relative bandwidth is 0.5%, and the maximum gain is 6.42 dBi. Figure 7 It compares the simulation results of the E-plane radiation pattern of this embodiment with that of the antenna with only U-shaped hole-loaded back-to-back rectangular patch resonators. From Figure 7 it can be known that compared with the antenna with only U-shaped hole-loaded back-to-back rectangular patch resonators, this embodiment realizes the gain enhancement effect in both frequency bands. Combining the high degree of freedom of frequency regulation of the above two resonances, a dual-band bidirectional radiation antenna with a controllable frequency ratio is realized, and there is an effect of gain enhancement.

[0033] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A dual - frequency bi - directional radiation antenna with controllable frequency ratio, characterized in that, include: A back-to-back rectangular patch resonator loaded with a U-shaped hole, and four columns of H-shaped high-refractive-index units loaded with a center hole are symmetrically distributed on both sides of the back-to-back rectangular patch resonator loaded with the U-shaped hole; an electromagnetic wave signal is fed into the back-to-back rectangular patch resonator loaded with the U-shaped hole through a metal probe, and is successively coupled to the two left and right columns of H-shaped high-refractive-index units loaded with the center hole; utilizing the independent controllable dual-mode high-refractive-index frequency characteristics of the H-shaped high-refractive-index units loaded with the center hole, combined with the adjustable vertically polarized dual-frequency operating frequency of the back-to-back rectangular patch resonator loaded with the U-shaped hole, a vertically polarized dual-frequency bidirectional radiating antenna with controllable frequency ratio is realized, and the gain on the two frequency bands is enhanced.

2. The dual - frequency bi - directional radiation antenna with controllable frequency ratio according to claim 1, characterized in that, The back-to-back rectangular patch resonator with U-shaped via loading includes a rectangular metal patch with an annular groove in the center on the upper and lower surfaces of a dielectric substrate and a pair of U-shaped arranged metallized vias spaced relatively apart; wherein, the outer contours of the upper and lower rectangular metal patches are aligned, and the distance between the vertically arranged metallized vias on both sides of the U-shaped arranged metallized vias and the narrow side edge of the rectangular metal patch is within 0.07λ 01 -0.08λ 01 and the hole diameter is within 0.02λ 01 -0.03λ 01 ; the horizontally arranged metallized vias of the U-shaped arranged metallized vias are located at the wide side edge of the rectangular metal patch; under this structure, equivalent magnetic currents with a long electrical length are formed at the unperforated positions on both sides of the resonator, improving the gain and efficiency of the self-radiation of the resonator, and the corresponding frequency is controllable.

3. The dual - frequency bi - directional radiation antenna with controllable frequency ratio according to claim 1, characterized in that, Each H-shaped high refractive index unit loaded by the center hole includes the same H-shaped metal strips located on the upper and lower surfaces of the dielectric substrate and a metallized via three located in the center, and each unit has a mode 1 with symmetrical electric field distribution in the same direction and a mode 2 with symmetrical electric field distribution in the opposite direction, mode 1 works in a low frequency band, and mode 2 works in a high frequency band; the diameter of the metallized via three has independent control capabilities for the high refractive index frequency band corresponding to mode 1, and the notch length and width of the H-shaped metal strip have independent control capabilities for the high refractive index frequency band corresponding to mode 2.

4. The dual - frequency bi - directional radiation antenna with controllable frequency ratio according to claim 2, characterized in that, In the back-to-back rectangular patch resonator loaded with the U-shaped hole, the operating frequency of the resonator mode one is adjusted by changing the length of the hole-free area or the hole diameter of the vertically arranged metalized vias on both sides, and the operating frequencies of mode one and mode two are changed by changing the distance between the vertically arranged metalized vias on both sides and the narrow side of the rectangular patch, wherein mode one corresponds to a low-frequency resonance point and mode two corresponds to a high-frequency resonance point.

5. The dual - frequency bi - directional radiation antenna with controllable frequency ratio according to claim 3, characterized in that, Among the H-shaped high refractive index units loaded with the central holes in the same column, the vertical distance between the units is between 0.03λ 01 -0.04λ 01 The distance between the H-shaped high refractive index unit loaded with the inner central hole and the resonator is between 0.07λ 01 -0.09λ 01 The distance between the H-shaped high refractive index unit loaded with the outer central hole and the resonator is between 0.46λ 01 -0.48λ 01 where λ 01 is the air wavelength corresponding to the low frequency.

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