1-bit reconfigurable low-power reflective array antenna applied to b5g communication

Abstract

A 1-bit reconfigurable low-power reflection array antenna applied to B5G communication, characterized in that it comprises a reflection array and a feed source, the reflection array comprises a plurality of periodically arranged reflection units, the reflection unit comprises a patch, an upper ground plate and a lower ground plate arranged from top to bottom; the upper ground plate is etched with a short-circuit groove, a pad is arranged in the short-circuit groove, a PIN diode is arranged between one side of the pad and one side of the short-circuit groove, and a capacitor is arranged between the other side of the pad and the other side of the short-circuit groove; the pad is connected with a direct current bias line, by controlling the conduction and disconnection of the PIN diode, two compensation phase states of 0° and 180° are obtained, and the 1-bit reconfigurable performance is realized. The antenna structure is simple, the current flowing through the active device is reduced to reduce the system power consumption, at the same time, the antenna realizes high aperture efficiency and relatively accurate beam scanning angle.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antenna design in wireless communication technology, and particularly relates to a 1-bit reconfigurable low-power reflection array antenna applied to B5G communication. BACKGROUND

[0002] In recent years, the related technology of the fifth generation mobile communication (5th Generation Mobile Communication, 5G) has become mature, in order to realize higher speed and larger capacity of data transmission rate, the academic and industrial circles have begun to study the beyond 5th generation mobile communication (Beyond 5G, B5G) technology. With the promotion of B5G mobile communication to the application of reconfigurable intelligent super surface (Intelligent Reflecting Surface, RIS), the reconfigurable reflection array antenna has been widely concerned. The reconfigurable reflection array antenna can quickly, conveniently and accurately realize the beam scanning performance by loading PIN diode, varactor diode, MEMS switch and other devices in each unit to dynamically adjust the reflection phase of each unit. In addition, due to the large spatial attenuation of high-frequency electromagnetic signals, more base stations need to be deployed to achieve good signal coverage. The increase in the number of base stations means the increase in power supply cost. In order to alleviate the power supply pressure, it is necessary to design a low-power reflection array antenna with beam scanning performance.

[0003] Through the literature and patent retrieval of the prior art, it is found that there are currently two main methods to realize the low-power performance of the reflection array antenna. The first method is to reduce the number of active devices, for example, two adjacent units form a subarray, and share one active device. The disadvantage of this method is that the switchable beam state is limited. The second method is to select low-loss reconfigurable devices, but considering the limitation factors such as antenna operating frequency, the type of available devices is often limited. SUMMARY

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a 1-bit reconfigurable low-power reconfigurable reflection array antenna applied to B5G mobile terminal, which has simple antenna structure, reduces the current flowing through the active device to reduce the system power consumption, and at the same time, the antenna realizes higher aperture efficiency and more accurate beam scanning angle.

[0005] The active device reduces the current flowing through the active device to reduce the system power consumption, and at the same time, the antenna realizes higher aperture efficiency and more accurate beam scanning angle.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is:

[0007] The application discloses a 1-bit reconfigurable low-power reflectarray antenna applied to B5G communication, which comprises a reflectarray and a feed source, the reflectarray comprises a plurality of periodically arranged reflecting units, the reflecting unit comprises a patch, an upper ground plate and a lower ground plate arranged from top to bottom, the upper ground plate is etched with a short-circuit groove, a pad is arranged in the short-circuit groove, a PIN diode is arranged between one side of the pad and one side of the short-circuit groove, and a capacitor is arranged between the other side of the pad and the other side of the short-circuit groove, the pad is connected with a direct-current bias line, and by controlling the conduction and disconnection of the PIN diode, two compensation phase states of 0° and 180° are obtained, and the 1-bit reconfigurable performance is realized.

[0008] In one embodiment, the short-circuit groove is a rectangular groove, and the one side and the other side of the short-circuit groove are symmetrical long side sides.

[0009] In one embodiment, the lower surface of the intermediate dielectric plate is printed with a phase delay line, the length of the short-circuit groove is 0.2 lambda 0, and the length of the phase delay line is 0.14 lambda 0, wherein lambda 0 is the free space wavelength corresponding to the center frequency of the antenna.

[0010] In one embodiment, the patch is printed on the upper surface of the upper dielectric plate, the upper ground plate is printed on the upper surface of the intermediate dielectric plate, and the lower ground plate is printed on the upper surface of the lower dielectric plate, the upper dielectric plate and the intermediate dielectric plate are connected through an upper air layer, and the intermediate dielectric plate and the lower dielectric plate are connected through a lower air layer.

[0011] In one embodiment, the direct-current bias line is printed on the lower surface of the intermediate dielectric plate and connected with the pad through a short-circuit column penetrating the intermediate dielectric plate.

[0012] In one embodiment, the anode of the PIN diode is welded on the pad, high and low levels are provided for the direct-current bias line, the on-off of the PIN diode is controlled, and thus the reconfigurable performance of the unit is realized.

[0013] In one embodiment, the direct-current bias line comprises a bias line and a fan-shaped open-circuit stub with a radius of one-quarter wavelength, and the fan-shaped open-circuit stub is connected to the bias line.

[0014] In one embodiment, the patch is square-shaped, and the short-circuit groove is located directly below the center of the patch.

[0015] In one embodiment, the feed source adopts a standard gain horn antenna, and the polarization direction is parallel to the length direction of the phase delay line.

[0016] Compared with the prior art, the application has the following beneficial effects:

[0017] 1) The application reduces the current flowing through the PIN diode in the on state, so that the array gain does not decrease significantly when the PIN diode works in a low-power state, thereby achieving higher aperture efficiency while the antenna reflection loss is low.

[0018] 2) The antenna can work normally at very low power consumption and maintain good radiation performance.

[0019] Figure 1 is a structural schematic diagram of the reflective array antenna in the specific embodiment.

[0020] Figure 2 is a three-dimensional structural exploded view of the antenna unit in the specific embodiment.

[0021] Figure 3 is a side view of the antenna unit in the specific embodiment.

[0022] Figure 4 is a top view of the middle layer floor of the antenna unit in the specific embodiment.

[0023] Figure 5 is a simulation result of the amplitude and phase of the reflective unit in the specific embodiment.

[0024] Figure 6 is a simulation and measured beam scanning pattern of the H plane of the 1-bit reconfigurable reflective array antenna in the specific embodiment.

[0025] Figure 7 is a simulation and measured beam scanning pattern of the E plane of the 1-bit reconfigurable reflective array antenna in the specific embodiment.

[0026] Figure 8 is a curve of the gain and corresponding aperture efficiency of the 1-bit reconfigurable reflective array antenna at 0° emission versus frequency in the specific embodiment.

[0027] Figure 9 is the antenna gain when the equivalent resistance of the PIN diode in the 1-bit reconfigurable reflective array antenna takes different values in the specific embodiment. DETAILED DESCRIPTION

[0028] The embodiments of the application will be described in detail below with reference to the accompanying drawings and examples.

[0029] A 1-bit reconfigurable low-power reflective array antenna applied to B5G communication, including a reflective array 1 and a feed source 2, and the structure is shown in Figure 1. The reflective array 1 includes a plurality of periodically arranged reflective units, and the number of reflective units is represented by MxN in the application. The reflective array 1 can also be composed of only MxN reflective units, wherein M and N are integers greater than 2.

[0030] M and N are integers greater than 2.

[0031] Referring to FIG. 2, FIG. 3 and FIG. 4, the reflection unit of the present application comprises a patch 111, an upper ground plate 112 and a lower ground plate 117 arranged from top to bottom. Among them, a short-circuit groove 118 is etched on the upper ground plate 112, and a pad 113 is arranged at the groove position of the short-circuit groove 118, a PIN diode 1114 is arranged between one side of the pad 113 and one side of the short-circuit groove 118, and a capacitor 1115 is arranged between the other side of the pad 113 and the other side of the short-circuit groove 118. That is, between the opposite sides of the short-circuit groove 118, the connection is made through the capacitor 1115-pad 113-PIN diode 1114, and the pad 113 is connected with the direct current biasing straight line 116.

[0032] According to the above structure, the technical scheme of the present application is realized as follows:

[0033] When the PIN diode 1114 is turned on, the short-circuit groove 118 is short-circuited, and the upper ground plate 112 serves as a reflection plate. When the PIN diode 1114 is turned off, the upper ground plate 112 is a gap ground plate, and the electromagnetic wave is coupled to the phase delay line 115 via the short-circuit groove 118 to realize reflection phase control. The phase delay line 115 can be printed on the lower surface of the dielectric substrate 1110 or other areas that can facilitate coupling with the short-circuit groove 118, and its function is to adjust the phase of the reflected electromagnetic wave, so as to obtain the expected unit reflection phase. Therefore, for the reflection unit, the 1-bit reconfigurable performance of the reflection unit is realized by turning on and turning off the PIN diode 1114. Its working principle can be explained more specifically as follows: when the PIN diode 1114 is turned on, the short-circuit groove 118 is connected, and the electromagnetic wave received by the patch 111 is directly reflected by the upper ground plate 112, and then radiated back to the free space by the patch 111; when the PIN diode 1114 is turned off, the electromagnetic wave received by the patch 111 is coupled to the phase delay line 115 via the short-circuit groove 118, and is reflected by the open end of the phase delay line 115, coupled to the patch 111 and radiated back to the free space. The difference between the reflection phases in the two states is about 180°, realizing the 1-bit reconfigurable performance. The capacitor 1115 plays a role of isolating direct current and preventing the PIN diode 1114 from being short-circuited.

[0034] When electromagnetic waves emitted by feed 2 illuminate different reflective elements in reflective array 1, a phase delay difference is formed due to the different propagation paths of the electromagnetic waves. To obtain a radiation beam in a specific direction, each element in array 1 should have a specific phase distribution. To achieve this phase distribution, different phase compensations should be applied to each element. In a 1-bit reconfigurable reflective array, the compensation phase is quantized into two phase states: 0° and 180°, corresponding to the conduction and disconnection of PIN diode 1114 in element 11. By controlling the on / off state of PIN diode 1114 through a DC control circuit, array 11 forms a specific phase distribution, thus achieving a specific angle of reflection.

[0035] Wave beam.

[0036] The equivalent circuit of a PIN diode in its on-state includes resistance. The higher the resistance, the greater the loss of the reflecting element and the lower the aperture efficiency of the reflector array antenna. The operating characteristics of the PIN diode 1114 in its on-state are as follows: as the forward voltage applied across the PIN diode 1114 increases, the diode's on-current increases, and its equivalent resistance decreases accordingly. The PIN diode 1114 described in this invention is soldered at the center of a gap where the current is relatively low. Even if the on-current of the PIN diode 1114 is reduced, increasing its equivalent resistance, the energy consumed by the equivalent resistance remains low because the current flowing through the PIN diode 1114 is small. Therefore, the loss of the reflecting element does not increase significantly with the increase of the equivalent resistance of the PIN diode 1114. Thus, when both the on-voltage and current of the PIN diode 1114 are reduced, i.e., when the PIN diode 1114 operates in a low-power state, the antenna's radiation performance is not significantly affected.

[0037] In an embodiment of the present invention, the patch 111 is square in shape, and the short-circuit slot 118 is located directly below the center of the patch 111. The short-circuit slot 118 is a rectangular slot, and one side and the other side of the short-circuit slot 118 are its symmetrical long sides, that is, the capacitor 1115-pad 113-PIN diode 1114 are connected between the two long sides of the short-circuit slot 118, and the short-circuit slot 118 can be perpendicular to the length direction of the phase delay line 115. The length of the short-circuit slot 118 is approximately 0.2λ0, and the length of the phase delay line 115 is approximately 0.14λ0, where λ0 is the free-space wavelength corresponding to the antenna center frequency. This limitation further optimizes the electromagnetic wave reflection and radiation effect.

[0038] In an embodiment of the present application, the patch 111 is printed on the upper surface of the upper dielectric plate 119, the upper ground plate 112 is printed on the upper surface of the middle dielectric plate 1110, and the lower ground plate 117 is printed on the upper surface of the lower dielectric plate 1111. The upper dielectric plate 119, the middle dielectric plate 1110, and the lower dielectric plate 1111 have equal areas.

[0039] The design of the upper air layer 1112 and the lower air layer 1113 in the embodiment can improve the unit bandwidth and increase the adjustment freedom. The lower ground plate 117 acts as a reflecting plate and can reflect incident electromagnetic waves.

[0040] In an embodiment of the present application, the DC bias line 116 is printed on the lower surface of the middle dielectric plate 1110 and connected to the solder pad 113 through the shorting post 114 penetrating the middle dielectric plate 1110. Specifically, one end of the DC bias line 116 is connected to the solder pad 113 through the shorting post 114, and the anode of the PIN diode 1114 is welded on the solder pad 113 to provide high and low levels for the DC bias line 116, that is, to control the on-off of the PIN diode 1114, thereby realizing the reconfigurable performance of the unit.

[0041] The DC bias line 116 is connected to the solder pad 113 through the shorting post 114, and the anode of the PIN diode 1114 is welded on the solder pad 113 to provide high and low levels for the DC bias line 116, that is, to control the on-off of the PIN diode 1114, thereby realizing the reconfigurable performance of the unit. One structure of the DC bias line 116 is shown in FIG. 3, which includes a bias line and a fan-shaped open-circuit stub with a radius of one-quarter wavelength, and the fan-shaped open-circuit stub is connected to the bias line.

[0042] In a specific embodiment of the present application, the center operating frequency of the antenna is selected as 5.4 GHz, which belongs to the B5G mobile communication operating frequency band. M=N=14, that is, the reflective array 1 is composed of 14x14 periodic arrangement of reflective units. The size of the reflective unit is 25mm, which is about λg(wavelength in medium) / 2. The patch 111 is a square patch with a side length of 17.5mm. The length of the short-circuit slot 118 on the ground plate 112 is 11mm, and the width is 2mm. The length of the phase delay line 115 is 8mm, and the width is 1mm. The dielectric constant of the dielectric plate 119 and the dielectric plate 1110 is F4B material with a dielectric constant of 2.65, the dielectric constant of the dielectric plate 1111 is FR4 material with a dielectric constant of 4.4, and the thickness of the three-layer dielectric plate is 1mm. The thicknesses of the air layer 1112 and the air layer 1113 are both 2mm. The feed 2 adopts a standard gain horn antenna, and the polarization direction is parallel to the length direction of the phase delay line 115.

[0043] Figure 5 is the reflection coefficient amplitude and the reflection phase difference of the reflection unit under the on and off of the PIN diode 1114. The two states of the 1-bit reconfigurable reflective array unit achieve a phase difference of 180°±20° in the frequency band of 4.9-5.7 GHz, and a relative phase bandwidth of about 15.1%. In the frequency band of 4.8-6.0 GHz, the reflection loss of the unit is always less than 0.1 dB under the on and off of the PIN diode.

[0044] Figure 6 is the H-plane simulation and measured beam scanning results of the 1-bit reconfigurable reflective array antenna at 5.4 GHz. The antenna achieves a beam scanning of ±50°.

[0045] Figure 7 is the E-plane simulation and measured beam scanning results of the 1-bit reconfigurable reflective array antenna at 5.4 GHz. Due to the symmetry, only the 0°-50° beam scanning angle needs to be observed since the feed 2 is not in this plane. At 5.4 GHz, the highest gain of the 1-bit reconfigurable reflective array antenna is 22.4 dBi, and the peak aperture efficiency is 34.8%.

[0046] Figure 8 is the gain and the corresponding aperture efficiency of the 1-bit reconfigurable reflective array antenna at 0° exit as a function of frequency. In the frequency band of 4.9-5.7 GHz, the aperture efficiency of the antenna is higher than 20%, and a relatively stable high aperture efficiency performance is achieved in a wide frequency band.

[0047] In the frequency band of 4.9-5.7 GHz, the gain fluctuation of the 0° exit beam is always maintained within 3 dB.

[0048] Figure 9 is the antenna gain when the equivalent resistance of the PIN diode in the 1-bit reconfigurable reflective array antenna takes different values. The SMP1340-079LF model PIN diode is selected in the application. When the rated current 10mA is turned on, the equivalent resistance of the diode is about 0.85Ω, and when the current is reduced to 0.03mA, the equivalent resistance of the diode is about 9Ω. When the equivalent resistance increases from 0.85Ω to 9Ω, the power consumption of a single PIN diode decreases from 8.5mW to 0.021mW. For the 0° exit beam, there are a total of 90 PIN diodes in the array in the on state, and the total power consumption of the PIN diodes decreases from 765mW to 1.89mW, and the array gain decreases from 20.7dBi to 21.1dBi, only by 0.5dB. Therefore, the 1-bit reconfigurable reflective array antenna can maintain good radiation performance in a low power consumption state.

[0049] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application in any form. Any equivalent changes and modifications made within the scope of the present application claims should be covered by the present application claims.

Claims

1. A 1-bit reconfigurable low-power reflective array antenna applied to B5G communication, characterized in that, The application relates to a reflectarray (1) and a feed source (2), the reflectarray (1) comprising a plurality of periodically arranged reflecting units, the reflecting units comprising, from top to bottom, a patch (111), an upper ground plate (112) and a lower ground plate (117); the upper ground plate (112) is etched with a short-circuit groove (118), a pad (113) is arranged in the short-circuit groove (118), a PIN diode (1114) is arranged between one side of the pad (113) and one side of the short-circuit groove (118), a capacitor (1115) is arranged between the other side of the pad (113) and the other side of the short-circuit groove (118), and the pad (113) is connected with a direct-current bias line (116); by controlling the conduction and disconnection of the PIN diode (1114), two compensation phase states of 0 and 180 degrees are obtained, and 1-bit reconfigurable performance is realized; when the PIN diode (1114) is turned on, the short-circuit groove (118) is short-circuited, and the upper ground plate (112) serves as a reflecting plate; when the PIN diode (1114) is turned off, the upper ground plate (112) is a slot ground plate, electromagnetic waves are coupled to a phase delay line (115) through the short-circuit groove (118), and reflection phase regulation is realized. The short-circuit groove (118) is a rectangular groove, and one side and the other side of the short-circuit groove (118) are symmetrical long sides; the length direction of the short-circuit groove (118) is perpendicular to the length direction of the phase delay line (115). The patch (111) is printed on the upper surface of an upper dielectric plate (119), the upper ground plate (112) is printed on the upper surface of a middle dielectric plate (1110), the lower ground plate (117) is printed on the upper surface of a lower dielectric plate (1111), the upper dielectric plate (119) and the middle dielectric plate (1110) are connected through an upper air layer (1112), the middle dielectric plate (1110) and the lower dielectric plate (1111) are connected through a lower air layer (1113), and the phase delay line (115) is printed on the lower surface of the middle dielectric plate (1110).

2. The 1-bit reconfigurable low-profile metasurface antenna for B5G communications of claim 1, wherein, The length of the short-circuit groove (118) is 0.2 lambda0, and the length of the phase delay line (115) is 0.14 lambda0, wherein lambda0 is the free space wavelength corresponding to the center frequency of the antenna. 3.The 1-bit reconfigurable low-profile metasurface antenna applied to B5G communications of claim 1, wherein, The direct-current bias line (116) is printed on the lower surface of the middle dielectric plate (1110) and connected with the pad (113) through a short-circuit column (114) penetrating the middle dielectric plate (1110).

4. The 1-bit reconfigurable low-power reflectarray antenna for B5G communications of claim 1 or 3, wherein, The anode of the PIN diode (1114) is welded on the pad (113) to provide high and low levels for the direct-current bias line (116) and control the conduction and disconnection of the PIN diode (1114), thereby realizing the reconfigurable performance of the unit.

5. The 1-bit reconfigurable low-profile metasurface antenna for B5G communications of claim 4, wherein, The direct-current bias line (116) comprises a bias line and a fan-shaped open stub with a radius of one quarter of a wavelength, and the fan-shaped open stub is connected to the bias line.

6. The 1-bit reconfigurable low-profile metasurface antenna for B5G communications of claim 1, wherein, The patch (111) is square-shaped, and the short-circuit groove (118) is located directly below the center of the patch (111).

7. The 1-bit reconfigurable low-profile metasurface antenna for B5G communications of claim 1, wherein, The feed source (2) adopts a standard gain horn antenna, and the polarization direction is parallel to the length direction of the phase delay line (115).

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