Antenna Array

Abstract

The present application relates to an antenna array, which includes at least one antenna module, wherein the antenna module includes an antenna substrate, a first slot antenna and a second slot antenna; the first slot antenna and the second slot antenna are located on the antenna substrate, the first slot antenna and the second slot antenna share the same slot, and the working mode of the first slot antenna is orthogonal to the working mode of the second slot antenna. The present application achieves mode diversity of the two slot antennas by setting the working modes of the two slot antennas of the antenna module in the antenna array to be orthogonal, thereby improving the isolation between the two slot antennas in the same antenna module and ensuring the radiation performance of the antenna array.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to an antenna array. Background Art

[0002] As the communications industry enters the 5G era, massive MIMO technology has been widely used in various communications devices. Due to the small size of mobile communications devices (especially smartphones), in order to ensure high isolation between antennas, the antenna array of mobile communications devices usually adopts a 4*4 MIMO array. However, as the communication rate is further improved today, a 4-unit antenna array (i.e., a 4*4 MIMO array) is difficult to meet communication needs. At this time, a monopole antenna is usually used to increase the scale of the antenna array to meet communication needs. Among them, the antenna array increased by the use of a monopole antenna may be an 8*8 MIMO array, or a larger MIMO array, such as a 10*10 MIMO array, a 12*12 MIMO array, or even a 16*16 MIMO array. Taking smartphones as an example, monopole antennas usually need to be placed perpendicular to the substrate and arranged along the side walls of the smartphone. In other words, the use of monopole antennas will have a greater impact on the thickness of smartphones, which is not conducive to the thin and light design of smartphones. In contrast, array antennas based on slot radiation usually rely on slots etched on the substrate to achieve radiation and do not take up additional internal space of the smartphone. Therefore, the use of slot antennas can effectively reduce the impact of the antenna on the thickness of the smartphone, which is conducive to the lightweight design of the smartphone.

[0003] In the prior art, slot antennas usually rely on spatial diversity to improve the isolation between antennas. However, as the size of antennas increases, the area available for isolation between antennas becomes smaller and smaller, and the isolation between antennas becomes lower and lower, resulting in reduced radiation performance of the entire antenna array. Summary of the invention

[0004] The present application provides an antenna module to solve the problem that the area used for isolation between antennas becomes smaller and smaller due to the expansion of antenna scale, thereby reducing the isolation between antennas and causing the radiation performance of the antenna array to decrease.

[0005] The present application provides an antenna array, which includes at least one antenna module; the antenna module includes an antenna substrate, a first slot antenna and a second slot antenna; the first slot antenna and the second slot antenna are located on the antenna substrate, the first slot antenna and the second slot antenna share the same slot, and the working mode of the first slot antenna is orthogonal to the working mode of the second slot antenna.

[0006] Optionally, the first slot antenna includes a first port and a first slot; the first port is located at a position on the first slot away from an upper surface of the antenna substrate corresponding to an end of the first microstrip line, and the first port is used to excite the first slot antenna; the first slot is a T-shaped slot, the T-shaped slot is located on the lower surface of the antenna substrate, and the lower surface of the antenna substrate is grounded;

[0007] The second slot antenna includes a second port, a T-shaped top of the first slot and a first microstrip line; the second port is located at an end of the first microstrip line away from the first slot, and the second port is used to excite the second slot antenna; the first microstrip line is an L-shaped microstrip line; the first microstrip line is located on the upper surface of the antenna substrate; the bottom end of the L-shape of the first microstrip line coincides with the top portion of the T-shape of the first slot.

[0008] Optionally, the second slot antenna further includes a second microstrip line, which is an L-shaped microstrip line; the second microstrip line is located on the upper surface of the antenna substrate, and the second microstrip line is connected to the first microstrip line as a whole through the second port.

[0009] Optionally, the first microstrip line and the second microstrip line form an angle of 90° in space.

[0010] Optionally, the first slot antenna further includes a second slot, wherein the second slot is parallel to the top end of the T-shape of the first slot, and the second slot is perpendicular to the bottom end of the T-shape of the first slot.

[0011] Optionally, the second gap is determined according to a position corresponding to a minimum current intensity on the first gap.

[0012] Optionally, the antenna module operates in the N78 frequency band.

[0013] Optionally, the second slot antenna operates in the N78 frequency band and the N79 frequency band, and the first slot antenna operates in the N78 frequency band.

[0014] Optionally, the first slot antenna and the second slot antenna both operate in the N78 frequency band and the N79 frequency band.

[0015] Optionally, an inductor is connected in series at the first port, and the inductor is used for impedance matching.

[0016] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0017] The antenna module provided in the embodiment of the present application realizes mode diversity of the two slot antennas in the antenna module by setting the working modes of the two slot antennas in the antenna array to be orthogonal, thereby improving the isolation between the two slot antennas in the same antenna module and ensuring the radiation performance of the antenna array. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0020] Figure 1 A schematic diagram of an antenna module provided in an embodiment of the present application Figure 1 ;

[0021] Figure 2 A schematic diagram of an antenna array provided in an embodiment of the present application Figure 1 ;

[0022] Figure 3 A schematic diagram of an antenna module provided in an embodiment of the present application Figure 2 ;

[0023] Figure 4 A schematic diagram of an antenna array provided in an embodiment of the present application Figure 2 ;

[0024] Figure 5 A schematic diagram of an antenna module provided in an embodiment of the present application Figure 3 ;

[0025] Figure 6 A schematic diagram of an antenna array provided in an embodiment of the present application Figure 3 ;

[0026] Figure 7 A schematic diagram of an antenna array provided in an embodiment of the present application Figure 4 ;

[0027] Figure 8 A current distribution diagram of a slot antenna provided in an embodiment of the present application in a working frequency band;

[0028] Fig. 9 A schematic diagram of S parameters of an antenna array during a simulation process provided in an embodiment of the present application;

[0029] Fig.10 A schematic diagram of an ECC curve of an antenna array during a simulation process provided in an embodiment of the present application;

[0030] Fig.11 A schematic diagram of the radiation efficiency of an antenna array during a simulation process provided in an embodiment of the present application;

[0031] Fig.12 A schematic diagram of S parameters of an antenna array in practical application provided in an embodiment of the present application;

[0032] Fig.13 A schematic diagram of a comparison of S parameters of an antenna array in a simulation process and in actual application provided in an embodiment of the present application;

[0033] Fig.14 A schematic diagram of a comparison of ECC curves of an antenna array in a simulation process and in actual application provided in an embodiment of the present application;

[0034] Fig.15 A schematic diagram showing a comparison of the radiation efficiency of an antenna array in a simulation process and in actual application provided in an embodiment of the present application;

[0035] Fig.16 A schematic diagram of the radiation direction of an antenna array in the N78 frequency band provided in an embodiment of the present application;

[0036] Fig.17 A schematic diagram of the radiation direction of an antenna array in the N79 frequency band provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0038] In order to solve the problem that the area used for isolation between antennas becomes smaller and smaller due to the expansion of antenna scale, thereby reducing the isolation between antennas and causing the radiation performance of the antenna array to decrease, an embodiment of the present application provides an antenna array, which includes at least one antenna module. The structure of the at least one antenna module is the same. Each antenna module includes an antenna substrate and two slot antennas. Therefore, taking one of the at least one antenna modules as an example, the antenna module in the antenna array in the embodiment of the present application is introduced. The structure of the antenna module can be as follows Figure 1 shown.

[0039] In one possible implementation, the antenna module includes an antenna substrate, a first slot antenna, and a second slot antenna. It should be noted that at least one antenna module in the antenna array may share an antenna substrate, that is, the antenna substrate of the at least one antenna module may be a whole, and the first slot antenna and the second slot antenna are both located on the antenna substrate. Among them, for the same antenna substrate, there is at least one antenna module on the antenna substrate, but each antenna module in this at least one antenna module is independent of each other, that is, each antenna module can work independently on the antenna substrate. Exemplarily, the antenna substrate in the at least one antenna module may be, for example, an Fr-4 dielectric board.

[0040] In addition, the first slot antenna and the second slot antenna share the same slot, and the working mode of the first slot antenna is orthogonal to the working mode of the second slot antenna. Generally, by setting the working mode of the first slot antenna and the working mode of the second slot antenna to be orthogonal, mode diversity between the first slot antenna and the second slot antenna can be achieved, so that when the first slot antenna and the second slot antenna share the same slot, the isolation between the two slot antennas is guaranteed to be greater than 14dB.

[0041] Specifically, the first slot antenna includes a first port and a first slot, and the second slot antenna includes a second port, a T-shaped top of the first slot, and a first microstrip line. That is, the first slot antenna and the second slot antenna share the first slot. The first slot is a T-shaped slot, which is located on the lower surface of the antenna substrate, and the lower surface of the antenna substrate is grounded. The first microstrip line is an L-shaped microstrip line, which is located on the upper surface of the antenna substrate, and the bottom end of the L-shaped first microstrip line overlaps with the top portion of the T-shaped first slot.

[0042] In addition, the first port is located at a position on the upper surface of the antenna substrate corresponding to an end of the first slot away from the first microstrip line, and the first port is used to excite the first slot antenna. The first slot antenna generally radiates through a circular current flowing on the ground plane. The second port is located at an end of the first microstrip line away from the first slot, and the second port is used to excite the second slot antenna. The second slot antenna generally radiates through a resonant cavity formed by the slot on the ground plane and the microstrip line.

[0043] The positional relationship between the first port, the second port, the first slot and the first microstrip line can be as follows: Figure 1 For an introduction to the metal frame, see the following Figure 2 The metal frame in the introduction is not repeated here. Figure 1As shown, in combination with the metal frame, it can also be said that the first port is located at the slot of the metal frame, wherein the slot is an area on the metal frame that contacts the position of the upper surface of the antenna substrate corresponding to the end of the first gap away from the first microstrip line.

[0044] In a possible implementation manner, at least one antenna module in the antenna array is distributed axially symmetrically.

[0045] For example, an antenna array includes four antenna modules, and the four antenna modules are axially symmetrically distributed on an antenna substrate in a metal frame. The structure of the antenna array is as follows: Figure 2 As shown. The four antenna modules are respectively the first antenna module, the second antenna module, the third antenna module and the fourth antenna module. Among them, the first antenna module includes an antenna substrate, a first slot antenna and a second slot antenna, the second antenna module includes an antenna substrate, a third slot antenna and a fourth slot antenna, the third antenna module includes an antenna substrate, a fifth slot antenna and a sixth slot antenna, and the fourth antenna module includes an antenna substrate, a seventh slot antenna and an eighth slot antenna. It should be noted that the above-mentioned metal frame can be used to simulate a mobile phone case, and the influence of the metal frame on the antenna array can be regarded as the influence of the mobile phone case on the antenna array placed in the mobile phone. In addition, there is a gap between the antenna substrate and the metal frame, which can be used to place a 4G antenna. The number of the gaps can be Figure 2 Two shown.

[0046] In the above Figure 2 In the example of the antenna array given, the first slot antenna includes a first port and a first slot, and the second slot antenna includes a second port, a T-shaped top of the first slot, and a first microstrip line. Similarly, the third slot antenna includes a third port and a third slot, and the fourth slot antenna includes a fourth port, a T-shaped top of the third slot, and a third microstrip line. The fifth slot antenna includes a fifth port and a fifth slot, and the sixth slot antenna includes a sixth port, a T-shaped top of the fifth slot, and a fifth microstrip line. The seventh slot antenna includes a seventh port and a seventh slot, and the eighth slot antenna includes an eighth port, a T-shaped top of the seventh slot, and a seventh microstrip line. In addition, for the introduction of the antenna substrate and the slot antenna in the second antenna module, the third antenna module, and the fourth antenna module, please refer to the above introduction of the antenna substrate and the slot antenna in the first antenna module, which will not be repeated here.

[0047] In addition, Figure 2Taking the antenna array shown as an example, the size of the antenna array and the size of the antenna module in the antenna array are introduced. The size of the metal frame is l1*l2, where l1 is 145mm and l2 is 75mm. The width of the metal frame is uniform, and the width of the metal frame can be ignored, that is, l2-l4=0. The size of the antenna substrate is l3*l4, where l3 is 135mm, l4 is 75mm, and the height of the antenna substrate can be 0.8mm. The size of the gap between the metal frame and the antenna substrate that can be used to place the 4G antenna is l5*l4, where l5 is 5mm and l4 is 75mm. The sizes of the first microstrip line are b2*b1, b3*b1 and b1*b1, where b2 is 2.5mm, b3 is 5.25mm, b1 is the width of the microstrip line, and b1 is 1.5mm. The dimensions of the first gap are a1*a2 and a1*a3, where a2 is 28.4 mm, a3 is 5 mm, a1 is the width of the first gap, and a1 is 1 mm. It should be noted that Figure 2 Mainly used to show the structure of antenna array, Figure 2 The dimensions of the antenna array shown are not scaled according to the dimensions of the antenna array; therefore, Figure 2 The width of the gap may not be completely consistent, and there may be a situation where the width of the gap is greater than the width of the microstrip line. In other words, Figure 2 The dimensions of the antenna array shown are based on the above description. Similarly, the following description of the dimensions of the antenna array is based on the textual description of the corresponding example part.

[0048] In another possible implementation manner, at least one antenna module in the antenna array is randomly distributed.

[0049] It should be noted that in the above Figure 1-Figure 2 In the corresponding implementation, at least one antenna module in the antenna array operates in the N78 frequency band. Among them, the N78 frequency band described in the embodiment of the present application is 3400MHz-36MHz, which will not be described in detail below. In addition, in the above-mentioned antenna module, by setting the working mode of the first slot antenna to be orthogonal to the working mode of the second slot antenna, the mode diversity between the first slot antenna and the second slot antenna in the antenna module can be achieved, thereby improving the isolation between the first slot antenna and the second slot antenna when the area available for isolation between the antennas is small, improving the space utilization, and ensuring the radiation performance of the antenna array.

[0050] In order to achieve the above Figure 1 The high frequency response of the second slot antenna in the given antenna module, or in other words, in order to enable the second slot antenna to operate at high frequencies, the embodiment of the present application Figure 1 Another antenna module is provided based on the antenna module shown.

[0051] Relative to Figure 1 The antenna module shown in the embodiment of the present application adds a second microstrip line to another antenna module provided in the embodiment of the present application. In this case, the first slot antenna includes a first port and a first slot, and the second slot antenna includes a second port, a T-shaped top of the first slot, a first microstrip line, and a second microstrip line. For the introduction of the first slot antenna and the introduction of the antenna substrate in the slot antenna, please refer to the above content and will not be repeated here.

[0052] The second microstrip line is an L-shaped microstrip line, and the second microstrip line is located on the upper surface of the antenna substrate. In addition, the second microstrip line and the first microstrip line are connected as a whole through the second port. That is to say, since the second port is located at the end of the first microstrip line away from the first gap, the first microstrip line and the second microstrip line can be regarded as being connected in parallel through the second port.

[0053] In a possible implementation, the first microstrip line and the second microstrip line form a 90° angle in space. In this case, the first microstrip line and the second microstrip line are orthogonal. The orthogonality between the antenna structures can reduce the mutual coupling between the antenna structures, thereby ensuring the radiation performance of the first slot antenna and the second slot antenna.

[0054] Exemplarily, the structure of the antenna module including the second microstrip line may be as follows: Figure 3 That is to say, the positional relationship between the first microstrip line, the second microstrip line, the first port, the second port and the first gap can be seen in Figure 3 .

[0055] In a possible implementation manner, the at least one antenna module including the second microstrip line may be distributed axially symmetrically.

[0056] For example, an antenna array includes four antenna modules, and the four antenna modules are axially symmetrically distributed on an antenna substrate in a metal frame. The structure of the antenna array is as follows: Figure 4 As shown. The four antenna modules are the first antenna module, the second antenna module, the third antenna module and the fourth antenna module. The first antenna module includes an antenna substrate, a first slot antenna and a second slot antenna, the second antenna module includes an antenna substrate, a third slot antenna and a fourth slot antenna, the third antenna module includes an antenna substrate, a fifth slot antenna and a sixth slot antenna, and the fourth antenna module includes an antenna substrate, a seventh slot antenna and an eighth slot antenna. For an introduction to the metal frame and the gap between the metal frame and the antenna substrate, please refer to the above Figure 2 The content is introduced with examples and will not be repeated here.

[0057] exist Figure 4In the example of the antenna array given, the introduction of the first slot antenna, the third slot antenna, the fifth slot antenna and the seventh slot antenna can also be referred to the above Figure 2 The contents introduced by the given examples are not repeated here. The second slot antenna includes a second port, a T-shaped top of the first slot, a first microstrip line, and a second microstrip line. Similarly, the fourth slot antenna includes a fourth port, a T-shaped top of the third slot, a third microstrip line, and a fourth microstrip line, the sixth slot antenna includes a sixth port, a T-shaped top of the fifth slot, a fifth microstrip line, and a sixth microstrip line, and the eighth slot antenna includes an eighth port, a T-shaped top of the seventh slot, a seventh microstrip line, and an eighth microstrip line.

[0058] In addition, Figure 4 For example, the size of the metal frame, the size of the antenna substrate, the size of the gap between the metal frame and the antenna substrate, the size of the first microstrip line, and the size of the first gap can be referred to above. Figure 2 The description of the given example is omitted here. The dimensions of the second microstrip line are b4*b1 and b2*b1, wherein b4 is 23 mm.

[0059] In the above Figure 3-Figure 4 In the corresponding implementation, the second slot antenna in the antenna module operates in the N78 and N79 frequency bands, and the first slot antenna operates in the N78 frequency band. That is, by adding a second microstrip line, the high-frequency response of the second slot antenna can be achieved. Among them, the N79 frequency band described in the embodiment of the present application is 4800MHz-5000MHz, which will not be repeated below.

[0060] In order to achieve the above Figure 3 The first slot antenna of the antenna module given resonates at high frequency, or in other words, in order to make the first slot antenna work at high frequency, the embodiment of the present application Figure 3 Another antenna module is also provided based on the antenna module shown.

[0061] Relative to Figure 3 In the antenna module shown in the figure, another antenna module provided in the embodiment of the present application adds a second slot. In this case, the first slot antenna includes a first port, a first slot and a second slot, and the second slot antenna includes a second port, a T-shaped top of the first slot, a first microstrip line and a second microstrip line. For an introduction to the second slot antenna, please refer to the above description of Figure 3 The introduction of the second slot antenna in the embodiment will not be repeated here. In addition, the introduction of the antenna substrate in the slot antenna can also be referred to the above content, which will not be repeated here.

[0062] The second slot is parallel to the top of the T-shaped structure of the first slot, and is perpendicular to the bottom of the T-shaped structure of the first slot. The second slot is located on the lower surface of the antenna substrate.

[0063] Exemplarily, the structure of the antenna module including the second slot may be as follows: Figure 5 That is to say, the positional relationship between the first microstrip line, the second microstrip line, the first port, the second port, the first slot and the second slot can be seen in Figure 5 .

[0064] It should be noted that adding the second slot can make the first slot antenna resonate at a high frequency, so that the first slot antenna can operate at a high frequency.

[0065] Specifically, the second slot is determined according to the position corresponding to the minimum current intensity on the first slot. It should be noted that, in this way, the influence of the newly added second slot on the existing resonance mode can be reduced, so that the first slot and the second slot work independently at different frequencies.

[0066] For example, an antenna array includes four antenna modules, and the four antenna modules are axially symmetrically distributed on an antenna substrate in a metal frame. The structure of the antenna array is as follows: Figure 6 As shown. The four antenna modules are the first antenna module, the second antenna module, the third antenna module and the fourth antenna module. The first antenna module includes an antenna substrate, a first slot antenna and a second slot antenna, the second antenna module includes an antenna substrate, a third slot antenna and a fourth slot antenna, the third antenna module includes an antenna substrate, a fifth slot antenna and a sixth slot antenna, and the fourth antenna module includes an antenna substrate, a seventh slot antenna and an eighth slot antenna. For an introduction to the metal frame and the gap between the metal frame and the antenna substrate, please refer to the above Figure 2 The content is introduced with examples and will not be repeated here.

[0067] exist Figure 6 In the example of the antenna array given, the introduction of the second slot antenna, the fourth slot antenna, the sixth slot antenna and the eighth slot antenna can be referred to the above Figure 4 The contents introduced by the given examples are not repeated here. The first slot antenna includes a first port, a first slot and a second slot. Similarly, the third slot antenna includes a third port, a third slot and a fourth slot, the fifth slot antenna includes a fifth port, a fifth slot and a sixth slot, and the seventh slot antenna includes a seventh port, a seventh slot and an eighth slot.

[0068] In addition, Figure 6For example, the size of the metal frame, the size of the antenna substrate, the size of the gap between the metal frame and the antenna substrate, the size of the first microstrip line, and the size of the first gap can be referred to above. Figure 2 For an introduction to the example given, the size of the second microstrip line can be found in the above description of Figure 4 The description of the given example is omitted here. The size of the second gap is a4*a1, where a4 is 9.7 mm, a1 is the width of the second gap, and a1 is 1 mm.

[0069] It should be noted that in Figure 5-Figure 6 In the corresponding implementation, Figure 5 The first slot antenna and the second slot antenna in the given antenna module can both operate in the N78 frequency band and the N79 frequency band. In other words, the two slot antennas in each antenna module in the antenna array can both operate in the N78 frequency band and the N79 frequency band.

[0070] In a possible implementation manner, an inductor is connected in series at the first port, and the inductor is used for impedance matching.

[0071] For example, Figure 7 As shown, Figure 6 Taking the antenna array shown as an example, the first port is connected in series with a first inductor, similarly, the third port is connected in series with a second inductor, the fifth port is connected in series with a third inductor, and the seventh port is connected in series with a fourth inductor.

[0072] In order to more clearly reflect Figure 5 The antenna module shown is relative to Figure 1 The invention also discloses the role of the gap and microstrip line added in the antenna module shown in FIG. Figure 5 Taking the antenna module shown in FIG. 1 as an example, a current distribution diagram of the first slot antenna and the second slot antenna in the antenna module working in the N78 frequency band, and a current distribution diagram of the first slot antenna and the second slot antenna in the antenna module working in the N79 frequency band are given, as shown in FIG. Figure 8 As shown in (a)-(d).

[0073] in, Figure 8 (a) is a current distribution diagram of the first slot antenna operating in the N78 frequency band. At this time, the current is mainly distributed near the first slot. Figure 8 (c) is the current distribution diagram of the first slot antenna working in the N79 frequency band. At this time, the current is mainly distributed near the second slot. That is to say, when the first slot antenna works at a low frequency, it mainly relies on the first slot to achieve radiation. When the first slot antenna works at a high frequency, it mainly relies on the second slot to achieve radiation.

[0074] It should be noted that the slot antenna operates in full-wave mode at low frequencies and in half-wave mode at high frequencies. Taking the first slot antenna as an example, the resonant frequency of the first slot antenna is inversely proportional to the size of the first slot antenna, and the resonant frequency is inversely proportional to the wavelength, that is, for the first slot antenna, the wavelength is associated with the size. Combined with a2 in the first slot (for example, 28.4 mm above), the length a4 of the second slot (for example, 9.7 mm above) and Wherein, f1 is 3.4 (GHz), f2 is 4.9 (GHz), λ1 is the wavelength when the resonant frequency is f1, and λ2 is the wavelength when the resonant frequency is f2. Therefore, it can be determined that the first slot antenna works in a half-wave mode at high frequencies.

[0075] Figure 8 (b) is the current distribution diagram of the second slot antenna working in the N78 frequency band. Figure 8 In (b), the length of the resonant cavity formed by the second slot antenna is equal to the length of the top of the T-shape of the first slot. Figure 8 (d) is the current distribution diagram of the second slot antenna working in the N79 frequency band. Figure 8 In (d), after the second microstrip line is added to the second slot antenna, the second slot antenna forms a new resonant cavity at high frequencies. Combined with the length a2 of the top of the T-shaped first slot (e.g., 28.4 mm above), the length of the new resonant cavity can be Among them, f1 is 3.4 (GHz), f2 is 4.9 (GHz), λ1 is the wavelength when the resonant frequency is f1, λ2 is the wavelength when the resonant frequency is f2, and x is the length of the new resonant cavity.

[0076] Below Figure 7 Taking the antenna array as an example, the simulation results of the antenna array and the effect in practical application are explained:

[0077] With the above Figure 7 Taking the antenna array as an example, the antenna performance simulation is performed to obtain the S parameters of the antenna array, such as Fig. 9 As shown. It should be noted that, generally, when the isolation between antennas is high, the signal transmission loss between antennas is relatively small, that is, the crosstalk between antennas is relatively small. That is to say, in the antenna array given in the embodiment of the present application, the size of the S parameter between the two antennas in the antenna module is mainly observed to determine the signal loss between the two antennas, that is, the size of the signal crosstalk, thereby determining the performance of the antenna array. Therefore, although Fig. 9 Only some simulation data about the S parameters between antennas are given, but it can also be seen Fig. 9 Determine the performance of the antenna array.

[0078] exist Fig. 9 In the figure, the horizontal axis is the working frequency of the antenna, and the vertical axis is the value of the S parameter. Among them, S11 represents the return loss (also known as the reflection coefficient) of the signal output from the first port at the first port, S15 represents the loss (or coupling coefficient) of the signal output from the first port at the fifth port, S21 represents the coupling coefficient of the signal output from the second port at the first port, S22 represents the return loss of the signal output from the second port at the second port, and S32 represents the coupling coefficient of the signal output from the third port at the second port. Fig. 9 The S parameters between the antennas in the N78 and N79 bands shown in the figure indicate that the crosstalk between the antenna arrays mainly exists in the antenna module, and after performing mode diversity on the two slot antennas in the antenna module, the isolation between the first port and the second port can be guaranteed to be greater than 14dB.

[0079] With the above Fig. 9 The simulation data in is used as an example to calculate and obtain the envelope correlation coefficient (ECC) curve between antennas, as shown in Fig.10 It should be noted that Fig.10 Only three ECC curves with reference value are provided. Fig.10 In , Ant1-Ant2 is the ECC value between the first slot antenna and the second slot antenna, Ant1-Ant5 is the ECC value between the first slot antenna and the fifth slot antenna, and Ant2-Ant3 is the ECC value between the second slot antenna and the third slot antenna. Fig.10 When the antenna works in the N78 and N79 frequency bands, the maximum ECC value of the above three curves does not exceed 0.03, and when the antenna works in the N78 and N79 frequency bands, the ECC value between the two slot antennas in the same antenna module is also less than 0.05.

[0080] At this time, the radiation efficiency of the antennas in the antenna array in the N78 and N79 frequency bands is as follows: Fig.11 As shown. Wherein, Ant1 represents the radiation efficiency of the first slot antenna, and Ant2 represents the radiation efficiency of the second slot antenna. Fig.11 As shown, in the N78 frequency band, the radiation efficiency of the first antenna module including the first slot antenna and the second slot antenna is 45%-69%, and in the N79 frequency band, the radiation efficiency of the first antenna module including the first slot antenna and the second slot antenna is 40%-60%.

[0081] Figure 7 In the actual application of the given antenna array, the curve of the S parameter between the antennas can be obtained as follows: Fig.12 As shown. Fig.12In, S11 represents the return loss of the signal output from the first port at the first port measured in the actual application process, S22 represents the return loss of the signal output from the first port at the first port measured in the actual application process, S12 represents the coupling coefficient of the signal output from the first port at the second port measured in the actual application process, S13 represents the coupling coefficient of the signal output from the first port at the third port measured in the actual application process, S15 represents the coupling coefficient of the signal output from the first port at the fifth port measured in the actual application process, S23 represents the coupling coefficient of the signal output from the second port at the third port measured in the actual application process, S24 represents the coupling coefficient of the signal output from the second port at the fourth port measured in the actual application process, and S25 represents the coupling coefficient of the signal output from the second port at the fifth port measured in the actual application process. Fig.12 It can be determined that within the working frequency band, the isolation of the slot antenna in the same antenna module is greater than 14 dB, and the isolation between the two antenna modules is greater than 20 dB.

[0082] It should be noted that Figure 7 In the actual application of the given antenna array, the microstrip line in the second slot antenna is usually fed through an SMA connector. Generally, the SMA connector is welded to the ground plane, i.e., the lower surface of the antenna substrate. Similarly, the fourth slot antenna, the sixth slot antenna, and the eighth slot antenna in other antenna modules all feed the microstrip line in the antenna through an SMA connector. In addition, the first slot antenna is fed through a coaxial connector (e.g., a 50Ω coaxial connector) welded on a metal frame. Similarly, the third slot antenna, the fifth slot antenna, and the seventh slot antenna are all fed through a 50Ω coaxial connector welded on a metal frame. In one possible implementation, the outer conductor of a 50Ω coaxial cable is welded to one side of a metal frame, and the inner conductor is welded to the other side of the metal frame after an inductor (e.g., a 2nH inductor) is welded in series.

[0083] like Fig.13 As shown, S11-Simulated represents the return loss of the signal output from the first port at the first port during the simulation process, S11-Measured represents the return loss of the signal output from the first port at the first port measured during the actual application process, S22-Simulated represents the return loss of the signal output from the second port at the second port during the simulation process, and S22-Measured represents the return loss of the signal output from the second port at the second port measured during the actual application process. Fig.13It can be determined that the measurement result S11-Measured and the simulation result S11-Simulated have high similarity, the measurement result S22-Measured and the simulation result S22-Simulated have high similarity, and the first slot antenna and the second slot antenna both have a return loss of more than 10 dB in the working frequency band (N78 band and N79 band).

[0084] For example, Figure 7 Taking the antenna array in FIG. 1 as an example, the ECC curve of the antenna array obtained by calculating the S parameters actually measured for the 8MIMO antenna array can be as follows: Fig.14 (a) and Fig.14 As shown in (b) in . Fig.14 (a) is the ECC curve of the antenna array obtained by calculating the S parameters actually measured for the 8MIMO antenna array in the N78 frequency band. Fig.14 (b) is the ECC curve of the antenna array obtained by calculating the S parameters actually measured for the 8MIMO antenna array in the N79 frequency band. Wherein, Ant1-Ant2-Simulated represents the ECC value of the signal output from the first port at the second port during the simulation process, Ant2-Ant3-Simulated represents the ECC value of the signal output from the second port at the third port during the simulation process, Ant1-Ant5-Simulated represents the ECC value of the signal output from the first port at the fifth port during the simulation process, Ant1-Ant2-Measured represents the ECC value of the signal output from the first port at the second port during the actual measurement process, Ant2-Ant3-Measured represents the ECC value of the signal output from the second port at the third port during the actual measurement process, and Ant1-Ant5-Measured represents the ECC value of the signal output from the first port at the fifth port during the actual measurement process.

[0085] It should be noted that through Fig.14 It can be seen that Figure 7 In actual measurements, the ECC values ​​of the antenna array shown are all less than 0.05 in the working frequency band, that is, the antenna array has good diversity performance, that is, the mode diversity effect in the antenna array is good.

[0086] For example, in a microwave darkroom Figure 7 The measured radiation efficiency of the antenna array shown is Fig.15 (a) and Fig.15 as shown in (b). Fig.15 (a) is the radiation efficiency of the antenna array actually measured on the N78 frequency band. Fig.15 (b) is the radiation efficiency of the antenna array obtained by actually measuring the antenna array on the N79 frequency band. Wherein, Ant1-Simulated represents the radiation efficiency of the first slot antenna during the simulation process, Ant2-Simulated represents the radiation efficiency of the second slot antenna during the simulation process, Ant1-Measured represents the radiation efficiency of the first slot antenna during the actual measurement process, and Ant2-Measured represents the radiation efficiency of the second slot antenna during the actual measurement process. Fig.15 It can be seen from (a) that the (actual) radiation efficiency of the slot antenna in the antenna module is higher than the expected (simulated) radiation efficiency in the N78 frequency band, and the (actual) radiation efficiency of the slot antenna in the antenna module is consistent with the expected (simulated) radiation efficiency in the N79 frequency band. In addition, Theta = 0 means that the angle on the elevation plane (vertical plane) is 0, Phi = 0 means that the angle on the azimuth plane (horizontal plane) is 0, Theta = 0 means that the angle on the elevation plane (vertical plane) is 0, Phi = 0 means that the angle on the azimuth plane (horizontal plane) is 0, Theta = 90 means that the angle on the elevation plane (vertical plane) is 90, and Phi = 90 means that the angle on the azimuth plane (horizontal plane) is 90.

[0087] For example, in a microwave darkroom Figure 7 The radiation direction measured by the antenna array shown is as follows Fig.16 and Fig.17 As shown. Among them, Fig.16 is the radiation direction actually measured for the antenna array in the N78 frequency band (e.g., 3.5 GHz), Fig.17 is the radiation direction of the antenna array actually measured in the N79 frequency band (for example, 4.9 GHz). Wherein, Sim-Eyheta represents the radiation direction of the antenna array on the E plane during the simulation process, Sim-Ephi represents the radiation direction of the antenna array on the P plane during the simulation process, Mea-Eyheta represents the radiation direction of the antenna array on the E plane during the actual measurement process, and Mea-Ephi represents the radiation direction of the antenna array on the P plane during the actual measurement process. Fig.16 and Fig.17 It can be seen that in the working frequency bands (N78 band and N79 band), the radiation direction of the antenna actually measured and the radiation pattern of the antenna obtained by simulation are highly similar, that is, the feeding structure used in the actual measurement of the antenna array is reasonable.

[0088] It should be noted that the above-mentioned Figure 7 When measuring the antenna array shown, except for the slot antenna under test, the ports of the other seven slot antennas are connected to a 50Ω matching load.

[0089] The following table 1 compares the structure and performance of the antenna array in the prior art and the antenna array provided in the embodiment of the present application:

[0090] Table 1

[0091]

[0092]

[0093]

[0094] It can be seen from the above Table 1 that the MIMO antenna array provided in the embodiment of the present application has a higher isolation and a lower ECC value among all the dual-band antenna arrays shown in Table 1. Even compared with the single-band antenna array, the isolation and ECC value of the antenna array provided in the embodiment of the present application are more ideal (i.e., the isolation is higher and the ECC value is lower). In addition, the return loss of the antenna array in the working frequency band is maintained above 10dB, and it has relatively good radiation performance. Therefore, the MIMO antenna array proposed in the embodiment of the present application has better performance.

[0095] It should be noted that the antenna array provided in the embodiment of the present application is a high-isolation dual-frequency 8-unit antenna array based on mode diversity, which can better adapt to 5G MIMO applications. In the two frequency bands of N78 and N79, the antenna array has a return loss of more than 10dB, and the isolation between antennas is greater than 14dB. In addition, the ECC value between antennas is less than 0.05, the antenna has a total efficiency of more than 40%, and the measurement results are highly consistent with the simulation results. More importantly, the antenna array obtained based on mode diversity has a higher space utilization rate than the previous antenna array structure. Therefore, the 8×8 MIMO antenna array proposed in the embodiment of the present application can better guarantee antenna performance while ensuring space utilization.

[0096] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0097] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An antenna array, It is characterized in that The antenna array includes at least one antenna module; the antenna module includes an antenna substrate, a first slot antenna and a second slot antenna; the first slot antenna and the second slot antenna are located on the antenna substrate, the first slot antenna and the second slot antenna share the same slot, and an operating mode of the first slot antenna is orthogonal to an operating mode of the second slot antenna; The first slot antenna comprises a first port and a first slot; the first port is located at a position on the upper surface of the antenna substrate corresponding to an end of the first slot away from the first microstrip line, and the first port is used to excite the first slot antenna; the first slot is a T-shaped slot, the T-shaped slot is located on the lower surface of the antenna substrate, and the lower surface of the antenna substrate is grounded; The second slot antenna includes a second port, a T-shaped top of the first slot and the first microstrip line; the second port is located at an end of the first microstrip line away from the first slot, and the second port is used to excite the second slot antenna; the first microstrip line is an L-shaped microstrip line; the first microstrip line is located on the upper surface of the antenna substrate; the bottom end of the L-shape of the first microstrip line coincides with the top portion of the T-shape of the first slot.

2. The antenna array according to claim 1, It is characterized in that The second slot antenna also includes a second microstrip line, which is an L-shaped microstrip line; the second microstrip line is located on the upper surface of the antenna substrate, and the second microstrip line and the first microstrip line are connected as a whole through the second port.

3. The antenna array according to claim 2, It is characterized in that The first microstrip line and the second microstrip line form an angle of 90° in space.

4. The antenna array according to claim 3, It is characterized in that The first slot antenna further includes a second slot, wherein the second slot is parallel to the top end of the T-shape of the first slot, and the second slot is perpendicular to the bottom end of the T-shape of the first slot.

5. The antenna array according to claim 4, It is characterized in that The second gap is determined according to a position corresponding to a minimum current intensity on the first gap.

6. The antenna array according to claim 1, It is characterized in that The antenna module operates in the N78 frequency band.

7. The antenna array according to claim 2 or 3, It is characterized in that The second slot antenna operates in the N78 frequency band and the N79 frequency band, and the first slot antenna operates in the N78 frequency band.

8. The antenna array according to claim 4 or 5, It is characterized in that The first slot antenna and the second slot antenna both operate in the N78 frequency band and the N79 frequency band.

9. The antenna array according to claim 1, It is characterized in that An inductor is connected in series at the first port, and the inductor is used for impedance matching.

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