EP4589775A1

EP4589775A1 - Antenna module and communication device

Info

Publication number: EP4589775A1
Application number: EP23878995.2A
Authority: EP
Inventors: Yonghui YANG; Lin Wang; Dacheng Wang; Shan Wang; Yajuan DUAN
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2022-10-18
Filing date: 2023-10-10
Publication date: 2025-07-23
Also published as: CN117954868A; EP4589775A4; WO2024083003A1

Abstract

The present disclosure provides an antenna module and a communication device. The antenna module comprises a substrate, an antenna array, and N beamforming chips; the antenna array is arranged on the substrate and comprises a plurality of antenna elements, and the plurality of antenna elements are divided into M antenna element groups; each beamforming chip is connected to a plurality of antenna elements in one antenna array group; M is greater than N, and M and N are both positive integers.

Description

The present disclosure claims priority to Chinese Patent Application No. 202211275795.8, filed on October 18, 2022 , the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the field of communication technologies, and in particular, to an antenna module and a communication device.

BACKGROUND

Fifth-generation mobile communication technology (5th Generation Mobile Communication Technology, 5G) is a new-generation broadband mobile communication technology characterized by high speed, low latency, and large connection, and the 5G communication infrastructure is a network basic infrastructure for implementing interconnection of humans, machines, and objects.
The 5G mobile communication technology may provide users with high-quality experiences such as higher-speed network access, lower-delay response speed, and an ultra-large-capacity number of wireless device connections. Compared to the Sub-6 GHz frequency band which has been commercially used, the millimeter wave frequency band has rich spectrum resources, which may satisfy application scenarios such as a high-bandwidth hotspot area. Additionally, a low-latency characteristic of the millimeter wave communication is conducive to constructing complete industrial interconnections in the industrial field, and significantly improving production efficiency, management efficiency, and product manufacturing reliability of the manufacturing industry.

SUMMARY

In a first aspect, embodiments of the present disclosure provide an antenna module. The antenna module includes: an antenna array, where the antenna array includes multiple antenna array elements, and the multiple antenna array elements are grouped into M antenna array element groups; and N beamforming chips, where each beamforming chip is connected to a plurality of antenna array elements in an antenna array element group; where M > N, and both M and N are positive integers.
In some embodiments, the M antenna array element groups are arranged in an array; among the M antenna array element groups, antenna array element groups connected to the beamforming chips are first antenna array element groups, and antenna array element groups other than the first antenna array element groups are second antenna array element groups; and any two of the second antenna array element groups are not adjacent in row direction or column direction.
In some embodiments, the M antenna array element groups are arranged in an array; among the M antenna array element groups, antenna array element groups connected to the beamforming chips are first antenna array element groups, and antenna array element groups other than the first antenna array element groups are second antenna array element groups; a number of antenna array element groups adjacent to at least one of the second antenna array element groups in row direction and column direction is greater than or equal to a number of antenna array element groups adjacent to any one of the first antenna array element groups in the row direction and the column direction, and the row direction and the column direction are row direction and column direction in which the M antenna array element groups are arranged.
In some embodiments, along the row direction or the column direction, at least one of the first antenna array element groups exists between any two of the second antenna array element groups.
In some embodiments, a quantitative relationship between N and M satisfies that: a difference value between an ideal equivalent isotropically radiated power of the antenna array and an actual equivalent isotropically radiated power of the antenna array is less than or equal to a set value. The ideal equivalent isotropically radiated power of the antenna array is an equivalent isotropically radiated power obtained when the antenna array is controlled by M beamforming chips, and the actual equivalent isotropically radiated power of the antenna array is an equivalent isotropically radiated power obtained when the antenna array is controlled by the N beamforming chips.
In some embodiments, the above-mentioned set value is 2 dB to 3 dB.
In some embodiments, the quantitative relationship between N and M is $\frac{3}{5} M \leq$ $N \leq \frac{7}{8} M$ .
In some embodiments, when $N = \frac{3}{4} M$ , the antenna array includes multiple antenna array element group units, each of the antenna array element group units includes adjacent four antenna array element groups; and among the four antenna array element groups in the each antenna array element group unit, three antenna array element groups of the four antenna array element groups belong to the first antenna array element groups, and remaining one antenna array element group of the four antenna array element groups belongs to the second antenna array element groups.
In some embodiments, when $N = \frac{7}{8} M$ , the antenna array includes multiple antenna array element group units, each of the antenna array element group units includes adjacent eight antenna array element groups; and among eight antenna array element groups in the each antenna array element group unit, seven antenna array element groups of the eight antenna array element groups belong to the first antenna array element groups, and remaining one antenna array element group of the eight antenna array element groups belongs to the second antenna array element groups.
In some embodiments, each second antenna array element group has at least three adjacent antenna array element groups in both the row direction and the column direction.
In some embodiments, the antenna array element is configured as a dual-polarized antenna array element; the beamforming chip is configured as a dual-polarized beamforming chip; and the antenna module further includes a power division network, the power division network is electrically connected to the N beamforming chips respectively, and the power division network is configured as a dual-polarized power division network.
In a second aspect, the embodiments of the present disclosure provide a communication device. The communication device includes the antenna module provided in the above first aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are used to provide a further understanding of technical solutions of the present disclosure, and form a part of the specification, and are used in conjunction with the embodiments of the present disclosure to explain the technical solutions of the present disclosure, and do not constitute a limitation on the technical solutions of the present disclosure.

FIG. 1 is a schematic diagram of an antenna module that is commonly used currently according to some embodiments.
FIG. 2 is a schematic diagram of a sparse array of an antenna module that is commonly used currently according to some embodiments.
FIG. 3A is an architectural diagram of an antenna module according to some embodiments.
FIG. 3B is an architectural diagram of another antenna module according to some embodiments.
FIG. 4 is a structural diagram of an antenna module according to some embodiments.
FIG. 5A is a schematic diagram of an architecture of an antenna module according to some embodiments.
FIG. 5B is a schematic diagram of a multi-layer high-density interconnection according to some embodiments.
FIG. 6 is a schematic diagram of a spherical coordinate system according to some embodiments.
FIG. 7 is a schematic diagram of feed source phases of adjacent antennas of beamforming according to some embodiments.
FIG. 8 is a schematic diagram of in-phase beamforming according to some embodiments.
FIG. 9 is a schematic diagram of wavelengths of beamforming according to some embodiments.
FIG. 10 is a schematic diagram of gain curves before and after phase conversion of beamforming according to some embodiments.
FIG. 11A and FIG. 11B are schematic diagrams of an architecture of a patch slot antenna according to some embodiments.
FIG. 12 is a circuit structure diagram of a Wilkinson equal-division one-to-two power divider according to some embodiments.
FIG. 13 is a schematic diagram of a Wilkinson power divider network according to some embodiments.
FIG. 14 is a schematic diagram of an 8×8 full array according to some embodiments.
FIG. 15 is a schematic diagram of an 8×8 with an antenna array element on a corner having an excitation amplitude less than an ideal excitation amplitude by 10 dB according to some embodiments.
FIG. 16 is a schematic diagram of an 8×8 array with a certain array element at the center having an excitation amplitude less than an ideal excitation amplitude by 10 dB according to some embodiments.
FIG. 17 is a schematic diagram of an 8×8 antenna array with array elements on four corners having excitation amplitudes less than an ideal excitation amplitude by 10 dB according to some embodiments.
FIG. 18 is a schematic diagram of an 8×8 antenna array with four antennas at the center having excitation amplitudes less than an ideal excitation amplitude by 10 dB according to some embodiments.
FIG. 19 is a schematic diagram of an 8×8 antenna array with 16 antennas at the center having excitation amplitudes less than an ideal excitation amplitude by 10 dB according to some embodiments.
FIG. 20 is an architectural diagram of yet another antenna module according to some embodiments.
FIG. 21 is an architectural diagram of yet another antenna module according to some embodiments.
FIG. 22 is an architectural diagram of yet another antenna module according to some embodiments.
FIG. 23 is an architectural diagram of yet another antenna module according to some embodiments.
FIG. 24 is a schematic diagram of a communication device according to some embodiments.

DETAILED DESCRIPTION

To enable those skilled in the art to better understand the technical solutions of the embodiments of the present disclosure, the technical solutions in the embodiments of the present disclosure will be described clearly and completely below in conjunction with the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are only a part of the embodiments of the present disclosure, but not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those ordinary skilled without creative efforts shall fall within the protection scope of the present disclosure.
It should be noted that all directional indications (such as top, bottom, left, right, front, back, etc.) in the embodiments of the present disclosure are only used to explain relative positional relationships, movements, etc., of various components under a specific posture (as shown in the drawings), and if the specific posture changes, the directional indications also change accordingly.
In the description of the present disclosure, unless otherwise specified, "/" means "or", and for example, A/B may represent A or B. The term "and/or" herein merely describes an associated relationship between associated objects, and represents that three relationships may exist, and for example, "A and/or B" may represent: only A, only B, or both A and B. The terms "first" and "second", etc., are used for descriptive purposes only, but cannot be understood as indicating or implying relative importance or implicitly specifying the number of the indicated technical features. Thus, features defined with "first" or "second", etc., may explicitly or implicitly include one or more such features. In the description of the present disclosure, unless otherwise specified, "multiple / a plurality of" means two or more.
In the description of the present disclosure, it should be noted that, unless explicitly specified or limited, the terms "interconnected" or "connected / coupled" should be understood broadly, and for example, they may refer to a fixed connection, a detachable connection, or an integral connection. Those ordinary skilled in the art may understand the specific meanings of the above terms in the present disclosure in specific cases. Additionally, when describing a pipeline, the terms "interconnected" or "connected / coupled" in the present disclosure means conduction. The specific meaning should be understood in context. In the embodiments of the present disclosure, terms such as "exemplarily" or "for example", etc., are used to provide examples, illustrations, or explanations / descriptions. Any embodiment or designed solution described as "exemplarily" or "for example" in the embodiments of the present disclosure should not be interpreted as being more preferred or advantageous than other embodiments or designed solutions. Rather, the use of the terms such as "exemplarily" or "for example" is intended to present related concepts in detail.
In some technologies, a design of a large-scale array antenna and an integrated design of encapsulated antenna and chip in the 5G millimeter wave system are two key technologies. A highly-integrated antenna module includes beamforming chips, an antenna array, and a power division network. Due to a limitation on power consumption density and the increase in the number of beamforming chip channels, the difficulty of thermal dissipation also increases accordingly. Moreover, the cost of the antenna module is also a consideration in the module design.
Based on this, some embodiments of the present disclosure provide an antenna module and a communication device. By improving the antenna module, it is easy for thermal dissipation, and the cost may be reduced. The antenna module and the communication device are described below.
FIG. 1 is a schematic diagram of an antenna module that is commonly used currently according to some embodiments. As shown in FIG. 1, the current antenna module 100 includes: a substrate 11, an antenna array 12, and multiple beamforming chips 13. The antenna array 12 and the beamforming chips 13 are disposed on two opposite sides of the substrate 11; the antenna array 12 includes multiple antenna array elements 121, and an antenna array element 121 is an individual component in the antenna array 12, the multiple antenna array elements 121 are grouped into multiple antenna array element groups 14, and for example, each antenna array element group 14 includes four antenna array elements 121; and each beamforming chip 13 of the multiple beamforming chips 13 is connected to a plurality of antenna array elements 121 in an antenna array element group 14. In some embodiments, the multiple beamforming chips 13 and the multiple antenna array element groups 14 are in a one-to-one correspondence and electrically connected, i.e., the number of beamforming chips 13 is equal to the number of antenna array element groups 14.
In some embodiments, as shown in FIG. 1, the antenna module 100 also includes a power division network 15, the power division network 15 is electrically connected to the multiple beamforming chips 13, and the power division network 15 includes multiple power dividers 151 and multiple connecting cables 152.
In the above solution, the multiple beamforming chips 13 and the multiple antenna array element groups 14 are in a one-to-one correspondence, and as the number of channels of the beamforming chips 13 of the current antenna module 100 increases, the difficulty of thermal dissipation increases. To solve this problem, in some embodiments, a sparse array solution is proposed, as shown in FIG. 2. In the antenna module 100, some antenna array elements 121 are removed, so that the antenna array 12 shows a sparse layout, and blank boxes represent the removed antenna array elements 121, while the scale of an active circuit remains unchanged, i.e., the number of beamforming chips 13 is unchanged. The active circuit includes the beamforming chips 13, and the feed connecting lines between the beamforming chips 13 and the antenna array elements 121. The reduction of antenna array elements 121 solves the problem of layout traces in terms of the density, and can solve the problem of thermal dissipation to some extent, while also increasing the aperture area of the antenna, however, some circuits of the active circuit are in a floating state, which diminishes the advantage part of high integration of the beamforming chips 13 and is not conducive to cost reduction.
In some other embodiments, in the antenna module, without changing the size of the antenna array 12, some of the beamforming chips 13 are removed, thereby reducing the cost and power consumption of the 5G millimeter wave antenna module, and solving the problem of thermal dissipation.
FIG. 3A and FIG. 3B are architectural diagrams of an antenna module. As shown in FIG. 3A and FIG. 3B, the antenna module 1000 includes a substrate 11, an antenna array 12, N beamforming chips 13, and a power division network 15. The antenna array 12 includes multiple antenna array elements 121, and the multiple antenna array elements 121 are grouped into M antenna array element groups 14; and each beamforming chip 13 of the N beamforming chips 13 is connected to a plurality of antenna array elements 121 in an antenna array element group 14. Here, M > N.
It should be noted that "141-14" appearing in the drawings of the present disclosure indicates that the indicated component is 141 and belongs to 14, i.e., this component is both 141 and 14, and similar reference signs appearing elsewhere in the drawings of the embodiments of the present disclosure follow the above explanation.
Exemplarily, as shown in FIG. 3A, the antenna array 12 is not a full array, M antenna array element groups 14 are arranged in an array, and the number of antenna array elements 121 included in each antenna array element group varies. For example, the number of antenna array elements 121 included in the antenna array element group 14 may be 6, 7, or 8.
Exemplarily, as shown in FIG. 3B, the antenna array 12 is a full array, the multiple antenna array elements 121 are arranged in an array, and each antenna array element group 14 includes the same number of antenna array elements 121, e.g., each antenna array element group 14 includes eight adjacent antenna array elements 121.
As shown in FIG. 3A, the antenna module 1000 includes thirty-two antenna array element groups 14 and twenty-one beamforming chips 13; as shown in FIG. 3B, the antenna module 1000 includes thirty-two antenna array element groups 14 and twenty-four beamforming chips 13, i.e., the number of antenna array element groups 14 is greater than the number of beamforming chips 13, which is equivalent to removing some of the beamforming chips 13, which solves the problem of thermal dissipation from the perspective of the active circuit, and in some embodiments, the above embodiment may be called a sparse source solution.
It should be noted that whether using the sparse array solution or the sparse source solution, it is necessary to ensure equivalent isotropically radiated power (Equivalent Isotropically Radiated Power, EIRP) of the antenna module to reach a certain level, i.e., it cannot affect the normal operation and normal implemented function of the antenna module.
The principle utilized in the above embodiments to implement the target solution is: a basic principle of "antenna forming is independent of the active feed network" in the 5G millimeter wave beamforming. That is, in the design of the antenna module, the same magnitude of equivalent isotropically radiated power may be achieved by reducing the number of antenna array elements 121, or the same magnitude of equivalent isotropically radiated power may also be achieved by reducing the number of beamforming chips 13. Reducing the number of beamforming chips 13 can not only solve the problem of thermal dissipation, but also can reduce the cost of the product to some extent.
The equivalent isotropically radiated power is also called effective isotropically radiated power (Effective Isotropically Radiated Power, EIRP), means the radiated power of a satellite or ground station in a specified direction. Under ideal states, a calculation formula of the EIRP under a large-scale array is as follows:
EIRP(dBm) = Pave + 10×log(the number of beamforming chips) + 10×log(the number of antenna array elements) + Gain_ANT.
It can be seen that the equivalent isotropically radiated power is related to the number of antenna array elements 121 and the number of beamforming chips 13.
In some embodiments, a quantitative relationship between N and M satisfies that: a difference value between an ideal equivalent isotropically radiated power of the antenna array 12 and an actual equivalent isotropically radiated power of the antenna array 12 is less than or equal to a set value. The ideal equivalent isotropically radiated power of the antenna array 12 is an equivalent isotropically radiated power obtained when the antenna array 12 is controlled by M beamforming chips 13, and the actual equivalent isotropically radiated power of the antenna array 12 is an equivalent isotropically radiated power obtained when the antenna array 12 is controlled by the N beamforming chips 13.
Since M > N, the number of beamforming chips 13 is less than the number of antenna array element groups 14, so some of the antenna array element groups 14 are not adjusted by the beamforming chips 13, and thus the actual equivalent isotropically radiated power of the antenna array 12 has a certain loss, compared to the case of M = N, that is, in the case where the beamforming chips 13 and the antenna array element groups 14 are electrically connected in the one-to-one correspondence, each antenna array element group 14 in the antenna array 12 is adjusted by the corresponding beamforming chip 13, and then the obtained ideal equivalent isotropically radiated power will be higher than the actual equivalent isotropically radiated power. The difference value between the ideal equivalent isotropically radiated power of the antenna array 12 and the actual equivalent isotropically radiated power of the antenna array 12 is limited to be less than or equal to the set value, that is, the reduced value of the actual equivalent isotropically radiated power with respect to the ideal equivalent isotropically radiated power is limited within an acceptable range, which may ensure the equivalent isotropically radiated power of the antenna module still to be guaranteed under the sparse source solution, thereby ensuring the normal operation of the antenna array 12.
In some examples, the set value is from 2 dB to 3 dB.
In some examples, the above-mentioned set value is obtained according to the specification of the TS 38.104 protocol in the 3rd generation partnership project (3rd Generation Partnership Project, 3GPP) specification series, in conjunction with simulation tests of the embodiments of the present disclosure, and in the case where the set value is from 2dB to 3dB, the equivalent isotropically radiated power of the antenna module 1000 can still be guaranteed, and the normal operation of the antenna array 12 can be guaranteed.
In the above embodiments, in the case where the scale size of the antenna array 12 remains unchanged, the number of the beamforming chips 13 is reduced by removing some beamforming chips 13, thereby solving the problem of the difficulty of thermal dissipation of the high-density layout; additionally, since the beamforming chips 13 are saved, the overall cost of the antenna module 100 may be reduced to some extent; moreover, the actual equivalent isotropically radiated power of the antenna array 12 can reach a similar level, so the normal operation of the antenna array 12 can be guaranteed.
To clearly describe this solution, structures, functions, and implementation principles of various components in the antenna module 1000 are described below.
The structure of the above-mentioned antenna module 1000 is shown in FIG. 3B to FIG. 5B. The antenna module 1000 includes: beamforming chips 13, antenna array elements 121, and a power division network 15.
The power division network 15 is electrically connected to the beamforming chips 13, and configured to transmit signals to the beamforming chips 13. Each beamforming chip 13 is electrically connected to a plurality of antenna array elements 121, each beamforming chip 13 has a plurality of transceiver channels connected to the plurality of antenna array elements 121, and the plurality of transceiver channels are connected to the plurality of antenna array elements 121 in the one-to-one correspondence via a plurality of feed lines. The beamforming chip 13 includes functions of the partial power division network, transceiver switches, amplifier(s), and phase shifter(s). The beamforming chip 13 is configured to implement functions of amplitude adjustment and phase adjustment for the antenna array elements 121, and for example, the beamforming chip 13 may control an amplitude and a phase of each channel independently, thereby flexibly adjusting direction, gains, sidelobe levels, EIRP, and other metrics of beams of the antenna array 12.
The principle of beamforming is shown in FIG. 6 to FIG. 10, and beamforming is also called beam forming. The beamforming technology adjusts parameters of basic units of a phase array, to achieve constructive interference for signals in certain angles and destructive interference for signals in other angles. Beamforming may be applied to both a signal transmitting end and a signal receiving end.
FIG. 6 is a schematic diagram of a specific antenna direction in a spherical coordinate system 200, in which θ is defined as an angle between the antenna direction and the z-axis, and Φ is defined as an angle between the antenna direction and the x-axis. In the antenna array 12, multiple antenna array elements 121 are arranged in an array, and a distance between every two adjacent antenna array elements 121 is set as d. As shown in FIG. 7, to achieve beamforming, a phase difference between every adjacent antennas' feed sources must be a fixed value dcosθ. As shown in FIG. 8, phase adjustment may achieve the superposition of the phase of the antenna in a certain direction, thereby improving the gain in the pointed direction of the antenna. As shown in FIG. 9, the distance between two adjacent antennas is d, and typically d is chosen as λ/2, so as to ensure sufficiently low sidelobe levels; and if d is greater than λ/2, sidelobes will rise; if d is less than λ/2, coupling between antenna array elements 121 will be enhanced; as shown in FIG. 10, the beam at 0° and 30° reaches the maximum gain effect.
In some embodiments, as shown in FIG. 5A and FIG. 5B, the plurality of antenna array elements 121 and beamforming chips 13 are located on two sides of the substrate 11 respectively, and exemplarily, the substrate 11 is a printed circuit board (Printed Circuit Board, PCB), the printed circuit board is a multi-layer board, and a plurality of feed lines connecting the antenna array elements 121 and beamforming chips 13 typically need the layer transition via a high density interconnector (High Density Interconnector, HDI) process.
In some embodiments, as shown in FIG. 11A and FIG. 11B, the above-mentioned antenna array elements 121 are configured as patch antennas, and in the 5G millimeter waves, the patch antennas often use slot antennas, and the patch antenna (Patch Antenna) includes a patch, a slot, and a patch feed line. In FIG. 11A, a surface layer is the patch, a second layer is the slot, and a third layer is the feed line. FIG. 11B is a perspective view, showing the patch layer 301, slot layer 302, and feed line layer 303 in sequence from top to bottom, where the slot is shaped like an "I".
The feed line layer 303 comes from the beamforming chip 13, and the beamforming chip 13 is electrically connected to the antenna array elements 121 via the feed lines.
In some embodiments, the power division network 15 includes multiple power dividers 151 and connecting cables 152 (referring to FIG. 1), and exemplarily, the above-mentioned power division network 15 may be a T-junction power division network or a conventional Wilkinson power divider network (as shown in FIG. 13).
A full name of the power divider 151 is Power divider, which is a device that divides energy of one route of an input signal into two or more routes of outputs with equal or unequal energy, and also combines energy of multiple routes of signals into one route of output, in which case it is called a combiner. A power divider should ensure a certain level of isolation between its output ports. Power dividers are categorized typically, by outputs, as one-to-two (one input, two outputs) or one-to-three (one input, three outputs), etc. In the embodiments shown in FIG. 3A and FIG. 3B, the power dividers in the power division network 15 are one-to-two power dividers.
FIG. 12 is a circuit structural diagram of an equal-division one-to-two power divider. The power divider 151 includes: an input line 1511, two routes of 1/4-wavelength impedance transformation lines 1512, two routes of output lines 1513, and an isolation resistor 1514. The input line 1511 is configured with an impedance of Z0; the two routes of 1/4-wavelength impedance transformation lines 1512 are configured with an impedance of $\sqrt{2} \times Z 0$ ; the two routes of output lines 1513 are configured with an impedance of Z0; and the isolation resistor 1514 is configured as 2×Z0.
In some embodiments, as shown in FIG. 13, the power division network includes one input port and multiple output ports. The output ports are electrically connected to the beamforming chips, and an example of the impedance of some structures of the power division network is as follows: the input line 1511 and the output line 1513 have an impedance Z0 of 50 Ω; the isolation resistor 1514 is 100 Ω; and the 1/4-wavelength impedance transformation line 1512 has an impedance of 70.7 Ω.
As an example, as shown in FIG. 3B, in the antenna module 1000, the antenna array element 121 is configured as a dual-polarized antenna array element, and the beamforming chip 13 is configured as a dual-polarized beamforming chip, and the power division network 15 is electrically connected to the N beamforming chips 13. Exemplarily, each output port of the power division network 15 is electrically connected to a beamforming chip 13 respectively; the power division network 15 is configured as a dual-polarized power division network, the solid-line network represents one power division network, and the dashed-line network represents another power division network 15, and these two power division networks 15, as a group of power division networks 15, are two polarized power division networks, and each of the two power division networks includes multiple output ports, and positions of output ports of one power division network correspond one-to-one with positions of output ports of another power division network. Each beamforming chip 13 is electrically connected to the corresponding output port of the two polarized power division networks 15, respectively.
The above contents describe the basic structures of the antenna array elements 121, the beamforming chips 13, and the power division network 15 included in the antenna module 1000, and next, the implementation principle of "achieving the same magnitude of equivalent isotropically radiated power by reducing the number of beamforming chips 13" is described.
Through the simulation analysis, it is found that in the case of a full-array layout of the antenna array 12, a similar level of EIRP may still be achieved, by reducing the number of beamforming chips 13. Taking an 8×8 full array as an example for illustration, the following cases are divided, as shown in FIG. 14 to FIG. 19:

1) a full array;
2) an excitation amplitude of an antenna array element on a corner is less than an ideal excitation amplitude by 10 dB;
3) an excitation amplitude of a certain array element at the center of the array is less than an ideal excitation amplitude by 10 dB;
4) excitation amplitudes of array elements on four corners of the antenna array are less than an ideal excitation amplitude by 10 dB;
5) excitation amplitudes of four antennas at the center of the antenna array are less than an ideal excitation amplitude by 10 dB; and
6) excitation amplitudes of 16 array elements at the center of the antenna array are less than an ideal excitation amplitude by 10 dB.

In FIG. 14 to FIG. 19, the antenna array elements 121 represent antenna array elements normally controlled by the beamforming chips 13, while the antenna array elements 17 represent antenna array elements not controlled by the beamforming chips 13. The antenna array elements 17 not controlled by the beamforming chips 13 are represented by excitation amplitudes with -10 dB errors in the simulation.

By simulating the antenna array for the above cases, results shown in Table 1 are obtained.

Table 1 Simulation results of influences of beamforming amplitude errors on system performance

Error Source	Main Lobe Direction / deg		Main Lobe Power / dBm	Main lobe 3dB lobe width / deg	EVM/%	ACPR/dBc
Error Source	Theta	Phi	Main Lobe Power / dBm	Main lobe 3dB lobe width / deg	EVM/%	lower	upper
No error (full array)	31	45	54.74	15	3.5587	34.695	33.368
Amplitude error of a certain array element on a corner	31	45	54.68	15	3.5465	34.668	33.34
-10dB
Amplitude error of a certain array element at the center	31	45	54.66	15	3.5465	34.669	33.341
-10dB
Amplitude errors of four array elements on corners	31	45	54.51	15	3.5465	34.668	33.341
-10dB
Amplitude errors of four array elements at the center	31	45	54.41	14	3.5465	34.668	33.341
-10dB
Amplitude errors of 16 array elements at the center	31	45	53.25	13	3.5465	34.668	33.34
-10dB

From Table 1, it can be seen that when there are excitation amplitude errors of antenna array elements in beamforming, the following conclusions are obtained.

1. There is basically no impact on a system EVM (Error Vector Magnitude, error vector amplitude) and an ACPR (Adjacent Channel Power Ratio).

The error vector (a vector including amplitude and phase) is a vector difference between an ideal error-free reference signal and an actual transmission signal at a given time instant, which can comprehensively measure the amplitude error and phase error of the modulated signal; the error vector magnitude (EVM) is defined as a ratio of a root mean square value of average power of an error vector signal to a root mean square value of average power of an ideal signal, and is expressed in the form of percentage. The smaller the EVM is, the better the signal quality is.
The adjacent channel power ratio (ACPR) refers to a ratio of average power of an adjacent frequency channel and average power of a currently used channel; the adjacent channel power ratio is a commonly used metric that measures the linearity of the transmission system, which may be used to describe characteristics of signal out-of- band spectrum distortion caused by nonlinear distortion of the power amplifier, that is, the degree of the main power leakage into the adjacent frequency channel. In actual usages, the measurement is often simplified by measuring third order intermodulation (Third Order Intermodulation, IMD3) of the current output signal.
2. In a case where 1/4 of antenna array elements at the center of the antenna array 12 is invalid, the EIRP loss is 1.49 (dB), that is, a difference between main lobe power obtained with the full array and main lobe power obtained with amplitude errors of -10 dB for the center sixteen array elements is 54.74-53.25=1.49 (dB).
3. In different cases, there will be a certain offset in the beam direction, and as the number of array elements with the excitation amplitude less than the ideal excitation amplitude increases, the power of the main lobe has a trend to decrease, but the impact is not very obvious.
The following calculations are used to argue "achieving the same magnitude of equivalent isotropically radiated power by reducing the number of beamforming chips 13".
A calculation formula for EIRP may be expressed as the following formula.
EIRP(dBm) = Pave + 10 × log(the number of beamforming chips) + 10 × log(the number of antenna array elements) + Gain_ANT.
In the above formula, a final unit of EIRP is dBm, but the final result cannot be obtained by directly adding the logarithmic power, so in order to explain this problem, the corresponding value can be quantified to clarify the theoretical basis.
The following is refined according to the output power level of the common beamforming chip and the scale of array elements in the simulation diagram:

1. the linear output power Pave of the channel is calculated according to 11.6 dBm;
2. the number of beamforming chips of the full array is calculated according to 64;
3. antenna array elements of the full array are defined as 64; and
4. a gain Gain_ANT of antenna array elements is calculated according to 7 dB.

The above parameters may be calculated by bringing them into the calculation formula of EIRP, to obtain the following results:

in a case where the antenna array is a full array (8×8) and all the antenna array elements are controlled by the beamforming chips, the calculated EIRP of the antenna array is 54.72 dBm; and
in a case where the antenna array is a full array (8×8) and the excitation of 16 antenna array elements at the center is adjusted to -50 dBm (simulating a case where the 16 array elements at the center have no excitation), i. e., the 16 antenna array elements are not controlled by the beamforming chips, the calculated EIRP of the antenna array is 53.47 dBm.

It can be seen that, by comparing the case where the 16 antenna array elements at the center of the antenna array 12 are not controlled by the beamforming chips with the case where the full array of the antenna array is all controlled by the beamforming chips, a difference in the EIRP between the two cases is 1.25 dB.
From the above simulation and the calculated results, the same magnitude of the equivalent isotropically radiated power may be achieved by reducing the number of beamforming chips, that is, the sparse source solution mentioned in the above embodiments, with ensuring the scale of the antenna array 12 to be unchanged, can achieve the reduction in cost and solve the problem of thermal dissipation under the premise of ensuring to achieve the same magnitude of the equivalent isotropically radiated power, by reducing the number of beamforming chips. Some embodiments of the arrangement of the beamforming chips 13 and the antenna array element groups 14 in the antenna module 1000 are described below.
In some embodiments, as shown in FIG. 3B, among the above-mentioned antenna array element groups 14, antenna array element groups 14 connected to the beamforming chips 13 are first antenna array element groups 141, and antenna array element groups 14 other than the first antenna array element groups 141 are second antenna array element groups 142, that is, a plurality of antenna array elements 121 in the second antenna array element group 142 is not controlled by the beamforming chip 13, and the second antenna array element groups 142 are not connected to the corresponding beamforming chips 13.
It should be noted that the plurality of antenna array elements 121 in the second antenna array element group 142 may be subject to mutual coupling by antenna array elements 121 in the first antenna array element group 141 adjacent to this second antenna array element group, thereby generating a certain gain.
A number of antenna array element groups 14 adjacent to at least one of the second antenna array element groups 142 in row direction X and column direction Y is greater than or equal to a number of antenna array element groups 14 adjacent to any one of the first antenna array element groups 141 in the row direction X and the column direction Y, and the row direction X and column direction Y are row direction and column direction in which the multiple antenna array elements 121 are arranged. The number of antenna array element groups 14 adjacent to an antenna array element group 14 in the row direction X and column direction Y refers to a sum of a number of antenna array element groups 14 adjacent to this antenna array element group 14 in the row direction X and a number of antenna array element groups 14 adjacent to this antenna array element group 14 in the column direction Y.
As shown in FIG. 3B, taking the second antenna array element group 142 located in the middle position of the antenna array 12 as an example, the number D1 of antenna array element groups 14 adjacent to the second antenna array element group 142 in the row direction X and the column direction Y is 4; and taking the first antenna array element group 141 located in the middle position of the antenna array 12 as an example, the number D2 of antenna array element groups 14 adjacent to the first antenna array element group 141 in the row direction X and the column direction Y is 4, and D1 and D2 are equal. Taking the first antenna array element group 141 located on a lower right corner position of the antenna array 12 as an example, the number D3 of antenna array element groups 14 adjacent to the first antenna array element group 141 in the row direction X and the column direction Y is 2, and D1 is greater than D3.
That is, at least one of the second antenna array element groups 142 is located in the middle position of the antenna array 12, and each of the second antenna array element groups 142 has at least three adjacent antenna array element groups 14 in the row direction X and the column direction Y.
In the above embodiments, in order to solve the problem of thermal dissipation, a setting principle of the position of the beamforming chips 13 in the antenna array 12 is that no beamforming chip 13 is set in an area with high thermal density, that is, no beamforming chip 13 is set in an area in which the chips are relatively dense. However, the middle position of the antenna array 12 is an area with high thermal density, and based on the above setting principle, at least one of the second antenna array element groups 142 is located in the middle position of the antenna array 12, which can provide thermal dissipation effect to a greater extent, so as to achieve a win-win situation in terms of the cost reduction and the thermal requirement.
Moreover, since a plurality of antenna array elements 121 in the second antenna array element group 142 may be subject to mutual coupling by antenna array elements 121 in the adjacent first antenna array element group 141, thereby generating a certain gain, and the second antenna array element group 142 is located in the middle position, so that even if the beamforming chip 13 corresponding to the second antenna array element group 142 is removed, the second antenna array element group 142 may generate a gain in the effect of the surrounding first antenna array element group 141, thereby enabling the overall EIRP of the antenna array 12 to reach a similar level to the case of the full array and no beamforming chip 13 deleted.
In some examples, as shown in FIG. 3B, at least one of the first antenna array element groups 141 exists between any two of the second antenna array element groups 142 along the row direction X and the column direction Y
Exemplarily, multiple antenna array element groups 14 that the antenna array 12 is divided into, are arranged in four rows and eight columns, and among a first row of antenna array element groups 141, there are two first antenna array element groups 141 between two second antenna array element groups 142 along the row direction X; and among a second column of antenna array element groups 142, there is one first antenna array element group 141 between two second antenna array element groups 142 along the column direction Y. That is, any two of the second antenna array element groups 142 are not adjacent to each other, and this setting enables as many of the second antenna array element groups 142 as possible to be subject to mutual coupling by the surrounding first antenna array element group 141, thereby generating a similar gain.
In some embodiments, on the premise of N and M satisfying that the difference value between the actual equivalent isotropically radiated power of the antenna array 12 and the ideal equivalent isotropically radiated power of the antenna array 12 is less than or equal to the set value, the quantitative relationship between N and M may be: $\frac{3}{5} M \leq$ $N \leq \frac{7}{8} M .$
To better understand the above-mentioned quantitative relationship of N and M, several examples corresponding to $N = \frac{3}{4} M$ or $N = \frac{7}{8} M$ are provided respectively below.
In some examples, as shown in FIG. 20 and FIG. 21, the antenna array 12 includes multiple antenna array element group units 16, and each of the antenna array element group units 16 includes four adjacent antenna array element groups 14; among the four antenna array element groups 14 of each antenna array element group unit 16, three antenna array element groups 14 of the four antenna array element groups belong to the first antenna array element groups 141, and remaining one antenna array element groups 14 of the four antenna array element groups belongs to the second antenna array element groups 142.
In FIG. 20 and FIG. 21, the white boxes indicate the removed beamforming chips 13, and in the antenna array 12, every four adjacent antenna array element groups 14 are grouped as an antenna array element group unit 16. Exemplarily, eight antenna array element group units 16 are included in the antenna array 12, and in an antenna array element group unit 16, three antenna array element groups 14 belong to the first antenna array element groups 141, and one antenna array element group 14 belongs to the second antenna array element groups 142, i.e., in each antenna array element group unit 16, a beamforming chip 13 corresponding to one antenna array element group 14 is removed, and there is no limitation on the position of the removed beamforming chip 13, and in some examples, the above-mentioned setting principle of the position of the beamforming chip 13 in the antenna array 12 is satisfied.
The above solution is the embodiment corresponding to $N = \frac{3}{4} M$ . FIG. 20 and FIG. 21 only give two exemplary combining ways of the set position of the N beamforming chips 13, and there are a variety of other solutions for the set position of the N beamforming chips 13, all of which fall within the scope of this embodiment covered herein.
In the above embodiment, 1/4 of the beamforming chip 13 is removed in the antenna module 1000, so that $N = \frac{3}{4} M$ , which may substantially solve the problem of thermal dissipation of the antenna board in a case of a decrease in EIRP of about 1.5 dB, and is applicable for a case where the antenna module has a relatively high thermal dissipation pressure.
In some examples, as shown in FIG. 22 and FIG. 23, the antenna array 12 includes multiple antenna array element group units 16, and each of the antenna array element group units 16 includes eight adjacent antenna array element groups 14; among the eight antenna array element groups 14 in each antenna array element group unit 16, seven antenna array element groups 14 of the eight antenna array element groups belong to the first antenna array element groups 141, and remaining one antenna array element group 14 of the eight antenna array element groups belongs to the second antenna array element groups 142.
In FIG. 22 and FIG. 23, white boxes indicate the removed beamforming chips 13, and in the antenna array 12, every eight adjacent antenna array element groups 14 is grouped into an antenna array element group unit 16. Exemplarily, the antenna array 12 includes four antenna array element group units 16, and in an antenna array element group unit 16, seven antenna array element groups 14 belong to the first antenna array element groups 141, and one antenna array element group 14 belongs to the second antenna array element groups 142, i.e., in each antenna array element group unit 16, a beamforming chip 13 corresponding to one antenna array element group 14 is removed, and there is no limitation on the position of the removed beamforming chip 13, and in some examples, the above-mentioned setting principle of the position of the beamforming chip 13 in the antenna array 12 is satisfied.
The above solution is the embodiment corresponding to $N = \frac{7}{8} M$ . FIG. 22 and FIG. 23 only give two exemplary combining ways of the set position of the N beamforming chips 13, and there are a variety of other solutions for the set position of the N beamforming chips 13, all of which fall within the scope of this embodiment covered herein.
In the above embodiment, 1/8 of the beamforming chips 13 are removed in the antenna module 1000, so that $N = \frac{7}{8} M$ , and in this way, only a smaller number of beamforming chips 13 need to be removed to solve the problem of thermal dissipation well, and the level of the EIRP of the antenna array 12 is higher in this embodiment.
The above two embodiments are only typical forms of the sparse source solution, and all the other embodiments fall within the scope of the sparse source as long as the number of beamforming chips 13 is less than the number of antenna array element groups 14, the present disclosure is not limited to the above embodiments.
The amount of reduction of the beamforming chips 13 needs to be determined based on the degree of reduction of the system EIRP. Exemplarily, in addition to the cases of removing 1/4 of the beamforming chips 13 and removing 1/8 of the beamforming chips 13 in the antenna module 1000 as described in the above embodiments, in the case of the above-mentioned scale of the array, if the EIRP is allowed to be reduced by 1.8 dB with respect to the EIRP under the full array, 1/3 of the number of the beamforming chips 13 may also be removed with the full array, and in this case, $N = \frac{2}{3} M$ ; if the EIRP is allowed to drop by 2.2 dB in the case of the scale of the array, 2/5 of the number of beamforming chips 13 may be removed, and in this case, $N = \frac{3}{5} M$ . Both 1.8 dB and 2.2 dB are less than the set value.
In the antenna module 1000 provided in some embodiments of the present disclosure, in the case where the number of antenna array elements 121 in the antenna array 12 remains unchanged, some of the active components are removed, so that the number of beamforming chips 13 is reduced, thereby solving the problem of the difficulty of thermal dissipation in the high-density layout on the premise of ensuring the same level of the EIRP, while the cost of the whole machine is enabled to be reduced to a certain extent.
Moreover, the substrate 11 in the antenna module is a printed circuit board, and the reduction of the number of active components frees up more space for traces in the beamforming architecture, so that the interconnection process of the traces of the printed circuit board is no longer restricted, which reduces the development cost of the printed circuit board, thereby improving the competitiveness of the product.
Some embodiments of the present disclosure also propose a communication device 500, as shown in FIG. 24. The communication device 500 mainly relates to an active antenna unit (Active Antenna Unit, AAU) product for a base station in the field of communications, and in some examples, the communication device 500 includes: an antenna module 1000, a radio frequency unit 2000, and a housing 3000. The above-mentioned antenna module 1000 and radio frequency unit 2000 are disposed within the housing 3000, and the radio frequency unit 2000 is connected to the antenna module 1000. When the communication device 500 is in operation, the radio frequency unit 2000 transmits a signal to the antenna module 1000 via the input port 153 of the power division network 15 (as shown in FIG. 20 to FIG. 23), thereby accomplishing a communication function with the outside.
The foregoing is only the specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any changes or substitutions within the scope of the technology disclosed in the present disclosure should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be determined based on the protection scope of claims.

Claims

An antenna module, characterized by comprising:
an antenna array, wherein the antenna array comprises multiple antenna array elements, and the multiple antenna array elements are grouped into M antenna array element groups; and

N beamforming chips, wherein each of the beamforming chips is connected to a plurality of antenna array elements in an antenna array element group;

wherein M > N, and both M and N are positive integers.
The antenna module according to claim 1, wherein:
the M antenna array element groups are arranged in an array;

among the M antenna array element groups, antenna array element groups connected to the beamforming chips are first antenna array element groups, and antenna array element groups other than the first antenna array element groups are second antenna array element groups; and

a number of antenna array element groups adjacent to at least one of the second antenna array element groups in row direction and column direction is greater than or equal to a number of antenna array element groups adjacent to any one of the first antenna array element groups in the row direction and the column direction, and the row direction and the column direction are row direction and column direction in which the M antenna array element groups are arranged.
The antenna module according to claim 2, wherein along the row direction or the column direction, at least one of the first antenna array element groups exists between any two of the second antenna array element groups.
The antenna module according to claim 2 or 3, wherein:
a quantitative relationship between N and M satisfies that:
a difference value between an ideal equivalent isotropically radiated power of the antenna array and an actual equivalent isotropically radiated power of the antenna array is less than or equal to a set value;

wherein the ideal equivalent isotropically radiated power of the antenna array is an equivalent isotropically radiated power obtained when the antenna array is controlled by M beamforming chips, and the actual equivalent isotropically radiated power of the antenna array is an equivalent isotropically radiated power obtained when the antenna array is controlled by the N beamforming chips.
The antenna module according to claim 4, wherein the set value is 2 dB to 3 dB.
The antenna module according to claim 5, wherein:
the quantitative relationship between N and M is $\frac{3}{5} M \leq N \leq \frac{7}{8} M$ .
The antenna module according to claim 6, wherein when $N = \frac{3}{4} M$ :
the antenna array comprises multiple antenna array element group units, each of the antenna array element group units comprises adjacent four antenna array element groups; and

among the four antenna array element groups in the each antenna array element group unit, three antenna array element groups of the four antenna array element groups belong to the first antenna array element groups, and remaining one antenna array element group of the four antenna array element groups belongs to the second antenna array element groups.
The antenna module according to claim 6, wherein when $N = \frac{7}{8} M$ :
the antenna array comprises multiple antenna array element group units, each of the antenna array element group units comprises adjacent eight antenna array element groups; and

among eight antenna array element groups in the each antenna array element group unit, seven antenna array element groups of the eight antenna array element groups belong to the first antenna array element groups, and remaining one antenna array element group of the eight antenna array element groups belongs to the second antenna array element groups.
The antenna module according to any one of claims 1 to 3, wherein the antenna array element is configured as a dual-polarized antenna array element; the beamforming chip is configured as a dual-polarized beamforming chip; and
the antenna module further comprises a power division network, the power division network is electrically connected to the N beamforming chips respectively, and the power division network is configured as a dual-polarized power division network.
A communication device, characterized by comprising the antenna module according to any one of claims 1 to 9.