Ultra-wideband low-profile extensible DBF array antenna and implementation method thereof

Abstract

The invention discloses an ultra-wideband low-profile extensible DBF array antenna and an implementation method thereof. The array antenna comprises a 4 * 4 array antenna module; the radio frequency front end module is connected with the array antenna module; the radio frequency front-end module comprises four groups of integrated packaging modules, and each group of integrated packaging modules is connected with four array antennas; the integrated packaging module comprises an amplitude-phase multifunctional chip, an up-down conversion chip, an ADC / DA chip, a PA / LNA and a switch chip. And the multilayer printed circuit is connected with the radio frequency front-end module. According to the invention, a mounting mode of grid array packaging is adopted, vertical interconnection between the antenna and the T / R assembly is realized, and the antenna has the advantages of fast assembling speed, low cost and strong expansibility. Meanwhile, the design significantly reduces the size of the antenna, reduces the manufacturing cost, and greatly reduces the insertion loss in signal transmission. In addition, an extensible digital interface is adopted, design and extension of a digital processing multilayer board are facilitated, and adaptability and flexibility of the system are further improved.

Description

Technical Field

[0001] The present invention relates to the field of radar and communication technology, and in particular to an ultra-wideband low-profile expandable DBF array antenna and a realization method thereof. Background Art

[0002] With the rapid development of radar, communication and electronic warfare technologies, the demand for antenna systems in terms of wide-band coverage, low insertion loss, high efficiency and modular design has become increasingly urgent. However, existing technologies still face the following challenges:

[0003] 1. The interconnection between traditional antennas and T / R components usually uses coaxial cables, welding or complex feeding networks. This method is easily limited by accuracy and consistency during the assembly process, resulting in low assembly efficiency. At the same time, the signal transmission path of coaxial cables and feeding networks is long, which will introduce large insertion loss and reflection loss, directly affecting the performance of the system. In addition, the mechanical structure of traditional interconnection methods is complex, which not only occupies a large space, but also limits the miniaturization design of antenna systems, especially in modern high-frequency radar and communication systems. It cannot meet the compact requirements.

[0004] 2. In order to achieve ultra-wideband performance and high gain, antenna design often requires the introduction of multi-layer feeding networks or complex loading structures, which significantly increases the size and weight of the antenna and makes it difficult to meet the needs of portable or compact devices. At the same time, the complexity of connecting the antenna to the T / R components also increases the manufacturing and assembly costs, affecting the large-scale application of the system.

[0005] 3. Currently, most antenna systems use dedicated designs with poor scalability and adaptability, making it difficult to quickly adjust or upgrade to meet the needs of different scenarios. The closed design of the digital signal interface limits the efficient connection between the antenna system and the multi-layer digital processing board, increasing the design complexity of the signal processing system. Summary of the invention

[0006] In order to solve the problems existing in the above-mentioned prior art, the technical solution provided by the present invention includes:

[0007] An ultra-wideband low-profile scalable DBF array antenna, comprising:

[0008] 4×4 array antenna module;

[0009] A radio frequency front-end module connected to the array antenna module; the radio frequency front-end module includes four groups of integrated packaging modules, each group of integrated packaging modules is connected to four array antennas; the integrated packaging module includes an amplitude and phase multifunctional chip, an up and down frequency conversion chip, an ADC / DA chip, a PA / LNA and a switch chip;

[0010] A multi-layer printed circuit connected to the RF front-end module.

[0011] Preferably, it includes:

[0012] Make an array antenna module with a 4×4 cross-dipole array arrangement;

[0013] Mounting four sets of integrated packaging modules on the RF front-end module substrate through a first ball grid array package, and connecting the array antenna module and the RF front-end module through a quasi-coaxial structure;

[0014] A multilayer printed circuit is manufactured, and the printed circuit substrate is connected to the radio frequency front-end module through a second ball grid array.

[0015] Preferably, the array antenna module array spacing is 8.5mm×8.5mm.

[0016] Preferably, the quasi-coaxial structure is a 5-ball grid array, wherein the central solder ball is used for signal transmission and the surrounding 4 solder balls are used for grounding.

[0017] Preferably, the amplitude and phase multifunctional chip, up and down conversion chip, ADC / DA chip, PA / LNA and switch chip are mounted on the RF front-end module substrate through a first ball grid array packaging method, and are packaged into a RF front-end module in a ball grid array mounting form through an electromagnetic compatibility packaging shell.

[0018] Preferably, a keep-out area is provided between the RF front-end module and the printed circuit substrate, and the bottom of the RF front-end module in the keep-out area is in direct contact with the heat dissipation layer of the printed circuit substrate.

[0019] Preferably, the modules are connected via an improved ground-signal-ground wiring similar to a coplanar waveguide to improve the integrity and electromagnetic compatibility of radio frequency signal transmission.

[0020] Beneficial Effects

[0021] The present invention adopts the mounting method of grid array packaging to realize the vertical interconnection between the antenna and the T / R component, which has the advantages of fast assembly speed, low cost and strong scalability. At the same time, the design significantly reduces the size of the antenna, reduces the manufacturing cost, and greatly reduces the insertion loss in signal transmission. In addition, the present invention adopts an expandable digital interface, which facilitates the design and expansion of digital processing multilayer boards, further improving the adaptability and flexibility of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a simulation of a 4×4 array antenna module in a preferred embodiment of the present invention;

[0023] Figure 2 A schematic diagram of antenna unit simulation in a preferred embodiment of the present invention;

[0024] Figure 3It is a schematic diagram of the principle of a radio frequency front-end module in a preferred embodiment of the present invention;

[0025] Figure 4 It is a schematic diagram of the principle of an integrated package antenna AIP in a preferred embodiment of the present invention;

[0026] Figure 5 It is a schematic diagram of vertical interconnection between a fur button and an antenna in the prior art;

[0027] Figure 6 A schematic diagram of a three-dimensional model of an integrated packaging module in a preferred embodiment of the present invention;

[0028] Figure 7 A schematic diagram of the integrated packaging module chip layout in a preferred embodiment of the present invention;

[0029] Figure 8 A schematic diagram of a BGA ball implantation disposed at the bottom of an integrated packaging module in a preferred embodiment of the present invention;

[0030] Fig. 9 A three-dimensional schematic diagram of a package in which an integrated packaging module in a preferred embodiment of the present invention is mounted on a RF front-end module substrate;

[0031] Fig.10 A schematic diagram of a 5-ball grid array (5BGA)-like coaxial structure in a preferred embodiment of the present invention;

[0032] Fig.11 A schematic diagram of the stacking of the bottom of the radio frequency front-end module in a preferred embodiment of the present invention;

[0033] Fig.12 A schematic diagram of a circular array arrangement in another preferred embodiment of the present invention;

[0034] Fig.13 It is a schematic diagram of the gain characteristic curve in a single pulse angle measurement application in another preferred embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described below in conjunction with the accompanying drawings. In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention.

[0036] Embodiment 1

[0037] DBF (Digital Beamforming) is an antenna beam control method based on digital signal processing. By digitally processing the signals received by each unit in the antenna array, this technology can dynamically adjust the amplitude and phase of the signal to achieve the desired beam pointing or radiation characteristics. Based on this technical framework, the present invention has made innovative improvements and applications.

[0038] This embodiment provides an ultra-wideband low-profile scalable DBF array antenna, including:

[0039] 4×4 array antenna module, such as Figure 1 As shown in Figure 1, the design of the antenna unit depends on the target operating frequency band and performance requirements. For example, within the operating frequency band of 12 GHz to 18 GHz, the unit simulation results are as follows: Figure 2 The present invention adopts a rectangular grid array, and the condition for not generating grating lobes in the scanning state is:

[0040] Wherein, d is the array spacing; λ is the wavelength of the working signal, λ=c / f=16.7 mm, c is the speed of light, and f is the working frequency; θ is the scanning angle of the beam, and in the present invention, a single beam full array θ=60° must be satisfied.

[0041] By using the above formula, we can calculate that d<0.536λ≈8.93mm. After considering the engineering margin, the array spacing is 8.5mm×8.5mm.

[0042] Furthermore, to achieve vertical and horizontal dual polarization, the present invention adopts a cross-dipole array design to improve polarization flexibility and coverage.

[0043] A radio frequency front-end module connected to the array antenna module; such as Figure 3 As shown, the RF front-end module includes four groups of integrated packaging modules, each group of integrated packaging modules is connected to four array antennas; the integrated packaging module (System-in-Package, SIP) includes the following main components: amplitude and phase multifunctional chip, up and down conversion chip, ADC / DA chip, PA / LNA and switch chip. Among them, the RF front-end module.

[0044] A multi-layer printed circuit connected to the RF front-end module.

[0045] The above modules are electrically connected through a multi-layer PCB and packaged to form an integrated package antenna (Antenna-in-Package, AIP). Its working principle is as follows Figure 4As shown, it is specifically composed of four groups of SIPs and 16 units (32 channels of dual polarization, supporting time-sharing operation, 16 channels of T / R components each, and 32 channels of antenna). The up and down frequency conversion adopts a multifunctional frequency conversion chip for transmitting and receiving frequency conversion. The AIP provided by the present invention supports external frequency synthesis as the local oscillator for up and down frequency conversion, and all active devices support 5V DC power supply. All chips are low-power applications, and the heat conduction of the substrate meets the junction temperature requirements of the active chips.

[0046] Embodiment 2

[0047] This embodiment is developed on the basis of the above-mentioned embodiment 1, and further optimizes and provides a method for realizing an ultra-wideband, low-profile, and scalable DBF array antenna, which specifically includes:

[0048] An array antenna module with a 4×4 cross-dipole array is manufactured to achieve dual-polarization function and broadband coverage.

[0049] The four groups of integrated packaging modules are mounted on the RF front-end module substrate through the first ball grid array package, and the array antenna module and the RF front-end module are connected through a quasi-coaxial structure.

[0050] Those skilled in the art should know that the integration of traditional antenna feed and its T / R components (Transmit / Receive components, which refer to modules used to implement signal transmission (Transmit) and reception (Receive) functions in radio frequency systems) is currently mostly achieved by directly connecting radio frequency connectors. This connection method results in insertion loss and low interconnection reliability. For example, the use of a wool button form (such as Figure 5 As shown). It is common for connector failure to occur during the assembly process, and it is quite troublesome to change the connector failure, and the maintainability is poor. Therefore, the present invention considers using a feeder interconnection method to greatly reduce the insertion loss, and under the same indicator architecture, it can also effectively reduce the size of the antenna. The specific implementation method is to use a ball grid array (BGA) packaging method, and by arranging a spherical solder joint (solder ball) array, the electrical connection and mechanical fixation between the chip and the circuit board are realized.

[0051] The SIP (integrated package module) designed by the present invention is as follows Figure 6 As shown, the chip layout is as follows Figure 7 By setting a first ball grid array package (such as Figure 8 As shown) mounted on the RF front-end module substrate, such as Fig. 9 Furthermore, in order to imitate the shielding characteristics of the coaxial cable and better shield the radio frequency signal, the present invention adopts a 5-ball grid array (5BGA) for connection, such as Fig.10As shown, the central solder ball is used for signal transmission, and the surrounding four solder balls are used for grounding. Furthermore, in order to improve the integrity and electromagnetic compatibility of RF signal transmission, the RF wiring is connected through an improved ground-signal-ground (GSG) wiring similar to coplanar waveguide (CPW).

[0052] A multilayer printed circuit board (PCB) is manufactured, and the printed circuit board and the RF front-end module are connected through a second ball grid array. In some preferred embodiments, the stacking diagram at the bottom of the RF front-end module is as follows: Fig.11 As shown, a forbidden area is set between the RF front-end module and the printed circuit substrate, and the bottom of the RF front-end module in the forbidden area is in direct contact with the heat dissipation layer of the printed circuit substrate. The forbidden area is to meet the requirements of electromagnetic compatibility (EMC), heat dissipation requirements and mechanical design, specifically referring to the prohibition of arranging wires, pads or signal traces in specific areas of the PCB. These areas are usually designed to solve electromagnetic interference (EMI), thermal management or mechanical support problems. The forbidden area in this embodiment plays a role in RF signal transmission, heat dissipation, EMC and mechanical structure protection, and optimizes system performance and reliability.

[0053] In some other preferred embodiments, specific packaging examples of the RF front-end module are given, and the amplitude and phase multifunctional chip, up and down conversion chip, ADC / DA chip, PA / LNA and switch chip are mounted on the RF front-end module substrate through a first ball grid array packaging method, and are packaged into a ball grid array mounted RF front-end module through an electromagnetic compatibility (EMC) packaging shell.

[0054] Embodiment 3

[0055] This embodiment is developed on the basis of the above-mentioned embodiments 1 and 2, and this embodiment provides an example of the present invention at the application level.

[0056] like Fig.12 As shown, the present invention can adopt a circular array solution to achieve the following typical applications.

[0057] 1. Single pulse angle measurement application: adopt the single pulse angle measurement method of sum and difference ratio, and realize amplitude and phase control through DBF. Its gain characteristic curve is as follows: Fig.13 shown.

[0058] 2. Airborne main tracking radar: It adopts phase scanning working mode, controls beam pointing through phase scanning, and realizes efficient target scanning and tracking functions.

[0059] 3. Multi-beam application: The back-end uses digital signal processing (DSP) technology to complete the generation and control of multi-beams at the back-end (baseband signal processing unit) of the radar or communication system, supporting simultaneous detection and tracking of multiple targets, supporting wide-band operation, and covering multiple frequency bands to meet the needs of different tasks (such as long-range detection, high-resolution imaging, etc.). The combination of multi-beam amplitude and phase control and wide-band performance enables the system to flexibly adjust the beam direction, number and shape in the digital domain while ensuring the high precision and stability of the beam.

[0060] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An ultra-wideband low-profile scalable DBF array antenna, characterized in that: include: 4×4 array antenna module; A radio frequency front-end module connected to the array antenna module; The RF front-end module includes four groups of integrated packaging modules, each group of integrated packaging modules is connected to four array antennas; the integrated packaging modules include amplitude and phase multifunctional chips, up and down frequency conversion chips, ADC / DA chips, PA / LNA and switch chips; A multi-layer printed circuit connected to the RF front-end module.

2. The method for implementing the ultra-wideband low-profile scalable DBF array antenna according to claim 1, characterized in that: include: Make an array antenna module with a 4×4 cross-dipole array arrangement; Mounting four sets of integrated packaging modules on the RF front-end module substrate through a first ball grid array package, and connecting the array antenna module and the RF front-end module through a quasi-coaxial structure; A multilayer printed circuit is manufactured, and the printed circuit substrate is connected to the radio frequency front-end module through a second ball grid array.

3. The method for realizing the ultra-wideband low-profile scalable DBF array antenna according to claim 2, characterized in that: The array antenna module array spacing is 8.5mm×8.5mm.

4. The method for realizing the ultra-wideband low-profile scalable DBF array antenna according to claim 2, characterized in that: The quasi-coaxial structure is a 5-ball grid array, wherein the central solder ball is used for signal transmission and the surrounding 4 solder balls are used for grounding.

5. The method for realizing the ultra-wideband low-profile scalable DBF array antenna according to claim 2, characterized in that: The amplitude and phase multifunctional chip, up and down conversion chip, ADC / DA chip, PA / LNA and switch chip are mounted on the RF front-end module substrate through the first ball grid array packaging method, and are packaged into a RF front-end module in the form of a ball grid array mounting through an electromagnetic compatibility packaging shell.

6. The method for realizing the ultra-wideband low-profile scalable DBF array antenna according to claim 2, characterized in that: A forbidden area is arranged between the radio frequency front-end module and the printed circuit substrate, and the bottom of the radio frequency front-end module in the forbidden area is in direct contact with the heat dissipation layer of the printed circuit substrate.

7. The method for realizing the ultra-wideband low-profile scalable DBF array antenna according to claim 2, characterized in that: The modules are connected through improved ground-signal-ground wiring similar to coplanar waveguide to improve the integrity and electromagnetic compatibility of RF signal transmission.

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