A phased array chip layout method supporting multi-band common aperture

Abstract

This invention discloses a phased array chip layout method supporting multiple frequency bands sharing the same aperture, belonging to the field of phased array antenna layout technology. The invention includes: determining multiple frequency bands; designing a multi-layer substrate, with low-frequency antennas on the upper layer and high-frequency antennas on the lower layer, vertically overlapping and sharing the same aperture; deploying corresponding frequency band transceiver chips on the back of each layer; setting frequency selection surface isolation mutual coupling between layers; and laminating to form modules. This invention enables multiple frequency bands to share the same physical aperture, saving more than 60% of area; by optimizing the stacked structure and isolation layers, the performance of each frequency band antenna is close to that of an independently designed antenna; the transceiver chips are directly deployed on the back of the corresponding layer, shortening feed lines and reducing losses; and it can be prefabricated as an independent module, facilitating mobile phone integration. This invention is applicable to the integration of multi-band satellite communication phased array antennas in mobile terminals such as mobile phones.

Description

Technical Field

[0001] This invention relates to the field of phased array antenna layout technology, and more specifically to a phased array chip layout method that supports multiple frequency bands sharing the same aperture. In particular, it is a layout method that uses a multi-layer substrate design to enable antenna elements of different frequency bands to share the same physical aperture, while integrating transceiver chips of the corresponding frequency bands, thereby reducing the area occupied. Background Technology

[0002] With the development of direct satellite communication technology for mobile phones, mobile terminals need to be compatible with multiple satellite constellations. Different constellations typically operate in different frequency bands, such as the S-band (2 to 4 GHz), Ku-band (12 to 18 GHz), and Ka-band (26.5 to 40 GHz). Traditional solutions involve designing a separate phased array antenna for each frequency band, which requires multiple independent physical areas. However, smartphones have highly integrated internal spaces, with components such as the motherboard, battery, and camera already occupying most of the space. Independent layout for multiple frequency bands would lead to insufficient space, making miniaturization and integration impossible.

[0003] While co-aperture antenna technology allows multiple frequency bands to share the same physical aperture, existing designs are mostly geared towards passive antennas and do not consider the layout adaptation of active transceiver chips. Transceiver chips for different frequency bands require different manufacturing processes, resulting in differences in size, power consumption, and interface types. Achieving efficient interconnection between multi-band chips and antennas within a co-aperture area, while simultaneously suppressing cross-coupling interference between frequency bands, has become a key challenge restricting the integration of multi-band phased arrays. Existing layout methods either neglect the collaborative design of chips and antennas, leading to significant signal loss, or lack effective frequency band isolation measures, causing mutual interference in the performance of each frequency band, making it difficult to meet the comprehensive requirements of mobile terminals for space, performance, and compatibility. Therefore, a novel multi-band co-aperture phased array chip layout method is urgently needed to achieve integrated antenna and chip design. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problems of insufficient layout space for multi-band phased arrays in mobile terminals, severe frequency band mutual coupling interference, and poor chip-antenna coordination, and to provide a phased array chip layout method that supports multiple frequency bands with the same aperture.

[0005] The core of the layout method of this invention is to achieve efficient integration of multi-band antennas and chips through multi-layer substrate stacking and common aperture design. The specific steps are as follows: The first step is to identify the multiple operating frequency bands that need to be integrated, and sort them from low to high frequency, such as a combination of S-band, Ku-band, and Ka-band, and clarify the operating parameters and performance requirements of each frequency band.

[0006] The second step involves designing a multi-layer substrate structure, with the number of substrate layers corresponding to the number of frequency bands. Low-frequency antenna elements are placed on the upper substrate, and high-frequency antenna elements on the lower substrate. The upper and lower antenna elements overlap or nest vertically, sharing the same horizontal physical aperture. For example, multiple high-frequency antenna elements can be accommodated within the coverage area of ​​one low-frequency antenna element, significantly improving space utilization. The low-frequency antennas utilize a microstrip patch structure, while the high-frequency antennas employ slot antennas or dielectric resonator antennas to reduce the obstruction between antennas of different frequency bands.

[0007] The third step involves deploying transceiver chips for the corresponding frequency bands on the back side of each substrate layer. These chips utilize a heterogeneous integration process, with each chip designed for a specific frequency band and manufactured using its own process to ensure optimal performance. The chips are electrically connected to the antenna elements of the corresponding layers via interlayer vias. These vias also serve to transmit RF signals and provide DC bias, simplifying the interconnect structure, shortening feeder lengths, and reducing signal transmission loss.

[0008] The fourth step involves setting a frequency selective surface or a metal ground isolation layer between adjacent substrate layers. The frequency selective surface is designed as a band-stop or band-pass type according to the frequency band isolation requirements, enabling precise switching between transmission and reflection for the target frequency band. For example, the isolation layer between the upper and middle layers reflects low-frequency bands and transmits high-frequency bands, while the isolation layer between the middle and lower layers reflects mid-frequency bands and transmits high-frequency bands, effectively suppressing mutual coupling interference between antennas of different frequency bands and ensuring that each frequency band operates independently.

[0009] The fifth step involves integrating the various substrate layers into a single unit using a lamination process to form a multi-band, common-aperture phased array module. The module thickness can be controlled to within 3mm, and the high-frequency antenna unit can be further embedded into the opening of the low-frequency antenna unit to optimize space utilization. The module can be prefabricated as an independent component, facilitating rapid integration into mobile terminals and improving assembly efficiency.

[0010] This method allows multiple frequency bands to share the same physical aperture, saving more than 60% of the area compared to the traditional independent layout. The performance of each frequency band antenna is close to that of an independent design. At the same time, by correspondingly laying out the chip and antenna on the back of the layer, the power supply path is shortened and the loss is reduced, perfectly balancing space utilization, communication performance and integration convenience. Attached Figure Description

[0011] Figure 1 is a schematic diagram of the stacked structure of a multi-band common-aperture phased array module. Figure 2 is a schematic diagram of the structure of the frequency selective surface. Figure 3 is a schematic diagram of the chip layout on the back of each substrate layer. Figure 4 is a schematic diagram of an optimized layout for embedding a low-frequency antenna into a high-frequency antenna. Figure 5 is a schematic diagram of the optimized layout of the multi-band common aperture module (formed by lamination). Detailed Implementation

[0012] The invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale. Furthermore, some well-known parts may not be shown in the drawings.

[0013] Many specific details of the invention, such as the structure, materials, dimensions, processing methods, and techniques of the devices, are described below to provide a clearer understanding of the invention. However, as those skilled in the art will understand, the invention may be implemented without following these specific details.

[0014] Figure 1 shows a schematic diagram of the stacked structure of a multi-band common-aperture phased array module.

[0015] As shown in Figure 1, the multi-band common aperture phased array module 100 of the present invention includes three substrates, which are, from top to bottom, an upper substrate 110, a middle substrate 120, and a lower substrate 130, respectively adapted to the S-band (2.5GHz), Ku-band (15GHz), and Ka-band (28GHz). The upper substrate 110 is made of Rogers 4350B material with a dielectric constant of 3.5 and a thickness of 1.5 mm. Square microstrip patch S-band antenna elements 111 with dimensions of 40 mm × 40 mm and a spacing of 60 mm are arranged on the surface. The middle substrate 120 is made of Rogers 3003 material with a dielectric constant of 3.0 and a thickness of 0.5 mm. Circular microstrip patch Ku-band antenna elements 121 with a diameter of 6 mm and a spacing of 10 mm are arranged on the surface. The lower substrate 130 is made of liquid crystal polymer (LCP) material with a dielectric constant of 3.0 and a thickness of 0.2 mm. Slotted Ka-band antenna elements 131 with a spacing of 5 mm are arranged on the surface. A first frequency selection surface 140 is provided between the upper and middle layers, and a second frequency selection surface 141 is provided between the middle and lower layers. The antenna elements of each layer overlap each other in the vertical direction and share a physical aperture of 60mm×60mm. The total thickness of the module is 2.2mm, which is less than 3mm.

[0016] Figure 2 shows a schematic diagram of the structure of the frequency selective surface.

[0017] As shown in Figure 2, the first frequency selective surface 140 is a band-stop structure using a periodic metal patch array. The metal patches 1401 are square, with a side length of 8 mm and a period of 10 mm, and are printed on a dielectric substrate 1402. The dielectric substrate 1402 has a thickness of 0.1 mm and a dielectric constant of 2.2. This frequency selective surface exhibits high reflectivity to the S-band (2.5 GHz), achieving isolation between S-band antennas and Ku or Ka-band antennas; it also exhibits high transmission characteristics to the Ku-band (15 GHz) and Ka-band (28 GHz) bands, without affecting high-frequency signal transmission. The second frequency selective surface 141 has a similar structure to the first frequency selective surface 140, with metal patches having a side length of 1.2 mm and a period of 1.5 mm. It exhibits high reflectivity to the Ku-band and high transmission to the Ka-band, achieving isolation between the Ku and Ka bands.

[0018] Figure 3 shows a schematic diagram of the chip layout on the back of each substrate layer.

[0019] As shown in Figure 3, an S-band transceiver chip 150, 10mm × 10mm in size, is mounted on the back of the upper substrate 110 and connected to the upper S-band antenna unit 111 via four interlayer vias 160. Four Ku-band transceiver chips 151, each 5mm × 5mm in size, are mounted on the back of the middle substrate 120 and connected to the middle Ku-band antenna unit 121 via interlayer vias 160. Sixteen Ka-band transceiver chips 152, each 2mm × 2mm in size, are mounted on the back of the lower substrate 130 and connected to the lower Ka-band antenna unit 131 via interlayer vias 160. Control and power signals from each layer of chips are aggregated to the interface pads 180 at the bottom of the module via a vertical interconnect channel 170, enabling interconnection with the mobile terminal motherboard.

[0020] Figure 4 shows a schematic diagram of an optimized layout for embedding a high-frequency antenna into a low-frequency antenna.

[0021] As shown in Figure 4, the S-band antenna element 111 is a square microstrip patch with a circular opening 112 at its center, with a diameter of 20mm. The Ku-band antenna element 121 is a circular microstrip patch embedded in the opening 112, sharing a central axis with the S-band antenna element 111. The Ka-band antenna element 131 is an annular slot structure arranged around the Ku-band antenna element 121. This embedded layout allows the three antenna elements to completely overlap in the vertical direction, reducing the physical aperture to 40mm×40mm, further saving space compared to traditional layouts. At the same time, the isolation effect of the frequency selective surface ensures that the performance of each frequency band is not affected.

[0022] The phased array module in this embodiment integrates one S-band antenna element, 16 Ku-band antenna elements, and 64 Ka-band antenna elements within a 60mm×60mm physical area through a common aperture design, for a total of 81 channels. The area utilization rate is more than 60% higher than that of traditional independent layouts. The isolation between each frequency band is greater than 35dB, with an S-band antenna gain of 10dBi, a Ku-band gain of 15dBi, and a Ka-band gain of 18dBi, approaching the performance of independent designs. The module is only 2.2mm thick and can be directly integrated between the back cover of the mobile phone and the motherboard, meeting the miniaturization requirements of mobile terminals.

[0023] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0024] In this invention, the embodiments do not exhaustively describe all details, nor are they intended to limit the invention to the specific embodiments described. Many variations can be made based on the above description. These embodiments have been selected and specifically described in this specification to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and make modifications based on it. This invention is limited only by the claims and their full scope and equivalents.

Claims

1. A phased array chip layout method supporting multiple frequency bands with the same aperture, characterized in that, Includes the following steps: S1: Determine the multiple operating frequency bands to be integrated and sort them from low to high frequency; S2: Design a multi-layer substrate, with low-frequency antenna units on the upper substrate and high-frequency antenna units on the lower substrate, with the upper and lower antennas vertically overlapping and sharing the same physical aperture; S3: Arrange the corresponding frequency band transceiver chips on the back of each substrate layer and connect them to the antenna units through interlayer vias; S4: Set frequency selective surfaces or metal ground isolation layers between layers to suppress frequency band mutual coupling; S5: Press the substrate layers together to form an integrated module, adapted to the multi-band satellite communication phased array system of mobile terminals.

2. The phased array chip layout method supporting multiple frequency bands with common aperture as described in claim 1, characterized in that, The operating frequency bands include at least two of the S-band, Ku-band, and Ka-band. The low-frequency antenna adopts a microstrip patch structure, and the high-frequency antenna adopts a slot antenna or a dielectric resonator antenna.

3. The phased array chip layout method supporting multiple frequency bands with common aperture as described in claim 1, characterized in that, The frequency selection surface is either band-stop or band-pass type, enabling transmission or reflection switching for the target frequency band, ensuring isolation between frequency bands, and suppressing mutual coupling interference.

4. The phased array chip layout method supporting multiple frequency bands with common aperture as described in claim 1, characterized in that, Each substrate layer uses radio frequency materials with different dielectric constants and thicknesses to adapt to the signal transmission requirements of the corresponding frequency bands. The interlayer vias simultaneously transmit radio frequency signals and DC bias.

5. The phased array chip layout method supporting multiple frequency bands with common aperture as described in claim 1, characterized in that, The transceiver chip adopts a heterogeneous integration process, with chips of different frequency bands adapted to the corresponding process and directly deployed on the back of the corresponding substrate, shortening the feeder length and reducing transmission loss.

6. The phased array chip layout method supporting multiple frequency bands with common aperture as described in claim 1, characterized in that, The high-frequency antenna unit can be embedded in the opening of the low-frequency antenna unit to further optimize space utilization; the integrated module is less than 3mm thick and can be prefabricated as an independent module for easy integration into mobile terminals.

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