EP3843216A1

EP3843216A1 - Low-profile antenna-in-package

Info

Publication number: EP3843216A1
Application number: EP18936458.1A
Authority: EP
Inventors: Weixi ZHOU; Hongcheng YIN
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-10-12
Filing date: 2018-10-12
Publication date: 2021-06-30
Also published as: EP3843216A4; CN111989823B; CN111989823A; WO2020073329A1

Abstract

A low-profile antenna in package relates to the semiconductor field, and in particular, to the antenna in package field. The antenna in package includes a substrate, and a radio frequency processing chip electrically connected to the substrate. A feed path, radiation patches, and overlay arrays corresponding to the radiation patches are disposed in the substrate. The radio frequency processing chip feeds power to the radiation patches through the feed path, and resonates the overlay arrays. A reflection phase of each of the overlay arrays within an operating band is less than 90°, and there is a zero reflection phase region within the operating band. The overlay arrays may be metamaterial overlays. The antenna in package may be applied to a terminal device, especially a smartphone, to reduce a profile height of the antenna in package, so that the terminal device is more miniaturized.

Description

TECHNICAL FIELD

This application relates to the semiconductor field, and in particular, to an antenna in package.

BACKGROUND

As the 5G (5th-Generation) communication era begins, millimeter wave transmission has become an important choice for global operators. During the millimeter wave transmission, a millimeter-wave antenna plays an important role as a terminal transceiver. As a frequency of a communication signal increases, signal loss on a transmission line also increases sharply, to affect communication quality. Antenna in Package (AiP), can better resolve the problem of a large signal loss on the transmission line. In the AiP, an antenna (Antenna) is integrated with a chip and packed in a package structure. This reduces a transmission loss between the antenna and the chip, and effectively improves performance of the package structure.
A terminal device (especially a mobile phone device) has a complex internal structure and has a relatively strict requirement on a thickness of a millimeter-wave antenna in package. FIG. 1 is a schematic structural diagram of a millimeter-wave antenna in package 100, including an upper substrate 110 and a lower substrate 120 that are disposed oppositely, an upper radiation patch 130 (namely, an antenna) disposed on the lower surface of the upper substrate 110, and a lower radiation patch 140 disposed on the upper surface of the lower substrate 120. The upper substrate 110 and the lower substrate 120 are electrically connected by using solder balls 150. The upper radiation patch 130 and the lower radiation patch 140 are coupled and form dual resonance, to extend a bandwidth of the antenna. To meet a requirement of a relatively high bandwidth of the antenna, a spacing between the lower radiation patch 140 and the upper radiation patch 130 is relatively large. Consequently, it is difficult to meet a requirement of a terminal device (especially a mobile phone device) for a low profile of a millimeter-wave antenna in package. As a result, the terminal device has a relatively large size and becomes difficult to carry

SUMMARY

Embodiments of this application provide an antenna in package, to resolve a problem that an antenna in a terminal device, especially a mobile phone device, has a relatively high profile and occupies relatively large space.
According to a first aspect, an embodiment of this application provides an antenna in package, including a substrate, and a radio frequency processing chip disposed on a side of the substrate and electrically connected to the substrate. The substrate includes N radiation patches, N overlay arrays, and a feed path that are disposed in the substrate. The N overlay arrays are disposed on one side of the N radiation patches to respectively form N resonant cavities, and the one side faces away from the radio frequency processing chip. The radio frequency processing chip feeds power to the N radiation patches through the feed path, and resonates the N overlay arrays. A frequency of the overlay array when a reflection phase is 0° is within an operating band of the antenna in package. In other words, the overlay array has a zero reflection phase region within the operating band.
Because the frequency of the overlay array when the reflection phase is 0° is within the operating band, the overlay array has a lower reflection phase compared with an overlay array in the conventional technology, so that the radiation patch and the overlay array can still generate resonance after the resonant cavity of the antenna in package decreases in height. Therefore, reduction in the height of the resonant cavity by using the overlay array reduces the height of the entire antenna in package. This miniaturizes a profile of the antenna in package.
In a possible design, the overlay array is a metamaterial. The metamaterial is used as a material of the overlay array, and therefore, because having a special periodic structure, the metamaterial can provide, within the operating band, a reflection phase close to 0° for an incident electromagnetic wave.
In a possible design, the antenna in package further includes a dielectric layer configured to fill the resonant cavity. The dielectric layer is used to fill the resonant cavity, so that the overlay array obtains physical support, and a structure of the antenna in package is more stable.
In a possible design, the antenna in package further includes an antenna reference ground layer. The antenna reference ground layer is disposed on a side, of the radiation patch, facing the radio frequency processing chip, and is configured to provide a reference ground for the radiation patch. The antenna reference ground layer provides a reference ground for the radiation patch, so that the radiation patch can operate normally.
In a possible design, the antenna in package further includes a signal reference ground layer. The signal reference ground layer is disposed on a side, of the antenna reference ground layer, facing the radio frequency processing chip, and is configured to provide a reference ground for another signal such as a digital signal, an intermediate frequency signal, or a power supply signal. The signal reference ground layer provides a reference ground for another signal such as a digital signal, an intermediate frequency signal, or a power supply signal, so that the signal can operate normally.
In a possible design, the antenna in package further includes a signal layer. The signal layer is disposed on a side, of the signal reference ground layer, facing the radio frequency processing chip, and includes a routing of another signal such as a digital signal, an intermediate frequency signal, or a power supply signal. The signal layer is disposed in the antenna in package, so that the antenna in package can conduct and process another signal such as a digital signal, an intermediate frequency signal, or a power supply signal.
In a possible design, the overlay array includes a plurality of overlay patches arranged in an array, and a size of each overlay patch is less than a wavelength corresponding to any frequency within the operating band. Because the size of the overlay patch is less than the wavelength, the overlay array can change a phase of the incident electromagnetic wave.
In a possible design, the plurality of overlay patches are arranged in a Q × Q array, each overlay patch has a same size and shape, spacings between the overlay patches are the same, and Q is greater than 1. Even arrangement of the plurality of overlay patches simplifies a manufacturing process of the overlay patches.
In a possible design, a first frequency and a second frequency decrease as an area of each overlay patch increases. The first frequency is a corresponding frequency of the overlay array when the reflection phase is equal to -90°. The second frequency is a corresponding frequency of the overlay array when the reflection phase is equal to 90°. A reflection phase characteristic of the overlay array is adjusted by adjusting the area of the overlay patch, so that a zero reflection characteristic region provided by the overlay array can better cover the operating band.
In a possible design, the first frequency and the second frequency decrease as spacings between the overlay patches decrease. A reflection phase characteristic of the overlay array is adjusted by adjusting the spacings between the overlay patches, so that a zero reflection characteristic region provided by the overlay array can better cover the operating band.
In a possible design, a difference between the second frequency and the first frequency increases as a distance between the overlay array and the radiation patch (or a height of the formed resonant cavity) increases. The reflection phase characteristic of the overlay array is adjusted by adjusting the distance (or the height of the formed resonant cavity), so that the zero reflection characteristic region provided by the overlay array can better cover the operating band.
In a possible design, a resonance frequency generated by the overlay array decreases as an area of each overlay patch increases. The resonance frequency generated by the overlay array is adjusted by adjusting the area of the overlay patch, so as to facilitate adjustment in locations of two resonance points generated by the overlay array and the radiation patch, and obtain a better broadband characteristic within the operating band.
In a possible design, each overlay patch is a regular hexagon. Setting the overlay patch to a regular hexagon helps a feed path polarize a radiation patch corresponding to the feed path.
In a possible design, each overlay patch is a square. Setting the overlay patch to a square helps a feed path polarize a radiation patch corresponding to the feed path, and this is simpler in process and easy to implement.
In a possible design, the one or more overlay arrays are a plurality of overlay arrays arranged in an array. The plurality of overlay arrays arranged in an array may improve antenna performance, increase an antenna gain, and enhance an antenna beam sweeping capability.
In a possible design, the plurality of overlay arrays are arranged in an M × M array, spacings between the overlay arrays are the same, and M is greater than 1. Even arrangement of the plurality of overlay arrays simplifies a manufacturing process of the plurality of overlay arrays.
In a possible design, a center of one radiation patch and a center of one overlay array in the resonant assembly are aligned in a direction perpendicular to the substrate. Aligning the center of the radiation patch with the center of the overlay array enables the overlay array to generate better resonance.
In a possible design, the overlay array is a graphene array. Using graphene as a material for forming the overlay array may provide a reflection phase ranging from -90° to 90°.
In a possible design, the overlay array is a copper patch array. Using copper as a material for forming the overlay array may further reduce costs of manufacturing the antenna in package.
According to a second aspect, an embodiment of this application provides a radio frequency signal processing apparatus, including a printed circuit board, and an antenna in package that is disposed on a surface of the printed circuit board and that is electrically connected to the printed circuit board, where the antenna in package is the antenna in package in the first aspect and the possible designs of the first aspect.
Because the frequency of the overlay array when the reflection phase is 0° is within the operating band, the overlay array has a lower reflection phase compared with an overlay array in the conventional technology, so that the radiation patch and the overlay array can still generate resonance after the resonant cavity of the antenna in package decreases in height. Therefore, reduction in the height of the resonant cavity by using the overlay array reduces the height of the entire antenna in package. This miniaturizes the profile of the antenna in package.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of this application or in the conventional technology more clearly, the following briefly describes the accompanying drawings for describing the embodiments or the conventional technology.

FIG. 1 is a schematic structural diagram of a millimeter-wave antenna in package in the conventional technology;
FIG. 2 is a schematic diagram of an antenna in package according to an embodiment of this application;
FIG. 3 is a schematic diagram of a more specific antenna in package according to an embodiment of this application;
FIG. 4 is a top view of an overlay array according to an embodiment of this application;
FIG. 5 is a top view of another overlay array according to an embodiment of this application;
FIG. 6 is a reflection phase diagram of an overlay array according to an embodiment of this application;
FIG. 7 is a gain-frequency line graph of an antenna according to an embodiment of this application;
FIG. 8 is a top view of still another overlay array according to an embodiment of this application;
FIG. 9 shows a return loss curve of an antenna according to an embodiment of this application;
FIG. 10 is a schematic diagram of a sweeping characteristic of an antenna according to an embodiment of this application; and
FIG. 11 shows a terminal device according to an embodiment of this application.

Description of reference numerals:

Antenna in package 200; substrate 210; antenna reference ground layer 212; signal reference ground layer 214; signal layer 216; feed path 220; radio frequency signal routing 222; vertical polarization feed post 224; horizontal polarization feed post 226; metalized via 228; radiation patch 230; overlay array 240; overlay patch 242; radio frequency processing chip 250; solder ball 252; and a dielectric layer 260.

DESCRIPTION OF EMBODIMENTS

The following clearly and completely describes the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. It is clearly that the described embodiments are merely some but not all of the embodiments of this application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the protection scope of this application.
It should be noted that, in the embodiments of this application, "a plurality" refers to two or more, for example, may be two, three, or four. In addition, it should be understood that, in the descriptions of this application, terms such as "first" and "second" are merely used for distinguishing and description purposes, and cannot be understood as indicating or implying relative importance, or as indicating or implying a sequence. In addition, in the descriptions of this application, terms such as "upper" and "lower" are only used to distinguish relative orientations, and cannot be understood as a limitation on orientations. That A includes at least one of B or C means that A includes B, C, or B + C.
FIG. 2 is a schematic sectional view of an antenna in package 200 according to this application. The antenna in package 200 may be configured to process and transmit an electromagnetic wave signal, for example, a millimeter wave signal. The antenna in package 200 includes a substrate 210 and a radio frequency processing chip 250 disposed on a lower surface side of the substrate 210. The radio frequency processing chip 250 is electrically connected to the substrate 210, for example, by using a plurality of solder balls 252. The radio frequency processing chip 250 may be configured to perform frequency synthesis and power amplification on an electromagnetic wave signal. For example, the radio frequency processing chip 250 may include at least one of a power amplifier (Power Amplifier, AP), an antenna switch (Switch), a filter (Filter), a duplexer (Duplexer), or a low noise amplifier (Low Noise Amplifier, LNA). The substrate 210 includes a feed path 220, N radiation patches 230, and N overlay arrays 240 that are disposed in the substrate 210 (N ≥ 1 and N is an integer). The overlay array 240 is disposed on an upper surface side of the radiation patch 230, to be specific, a side, of the radiation patch 230, facing away from the radio frequency processing chip 250. The N overlay arrays 240 and the N radiation patches 230 corresponding to the N overlay arrays 240 form N resonant cavities. In the resonant cavity, a center of the overlay array 240 and a center of the radiation patch 230 are aligned in a vertical direction. A reflection phase of the overlay array 240 is greater than or equal to -90° and less than or equal to 90° within an operating band of the antenna, and the reflection phase within the operating band may reach 0°, to be specific, a reflection phase of at least one frequency within the operating band may reach 0°. Ideally, the reflection phase of the overlay array 240 may be close to 0° within the operating band. The radio frequency processing chip 250 feeds power to the radiation patch 230 through the feed path 220, to excite radiant energy. In this application, the operating band is an operating band of the antenna in the antenna in package 200, to be specific, a frequency of an electromagnetic wave transmitted or received by the antenna during normal operation, for example, from 24 GHz to 29 GHz. The antenna may include the radiation patch 230, the overlay array 240, and another signal layer such as a ground layer, an intermediate frequency signal layer, or a low frequency signal layer. The antenna in package 200 shown in FIG. 2 is described by using one radiation patch 230 and one overlay array 240 as an example. The antenna in package 200 according to the embodiments of this application may include at least N radiation patches 230 and N overlay arrays 240.
A reflection phase (reflection phase) is a parameter for a reflection plane and is defined as a phase change of the reflection plane to an incident wave. For example, a perfect electric conductor (Perfect Electric Conductor, PEC) has a reflection phase of 180°. When a phase of an incident wave is Φ, a phase of the reflected wave is Φ + 180°. A perfect magnetic conductor (Perfect Magnetic Conductor, PMC) has a reflection phase of 0°. When a phase of an incident wave is Φ, a phase of the reflected wave is also Φ.
The resonant cavity in the antenna in package 200 meets the following formula: $- 4 π f d / c + Δ Φ_{1} + Δ Φ_{2} = m 2 π$
In this formula, f is a frequency of an electromagnetic wave received or transmitted by the antenna in package 200, d is a height of the resonant cavity, to be specific, a distance between the radiation patch 230 and the overlay array 240 in a normal direction of the radio frequency processing chip 250, c is a speed of light, and ΔΦ ₁ is an absolute value of a reflection phase of the overlay array 240, ΔΦ ₂ is an absolute value of a reflection phase of the radiation patch 230, and m is any integer. When the reflection phase ΔΦ ₂ of the radiation patch 230 is 90° and remains unchanged, the reflection phase ΔΦ ₁ of the overlay array 240 within the operating band may change from 90° in the conventional technology to less than 90° within the operating band, and a reflection phase of at least one frequency within the operating band reaches 0°. In formula (1), if m remains unchanged, ΔΦ ₁ decreases and the height d of the resonant cavity decreases accordingly and simultaneously. Therefore, using the overlay array 240 whose reflection phase can reach 0° within the operating band can reduce the height d of the resonant cavity. This reduces a profile of the antenna in package 200, so that the antenna in package 200 can meet a requirement of a terminal device (especially a mobile phone) for a low-profile antenna in package.
For example, the reflection phase ΔΦ ₁ of the overlay array 240 used in the conventional technology within the operating band is 90°, and the reflection phase ΔΦ ₂ of the radiation patch 230 is also 90°. The foregoing parameters are substituted into formula (1) to obtain: $- 4 π f d_{1} / c + π = m 2 π$
When m = 0, a height d₁ of the resonant cavity may be a minimum positive value, to be specific, d₁ = c/(4f) = 1/4λ. However, in the antenna in package 200 according to this embodiment of this application, the reflection phase ΔΦ ₁ of the overlay array 240 within the operating band may be close to 0° in an ideal case, and the foregoing data may be substituted into formula (1) to obtain: $- 4 π f d_{2} / c = m 2 π - 1 / 2 π$
When m = 0, a height d₂ of the resonant cavity may be a minimum positive value, to be specific, d₂ = 1/8λ. Therefore, the height d of the resonant cavity is reduced from 1/4λ to 1/8λ, reducing the profile of the antenna in package 200.
FIG. 3 is a schematic sectional view of a more specific antenna in package 300. The antenna in package 300 further includes an antenna reference ground layer 212, a signal reference ground layer 214, and a signal layer 216 that are disposed in the substrate 210, and a dielectric layer 260 that is configured to fill the resonant cavity and disposed in the substrate 210. The dielectric layer 260 is disposed between the radiation patch 230 and the overlay array patch 240, to support the overlay array patch 240, and fill the resonant cavity formed between the radiation patch 230 and the overlay array patch 240. In an implementation, a material of the dielectric layer 260 may be the same as a material of the substrate 210. In another implementation, the dielectric layer 260 may use a microwave dielectric material, for example, one of the following materials: BaO-TiO₂, Al₂O₃ perovskite ceramic, polytetrafluoroethylene, quartz, or beryllium oxide.
The antenna reference ground layer 212 is disposed below the radiation patch 230, to be specific, a side, of the radiation patch 230, facing the radio frequency processing chip 250, and is configured to provide a reference ground of the radiation patch 230. The signal reference ground layer 214 is disposed below the antenna reference ground layer 212, to be specific, a side, of the antenna reference ground layer 212, facing the radio frequency processing chip 250, and is configured to provide a reference ground for a digital signal, an intermediate frequency signal, a power supply signal, and another signal. The signal layer 216 is disposed below the signal reference ground layer 214, to be specific, a side, of the signal reference ground layer 212, facing the radio frequency processing chip 250. The signal layer 216 includes a routing of at least one of a digital signal, an intermediate frequency signal, and a power supply signal. It should be noted that the substrate 210 may include one or more antenna reference ground layers 212, one or more signal reference ground layers 214, or one or more signal layers 216. A specific quantity and an arrangement sequence of the antenna reference ground layers 212, the signal reference ground layers 214, and the signal layers 216 are not limited in this application.
In this embodiment of this application, a dual-polarization antenna is used as an example to describe an operating principle of the antenna in package 300. Alternatively, the antenna in package 300 may be a single-polarization antenna. It should be noted that a polarization manner of the antenna in package 300 is not limited in this application. The feed path 220 in the antenna in package 300 includes a radio frequency signal routing 222 and a feed post. The radio frequency signal routing 222 provides an appropriate matching circuit for the radiation patch 230, so as to extend an antenna bandwidth. In addition, a length of the radio frequency routing is properly controlled, so that a phase of each radio frequency channel from the radio frequency processing chip 250 to the radiation patch 230 reaches a preset value. The feed post includes a vertical polarization feed post 224 and a horizontal polarization feed post 226, so as to excite radiant energy of the radiation patch 230 in a horizontal polarization direction and in a vertical polarization direction. This achieves a dual polarization purpose. The antenna in package 300 further includes one or more metalized vias 228. The vertical polarization feed post 224 and the horizontal polarization feed post 226 are disposed in the metalized vias 228. The vertical polarization feed post 224 and the horizontal polarization feed post 226 excite the radiation patch 230 and generate a first resonance frequency. The first resonance frequency excites the overlay radiation array 240, and enables the overlay radiation array 240 to generate a second resonance frequency. A bandwidth of the antenna in package 300 during operation is determined by using the first resonance frequency and the second resonance frequency. Specifically, a frequency of an electromagnetic wave transmitted or received by the antenna in package 300 is between the first resonance frequency and the second resonance frequency (including the first resonance frequency and the second resonance frequency).
A material of the overlay array 240 may be a metamaterial (Metamaterial), a reflection phase of the metamaterial within an operating band is greater than or equal to -90° and less than or equal to 90°, and a frequency of the metamaterial when the reflection phase is 0° is within the operating band. The metamaterial is an artificial material with a periodic arrangement structure, and by using a special and precise geometrical structure and size, realizes characteristics that ordinary materials do not have. A size of a microstructure in the metamaterial is less than a wavelength of an electromagnetic wave that the metamaterial acts on, to exert an influence on the electromagnetic wave, for example, providing a reflection phase close to 0° for the electromagnetic wave. The metamaterial forming the overlay array 240 may be graphene (Graphene), or may be metal, for example, copper or silver. For example, in an implementation, the overlay array 240 is a copper patch array.
The overlay patch array 240 includes a plurality of overlay patches arranged in an array. The array arrangement may be a square array arrangement, for example, a Q × Q array arrangement (Q > 1), or may be a rectangular array arrangement, for example, a P × Q array arrangement (P ≠ Q and P > 1), or may be a single-column array arrangement, for example, a Q × 1 array arrangement (Q > 1), or may be a trapezoidal array arrangement, or may be an array arrangement of another shape. Details are not described herein.
FIG. 4 is a top view of the overlay array 240, and a plurality of overlay patches 242 arranged in a Q × Q array are used as an example for description. The overlay array 240 includes a plurality of overlay patches 242 arranged in a Q × Q array. In FIG. 4, Q = 4, and each overlay patch 242 is a square. However, this application sets no limitation on Q or a specific shape of the overlay patch 242, provided that Q > 1. A size of each overlay patch 242 is less than a wavelength λ of an electromagnetic wave transmitted or received by the antenna of the antenna in package 300, in other words, less than a wavelength corresponding to any frequency within the operating band of the antenna. Each overlay patch 242 is of the same size and shape, and spacings D₁ between two adjacent overlay patches 242 are the same, to provide a reflection phase closer to 0° within the operating band. A shape of the overlay patch 242 may be a square with a side length of L₁. In this case, spacings between edges of every two overlay patches 242 are D₁. When the overlay patch 242 is a square, the spacing D₁ is a vertical distance between two nearest edges of two adjacent overlay patches 242 in a row or column of overlay patches 242. The center of the radiation patch 230 (represented by a dashed box) and the center of the overlay array 240 are aligned in a vertical direction (or in a normal direction of the radio frequency processing chip 250), so that the radiation patch 230 and the overlay array 240 obtain a more symmetric pattern characteristic. The vertical polarization feed post 224 and the horizontal polarization feed post 226 form two feed points with the radiation patch 230. The two feed points are located on two orthogonal edges of the radiation patch 230. To be specific, the two feed points are located on two straight lines that each are perpendicular to the edge of the radiation patch 230 and passing through the center of the radiation patch 230, and have equal distances from the center of the radiation patch 230, so as to better perform vertical polarization and horizontal polarization on an electromagnetic wave signal.
FIG. 5 is a top view of another overlay array 240. FIG. 5 is different from FIG. 4 in that an overlay patch 242 in the overlay array 240 in FIG. 5 is a regular hexagon, a side length of each overlay patch 242 is L₁, and a spacing is D₁. When the overlay patch 242 is a regular hexagon, the spacing D₁ is a distance between two nearest points on edges of two adjacent overlay patches 242 in a row or column of overlay patches 242. Similarly, the center of a radiation patch 230 (represented by a dashed box) and the center of the overlay array 240 are aligned in a vertical direction (or in a normal direction of the radio frequency processing chip 250), so that the overlay array 240 better generates resonance. A feed point between a vertical polarization feed post 224 and the radiation patch 230 and a feed point between a horizontal polarization feed post 226 and the radiation patch 230 are located on two orthogonal edges of the radiation patch 230, and have equal distances from the center of the radiation patch 230, so as to better perform vertical polarization and horizontal polarization on an electromagnetic wave signal.
FIG. 6 is a possible reflection phase diagram of the overlay array 240. A horizontal axis Freq is a frequency f of an electromagnetic wave, and a vertical axis ΔΦ ₁ is a reflection phase ΔΦ ₁ of the overlay array 240. A reflection phase ΔΦ ₁ of the overlay array 240 at a frequency f of 23.5 GHz is 90°, a point P1 in FIG. 6; a reflection phase ΔΦ ₁ at a frequency f of 32 GHz is -90°, a point P2; and a reflection phase ΔΦ ₁ at a frequency f of 27.5 GHz is 0°, a point P3. An area near the point P3 is generally referred to as a zero reflection phase region. A frequency range between the point P1 and the point P3 is a zero reflection phase characteristic region 610 of the overlay array 240. An antenna whose operating band is from 24 GHz to 29 GHz is used as an example for description. When the antenna during normal operation is within the operating band, the zero reflection phase characteristic region 610 can always cover the operating band, so that even if the height d of the resonant cavity decreases, the overlay array 240 can still generate resonance and operate normally.
When the operating band required by the antenna changes, the reflection phase of the overlay array 240 within the operating band may be changed by adjusting the side length L₁ (or an area) and the spacing D₁ of the overlay patch 242, so as to change a location of the zero reflection phase characteristic region (a region 610), so that the region 610 can cover the operation. For example, increasing the side length L₁ (or the area) of the overlay patch 242, or reducing the spacing D₁ between the overlay patches 242, or increasing the side length L₁ (or the area) and simultaneously reducing the spacing D₁, may enable the region 610 to translate leftward in FIG. 6 to cover a region 620, so that the zero reflection phase characteristic region can always cover the operating band of the antenna in package 300. Increasing the distance between the overlay patch 242 and the radiation patch 230 (or increasing the height d of the resonant cavity) widens the region 610, to be specific, enlarges a frequency range corresponding to the zero reflection phase characteristic region, so that the zero reflection phase characteristic region better covers the operating band of the antenna in package 300.
FIG. 7 shows a curve of an antenna gain changing with a frequency. A horizontal axis Freq is a frequency of an electromagnetic wave, and a vertical axis dB is an antenna gain. It should be noted that the antenna gain in this application is a gain of the antenna in package 300. The antenna gain is approximately 3.1 dBi at a frequency f of 24 GHz, a point P1 in FIG. 7, and approximately 4.7 dBi at a frequency f of 29 GHz, a point P2 in FIG. 7. It can be learned from the gain curve in FIG. 7 that, in a frequency band ranging from 24 GHz to 29 GHz, the antenna gain is greater than 3 dBi, and has a relatively good gain characteristic. Increasing the spacing L between every two overlay arrays 240 may increase the antenna gain.
The antenna in package 300 may include a plurality of overlay arrays 240, and the plurality of overlay arrays 240 are arranged in an array to further improve an antenna gain. The array arrangement may be a square array arrangement, for example, an M × M array arrangement, where M × M = N; or may be a rectangular array arrangement, for example, an M × L array arrangement (M ≠ L), where M × L = 0; or may be a trapezoidal array arrangement; or may be an array arrangement of another shape. Details are not described herein.
A plurality of overlay arrays 240 arranged in an M × M array are used as an example for description, spacings L₂ between two adjacent overlay arrays 240 are equal, and M > 1. In this case, the spacing L₂ is a vertical distance between two nearest edges of two adjacent overlay arrays 240 in a row or column of overlay arrays 240. FIG. 8 is a top view of an antenna in package 300. The antenna in package 300 includes 3 × 3 arrayed overlay arrays 240 and 3 × 3 arrayed radiation patches 230. Each overlay array and one radiation patch 230 act as a resonant assembly to form a resonant cavity. In each resonant assembly, the center of the radiation patch 230 and the center of the overlay array 240 are aligned in a vertical direction (or in a normal direction of the radio frequency processing chip 250), so that the radiation patch 230 and the overlay array 240 obtain a more symmetric pattern characteristic. A digital phase shifter in the radio frequency processing chip 250 may set an amplitude-phase ratio for each radiation patch 230, so as to achieve a beam sweeping feature. The arrayed overlay array 240 and the arrayed radiation patch 230 may increase the antenna gain. Further, an antenna gain and a beam sweeping capability may be changed by adjusting spacings L₂ between every two overlay arrays 240. Specifically, increasing the spacing L₂ may increase the antenna gain, and decreasing the spacing L₂ may increase a beam sweeping angle of the radiation patch 230. By adjusting the spacing L₂ properly, the gain and the beam sweeping angle can be within an optimal range.
FIG. 9 shows a return loss (Return Loss) curve of an antenna obtained through simulation. A horizontal axis Freq is a frequency of an electromagnetic wave, and a vertical axis dB is a return loss of the antenna. The return loss curve corresponds to a case in which a plurality of overlay arrays 240 are arranged in an array. A region 910 is an actual operating band of the antenna, and two concave points P1 and P2 in the return loss curve are two resonance points generated by the radiation patch 230 and the overlay array 240. It should be noted that a frequency of the resonance point generated by the radiation patch 230 may be less than a frequency of the resonance point generated by the overlay array 240. In this case, P1 is the resonance point generated by the radiation patch 230, and P2 is the resonance point generated by the overlay array 240. Alternatively, a frequency of the resonance point generated by the radiation patch 230 may be greater than a frequency of the resonance point generated by the overlay array 240. In this case, P1 is the resonance point generated by the overlay array 240, and P2 is the resonance point generated by the radiation patch 230. It can be learned from the return loss curve in FIG. 9 that, when the return loss of the antenna is less than -10 dB, a frequency range covered by the antenna is approximately from 23.13 GHz to 30.79 GHz, and the frequency range includes all frequency bands of the 24 GHz to 28 GHz millimeter wave in the globe. Thus, the two resonance points generated by the overlay array 240 and the radiation patch 230 enable the antenna to obtain a wider bandwidth under the condition of a relatively low return loss.
A resonance frequency generated by the overlay array 240 may be changed by adjusting the side length L₁ (or the area) of the overlay patch 242. Specifically, increasing the side length L₁ (or the area) may reduce the resonance frequency generated by the overlay array 240, or reducing the side length L₁ (or the area) may increase the resonance frequency generated by the overlay array 240. For example, a point P1 in FIG. 9 is a first resonance point generated by the overlay array 240, and a point P2 is a second resonance point generated by the radiation patch 230. When a frequency of the first resonance point is relatively low, a loss within the operating band range may be greater than - 10 dB, to affect a capability of transmitting or receive an electromagnetic wave by the antenna in package 300. Therefore, the frequency of the first resonance point is increased by properly reducing the side length L₁ (or the area), so that a return loss characteristic (parameter S11) meets a requirement and a relatively good broadband characteristic is obtained within the operating band.
FIG. 10 is a schematic diagram of a sweeping characteristic of an antenna. A horizontal axis Theta is a sweeping angle during beam sweeping, and a vertical axis dB is an antenna gain. Each curve corresponds to a gain of an electromagnetic wave in the beam sweeping result. For example, a curve 1010 in FIG. 10 shows an antenna gain when the sweeping angle is -20°, and the electromagnetic wave has a maximum gain of 10 dB when the sweeping angle is -20°. A larger angle that can be swept by the radiation patch 230 indicates a stronger beam sweeping capability. Reducing the spacing L₂ may increase the beam sweeping angle of the radiation patch 230, to be specific, increase an angle of a beam that can be swept. This enhances a beam sweeping capability.
FIG. 11 shows a terminal device 1100 configured to transmit, receive, and process a radio frequency signal. The terminal device 1100 may be a mobile phone, a tablet, a portable computer, a palmtop computer, a sports band, or the like. The terminal device 1100 includes a bus interface 1110, a processor 1120, a memory 1130, and a radio frequency circuit 1140. The processor 1120 and the memory 1130 are communicatively coupled, and a high-speed data transmission connection exists. The high-speed data transmission connection may be implemented by separately communicatively connecting bus interfaces 1110 of the processor 1120 and the memory 1130. The bus interface 1110 may be a PCIe (Peripheral Component Interconnect express, peripheral component interconnect express) interface, an AGP (Accelerated Graphical Port, accelerate graphical port), or another type of bus interface. The processor 1120 may be a central processing unit (Central Processing Unit, CPU), and is configured to run a software program and/or an instruction stored in the memory 1130, to execute various functions of the terminal device 1100. Alternatively, the processor 1120 may be an application processor (Application Processor, AP) and/or an image signal processor (Image Signal Processor, ISP). The memory 1130 may include a volatile memory, for example, a random access memory (Random Access Memory, RAM), or may include a non-volatile memory such as a flash memory (flash memory), a hard disk, or a solid-state drive (Solid-State Drive, SSD), or may be a combination of the foregoing types of memories. In a possible implementation, the bus interface 1110, the processor 1120, and the memory 1130 may be disposed on one PCB (Printed Circuit Board, printed circuit board), and data is transmitted and processed by using a conductive path disposed on the PCB. Alternatively, the bus interface 1110, the processor 1120, and the memory 1130 may be disposed on a plurality of PCBs, and data is transmitted through a general I/O interface or another communications interface. In another possible implementation, the processor 1120 and the memory 1130 are integrated and packed in one package apparatus.
The radio frequency circuit 1140 includes the antenna in package 300 according to the embodiments of this application. In an implementation, the antenna in package 300 may be disposed on the PCB together with the bus interface 1110, the processor 1120, and the memory 1130, and is electrically connected to the PCB by using a plurality of solder balls. The antenna in package 300 is configured to receive an electromagnetic wave signal, convert the electromagnetic wave signal into a radio frequency signal to be processed, and transmit the processed signal to the processor 1120, the memory 1130, or another circuit. A signal in the processor 1120, the memory 1130, or another circuit may also be input to the antenna in package 300, processed, converted into an electromagnetic wave signal, and then transmitted by using the antenna in package. In another implementation, the radio frequency circuit 1140 may be integrated with at least one of the bus interface 1110, the processor 1120, or the memory 1130 and packed into one package apparatus.
In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the described apparatus embodiment is merely an example. For example, the circuit division is merely logical function division and may be other division during actual implementation. For example, a plurality of circuits or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces. The indirect couplings or communication connections between the apparatuses or circuits may be implemented in an electronic form, a mechanical form, or another form.
The foregoing descriptions are merely specific implementations of this application, but are not intended to limit the protection scope of this application. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

An antenna in package, wherein the antenna in package comprises a substrate and a radio frequency processing chip;
the radio frequency processing chip is disposed on a side of the substrate, and is electrically connected to the substrate; and
the substrate comprises N radiation patches, N overlay arrays, and a feed path that are disposed in the substrate; the N overlay arrays are disposed on one side of the N radiation patches to respectively form N resonant cavities, and the one side faces away from the radio frequency processing chip, and a frequency of each of the N overlay arrays when a reflection phase is 0° is within an operating band, wherein the operating band is a frequency range of an electromagnetic wave transmitted or received by the antenna in package during normal operation; and the radio frequency processing chip is configured to feed power to the N radiation patches through the feed path, wherein N is an integer greater than or equal to 1.
The antenna in package according to claim 1, wherein the overlay array is a metamaterial.
The antenna in package according to claim 1 or 2, wherein the antenna in package further comprises a dielectric layer, and the dielectric layer is configured to fill the N resonant cavities.
The antenna in package according to any one of claims 1 to 3, wherein each of the N overlay arrays comprises a plurality of overlay patches arranged in an array, and a size of each of the plurality of overlay patches is less than a wavelength corresponding to any frequency within the operating band.
The antenna in package according to claim 4, wherein the plurality of overlay patches are arranged in a Q × Q array, each overlay patch has a same size and shape, any two adjacent overlay patches have a same spacing, and Q is greater than 1.
The antenna in package according to claim 4 or 5, wherein each overlay patch is a square.
The antenna in package according to any one of claims 1 to 6, wherein the N overlay arrays are a plurality of overlay arrays, and the plurality of overlay arrays are arranged in an array.
The antenna in package according to claim 7, wherein the plurality of overlay arrays are arranged in an M × M array, any two adjacent overlay arrays of the plurality of overlay arrays have a same spacing, and M is greater than 1.
The antenna in package according to any one of claims 1 to 8, wherein the overlay array is a copper patch array.
A terminal device, wherein the terminal device comprises a printed circuit board PCB and the antenna in package according to any one of claims 1 to 9, and the antenna in package is disposed on a surface of the PCB and is electrically connected to the PCB.