Patent Publication Number: US-11031696-B2

Title: Antenna-in-package system and mobile terminal

Description:
TECHNICAL FIELD 
     The present disclosure relates to the field of wireless communication technologies, and in particular, to an antenna-in-package system and a mobile terminal. 
     BACKGROUND 
     With 5G being a focus of research and development in global industry, developing 5G technologies and formulating 5G standards have become the industry consensus. The ITU-RWP5D 22nd conference held in June 2015 by International Telecommunication Union (ITU) identified three main application scenarios for 5G: enhance mobile broadband, large-scale machine communication, and highly reliable low-latency communication. These three application scenarios respectively correspond to different key indicators, and in the enhance mobile broadband scenario, the user peak speed is 20 Gbps and the minimum user experience rate is 100 Mbps. Currently, 3GPP is working on standardization of 5G technology. The first 5G Non-Stand Alone (NSA) international standard was officially completed and frozen in December 2017, and the 5G Stand Alone standard was scheduled to be completed in June 2018. Research work on many key technologies and system architectures during the 3GPP conference was quickly focused, including millimeter wave technology. Characteristics of high carrier frequency and large bandwidth that are unique to the millimeter wave are the main means to achieve 5G ultra-high data transmission rates. 
     The rich bandwidth resources of the millimeter wave band provide a guarantee for high-speed transmission rates. However, due to the severe spatial loss of electromagnetic waves in this frequency band, wireless communication systems using the millimeter wave band need to adopt an architecture of a phased array. Phases of respective array elements are caused to distribute according to certain rule by a phase shifter, so that a high gain beam is formed and the beam is scanned over a certain spatial range through a change in phase shift. 
     With an antenna being an indispensable component in a radio frequency (RF) front-end system, it is an inevitable trend in future development of the RF front-end to systematically integrate and package the antenna with an RF front-end circuit while developing the RF circuit towards integration and miniaturization. The antenna-in-package (AiP) technology integrates, through package material and process, an antenna into a package carrying a chip, which fully balances antenna performance, cost and volume, and is widely favored by broad chip and package manufacturers. At present, companies including Qualcomm, Intel, IBM and the like have adopted the antenna-in-package technology. Undoubtedly, the AiP technology will also provide a good antenna solution for 5G millimeter wave mobile communication systems. 
     In the related art, since bands of 28 GHz and 39 GHz are far apart, the antenna-in-package cannot cover the two bands. Therefore, the band of 28 GHz and the band of 39 GHz belong two independent channels, which require a large area in space of a mobile phone. 
     Therefore, it is necessary to provide a new antenna-in-package system to solve the above problems. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Many aspects of exemplary embodiment can be better understood with reference to following drawings. Components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a perspective structural schematic diagram of a mobile terminal according to the present disclosure; 
         FIG. 2  is a schematic diagram showing a connection structure of an antenna-in-package and a main board shown in  FIG. 1 ; 
         FIG. 3  is a front view of an antenna-in-package system in  FIG. 1 ; 
         FIG. 4  illustrates a radiation pattern of a first antenna unit with a phase shift being 0° when an antenna-in-package system according to the present disclosure is in a band of 28 GHz; 
         FIG. 5  illustrates a radiation pattern of a second antenna unit with a phase shift being 0° when an antenna-in-package system according to the present disclosure is in a band of 39 GHz; 
         FIG. 6A  illustrates a coverage efficiency graph of an antenna-in-package system according to the present disclosure in a band of 28 GHz; and 
         FIG. 6B  illustrates a coverage efficiency graph of an antenna-in-package system according to the present disclosure in a band of 39 GHz. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The present disclosure will be further illustrated with reference to the accompanying drawings and the embodiments. 
     As shown in  FIGS. 1-3 , the present disclosure provides a mobile terminal  100 , and the mobile terminal  100  may be a mobile phone, an ipad, a POS machine, etc., which is not limited by the present disclosure. The mobile terminal  100  includes a screen  1 , a back cover  2  covering, connected to and fitting with the screen  1  to form a receiving space, a main board  3  interposed between the screen  1  and the back cover  2 , and an antenna-in-package system  4  connected to the main board  3 . 
     In order to more clearly express the content of the present disclosure, the mobile terminal  100  is positioned in a three-dimensional coordinate system in which a center point of an arrangement position of the antenna-in-package system  4  is taken as an origin. An X-axis of the three-dimensional coordinate system extends along a long axis direction of the mobile terminal  100 . A Y-axis of the three-dimensional coordinate system extends along a short axis direction of the mobile terminal  100 . A Z-axis of the three-dimensional coordinate system extends along a thickness direction of the mobile terminal  100 . A positive axis of the Y-axis is directed to a direction facing away from the mobile terminal  100 , and a positive axis of the Z-axis is directed to the back cover  2 . 
     The back cover  2  is a 3D glass back cover that can provide better protection, aesthetics, thermal diffusion, color, and user experience. The back cover  2  includes a bottom wall  21  arranged opposite to and spaced apart from the screen  1 , and a sidewall  22  being bent and extending from an outer periphery of the bottom wall  21  towards the screen  1 . The sidewall  22  is connected to the screen  1 , and the bottom wall  21  and the sidewall  22  are formed into one piece. 
     The main board  3  is received in the receiving space. 
     The antenna-in-package system  4  is provided adjacent to the sidewall  22  and parallel to the bottom wall  21 . The antenna-in-package system is configured to receive and transmit electromagnetic wave signals, thereby implementing a communication function of the mobile terminal  100 . The antenna-in-package system  4  can be connected to the main board  3  by adopting a Ball Grid array (BGA) technology. 
     The antenna-in-package system  4  includes a substrate  41  provided between the screen  1  and the back cover  2 , an integrated circuit chip  42  provided on a side of the substrate  41  close to the main board  3 , a metal antenna  43  provided on a side of the substrate  41  facing away from the main board  3 , and a circuit  44  provided in the substrate  41  and connecting the integrated circuit chip  42  with the metal antenna  43 . 
     The substrate  41  is configured to carry the metal antenna  43  and the circuit  44 . The substrate  41  may be integrally formed or layered. The integrated circuit chip  42  is fixedly connected to the substrate  41  by a bumping welding process. 
     The antenna-in-package system  4  is a dual-band antenna system. The metal antenna  43  includes a first antenna  431  and a second antenna  432  which are stacked. The first antenna  431  is provided on a side of the second antenna  432  facing away from the main board  3 . The first antenna  431  works in the band of 28 GHz. The second antenna  432  works in the band of 39 GHz. The isolation of the first antenna  431  and the second antenna  432  is better than −30 dB. 
     Further, the antenna-in-package system  4  is a millimeter wave phased array system, and the space occupied in the mobile phone is narrowed; and only one perspective needs to be scanned, which simplifies design difficulty, test difficulty, and beam management complexity. 
     The first antenna  431  is a one-dimensional linear array and includes a plurality of first antenna units  4311 , and the plurality of the first antenna units  4311  is arranged at interval along the X-axis direction. The second antenna  432  is a one-dimensional linear array and includes a plurality of second antenna units  4321 , and the plurality of the second antenna units  4321  is arranged at interval along the X-axis direction. Optionally, the first antenna  431  is a linear array of 1×4, that is, the first antenna  431  includes four first antenna units  4311 . The second antenna  432  is a linear array of 1×4, that is, the second antenna  432  includes four second antenna units  4321 . 
     Further, the first antenna  431  is selected from a group consisting of a dipole antenna, a monopole antenna, and a slot antenna. The second antenna  432  is selected from a group consisting of a square patch antenna, a ring patch antenna, a circular patch antenna, and a cross-shaped patch antenna. Optionally, the first antenna  431  is a dipole antenna, and the second antenna  432  is a square patch antenna. It is appreciated that, in other embodiments, the first antenna  431  and the second antenna  432  may also use antennas of other forms. 
     The beam of the first antenna  431  covers a space of Y&gt;0, and the beam of the second antenna  432  covers a space of Z&gt;0. That is, the first antenna  431  implements the beam scanning in the space of Y&gt;0, and the second antenna  432  implements the beam scanning in the space of Z&gt;0. 
     Compared to the antenna-in-package in the related art, the antenna-in-package system  4  in the present disclosure simultaneously packages the first antenna  431  and the second antenna  432  on the substrate  41  and arranges them in a stacking manner, such that the structure of the antenna system  3  becomes more compact so as to reduce the occupied space and, at the same time, the dual-band coverage of the antenna-in-package system  4  is achieved. Moreover, the antenna-in-package system  4  is formed by being laminated by a PCB process or an LTCC process, such that the size is reduced to 22×6 mm and the occupied area is greatly reduced compared to the dual-band antenna system in the related art. 
     Referring to  FIG. 4  to  FIG. 6B , in which: 
       FIG. 4  illustrates a radiation pattern of a first antenna unit with a phase shift being 0° when an antenna-in-package system according to the present disclosure is in a band of 28 GHz; 
       FIG. 5  illustrates a radiation pattern of a second antenna unit with a phase shift being 0° when an antenna-in-package system according to the present disclosure is in a band of 39 GHz; 
       FIG. 6A  illustrates a coverage efficiency graph of an antenna-in-package system according to the present disclosure in a band of 28 GHz; and 
       FIG. 6B  illustrates a coverage efficiency graph of an antenna-in-package system according to the present disclosure in a band of 39 GHz. 
     It can be seen from  FIG. 4  and  FIG. 5  in combination, the antenna-in-package system  4  provided by the present disclosure can achieve coverage in both of the Y-direction and the Z-direction. It can be seen from  FIG. 6A  and  FIG. 6B  in combination, in the band of 28 GHz, a gain threshold of the antenna-in-package system  4  is reduced by 7 dB for the case of 50% coverage efficiency, while the gain threshold is reduced by 12.98 dB for the case of 50% coverage efficiency in the 3GPP discussion; in the band of 39 GHz, the gain threshold of the antenna-in-package system  4  is reduced by 10 dB for the case of 50% coverage efficiency, while the gain threshold is reduced by 13.6-18.0 dB for the case of 50% coverage efficiency in the 3GPP discussion, showing that the AOG antenna system  4  of the present disclosure has the better coverage efficiency. 
     Compared to the related art, the antenna-in-package system  4  and the mobile terminal  100  provided by the present disclosure have following beneficial effects: the antenna-in-package system  4  simultaneously packages the first antenna  431  and the second antenna  432  on the substrate  41  to achieve the dual-band coverage of the antenna-in-package system  4 . Moreover, the antenna-in-package system  4  is formed by being laminated by a PCB process or an LTCC process, such that the size is reduced to 22×6 mm and the occupied area is greatly reduced compared to the dual-band antenna system in the related art. In addition, the first antenna  431  and the second antenna  432  are arranged in a stacking manner, which can further reduce the space occupied by the antenna-in-package system  4 ; the millimeter wave phased array antenna system adopts a linear array instead of a planar array, which occupies a narrower space in the mobile phone, and is only scanned in one perspective, thereby simplifying design difficulty, test difficulty, and beam management complexity. 
     What have been described above are only embodiments of the present disclosure, and it should be noted herein that those skilled in the art can make improvements without departing from the inventive concept of the present disclosure, but these are all within the scope of the present disclosure.