Antenna-in-package system and mobile terminal

The present disclosure provides an antenna-in-package system and a mobile terminal. The mobile terminal includes a main board, wherein the antenna-in-package system includes a substrate, a metal antenna provided on a side of the substrate facing away from the main board, an integrated circuit chip provided on a side of the substrate facing towards the main board, a feeding network provided in the substrate and spaced apart from the metal antenna, and a circuit connecting the feeding network with the integrated circuit chip. The circuit is electrically connected to the main board. The feeding network is provided with a slit at a position corresponding to the metal antenna. The metal antenna is fed with power by coupling with the feeding network via the slit.

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 the focus of research and development in the global industry, developing 5G technologies and formulating 5G standards have become the industry consensus. The ITU-RWP5D 22nd meeting 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-StandAlone (NSA) international standard was officially completed and frozen in December 2017, and the 5G StandAlone 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 the millimeter wave technology. The high carrier frequency and large bandwidth characteristics 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. The phases of respective array elements are caused to distribute according to certain regularity 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 the future development of the RF front-end to system-integrate and package the antenna with a RF front-end circuit while developing the RF circuit towards the direction of integration and miniaturization. The antenna-in-package (AiP) technology integrates, through package material and process, the antenna into a package carrying a chip, which fully balances the 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 antenna package technology, it is difficult to achieve a bandwidth above 10% in a fixed stacked structure in a limited space of the antenna-in-package system.

Therefore, it is indeed necessary to provide a new antenna-in-package system and a new mobile terminal to solve the above problems.

DESCRIPTION OF EMBODIMENTS

The present disclosure will be further illustrated with reference to the accompanying drawings and the embodiments.

As shown inFIGS. 1-3, the present disclosure provides a mobile terminal100. The mobile terminal100may be a mobile phone, an ipad, a POS machine, etc., which is not limited by the present disclosure. The mobile terminal100includes a frame1, a 3D glass back cover2covering and connected to the frame1and enclosing a receiving space with the frame1, a main board3received in the receiving space and spaced apart from the 3D glass back cover2, and an antenna-in-package system4electrically connected to the main board3.

The 3D glass back cover2can cover and be connected to the frame1by an adhesive, or the frame1and the 3D glass back cover2may be respectively provided with a corresponding buckle structure, such that the 3D glass back cover2can be fixedly connected to the frame1by a buckling manner. Alternatively, the frame1and the 3D glass back cover may be formed into one piece. The 3D glass back cover2can provide better protection, aesthetics, thermal diffusion, color, and user experience.

The antenna-in-package system4can receive and transmit electromagnetic wave signals, thereby achieving the communication function of the mobile terminal100. Specifically, the antenna-in-package system4can be connected to the main board3through BGA package technology.

The antenna-in-package system4is a millimeter wave phased array. Specifically, the antenna-in-package system4includes a substrate41, a metal antenna42provided on a side of the substrate41facing away from the main board3, a feeding network43provided in the substrate41and spaced apart from the metal antenna42, an integrated circuit chip44provided on a side of the substrate41facing towards the main board3, and a circuit45connecting the feeding network44with the integrated circuit chip44.

The substrate41is used to carry other components of the antenna-in-package system4. The substrate41may be formed as a whole or may be arranged by layers.

The metal antenna42may be selected from one of a square patch antenna, a ring patch antenna, a circular patch antenna, and a cross-shaped patch antenna. As an example, the metal antenna42may be a square patch antenna. Without doubt, in other embodiments, the metal antenna42may also use an antenna of other forms.

Further, the metal antenna42is a one-dimensional linear array, occupies a narrow space in the mobile phone, and is scanned only in one perspective, which simplifies design difficulty, test difficulty, and beam management complexity. As an example, the metal antenna42may be a linear array of 1×4, i.e., the metal antenna42includes four metal antenna units421.

The feeding network43is a strip wire having impedance that is easy to control and having better shielding, which can effectively reduce the loss of electromagnetic energy and improve the antenna efficiency. The feeding network43includes a first metal layer431close to the metal antenna42, a second metal layer432arranged opposite to and spaced apart from the first metal layer431, and a stripe wire layer433sandwiched between the first metal layer431and the second metal layer432.

The first metal layer431is provided with a slit40at a position corresponding to the metal antenna42, and the feeding network43feeds power by coupling via the slit40.

The number of the slits40matches the number of the metal antenna units421and each of the metal antenna units421is fed with power by coupling via the slit40. Specifically, electromagnetic energy is coupled to the metal antenna unit421through the slit40. In the present embodiment, the number of the slits40is four, and each of the slits40is provided corresponding to one of the metal antenna units421.

Referring toFIG. 4, in the embodiment, the slit40is in an I-shape. The slit40includes a first portion410, a second portion420arranged in parallel with and spaced apart from the first portion410, and a third portion430connecting the first portion410with the second portion420. The first portion410, the second portion420, and the third portion430are all linear slits. Two ends of the third portion430are connected to centers of the first portion410and the second portion420, respectively. The strip wire layer433includes an elongated transmission line4331. An orthographic projection of the third portion430on the strip wire layer433intersects perpendicularly with the transmission line4331. Orthographic projections of the first portion410and the second portion420on the strip wire layer433are located on two sides of the transmission line4331and symmetrical about the transmission line4331.

In other embodiments, the shape of the slit40may also be square, annular, circular or triangular, which is not limited in the present disclosure.

Further, the orthographic projection of the slit40towards the metal antenna unit421completely falls within the range of the metal antenna unit421.

The integrated circuit chip44is fixedly connected with the substrate41by the flip-chip bonding process.

Referring toFIG. 5AtoFIG. 6,FIG. 5Aillustrates a radiation pattern with a phase shift of each metal antenna unit being 45° in the antenna-in-package system provided by the present disclosure,FIG. 5Billustrates a radiation pattern with a phase shift of each metal antenna unit being 0° in the antenna-in-package system provided by the present disclosure,FIG. 5Cillustrates a radiation pattern with a phase shift of each metal antenna unit being −45° in the antenna-in-package system provided by the present disclosure, andFIG. 6illustrates a coverage efficiency graph of an antenna-in-package system provided by the present disclosure. As can be seen fromFIG. 6, in the case where the coverage efficiency is 50%, the gain threshold of the antenna-in-package system4is reduced by 12.4 dB, while in the 3GPP discussion, the gain threshold is reduced by 12.98 dB for the case of 50% coverage efficiency, showing that the antenna-in-package system4of the present disclosure has the better coverage efficiency.

Compared with the packaged antenna in the related art, the antenna-in-package system4in the present embodiment is formed by stacking using a PCB process or an LTCC process, and achieves a larger antenna impedance bandwidth of at the same thickness by feeding the metal antenna42with power by coupling with the feeding network43. Taking an impedance bandwidth of n257 (26.5-29.5 GHz) band of the 5G communication as an example, the bandwidth is expanded by 50% compared with the conventional feeding mode.

What has been described above is only an embodiment of the present disclosure, and it should be noted herein that one ordinary person 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.