day The line is an important part of the base station, which is composed of the radiation unit (oscillator), the reflector plate (bottom plate), the power distribution network (feed network), and the packaging protection (radome). The antenna is a converter that converts the navigation wave propagating on the transmission line into an electromagnetic wave propagating in an unbounded medium, or the reverse transformation. Whether it is a base station or a mobile terminal, the antenna is used to transmit and receive electromagnetic waves. The performance of the base station antenna directly affects the quality of mobile communication.

2, PCB

PCB (Printed Circuit Board) is printed and connected to other electronic components of the bridge, is an indispensable product in the modern electronic information industry. 5G era base station with PCB will tend to more layers of highly integrated design, in addition to structural changes, 5G data volume is larger, the transmission frequency is larger, the working frequency band is also higher, which requires the base station with PCB board has better transmission performance and heat dissipation performance, so 5G base station with PCB board to use higher frequency, higher transmission speed, better heat resistance of the electronic substrate.

PCB industry chain from upstream of the copper foil, glass fiber, copper clad, middle of PCB manufacturing and downstream of the industry application. Copper clad board directly affects PCB conduction, insulation, support and other functions, is an important substrate for PCB manufacturing, accounting for the highest cost of PCB raw materials.

3, filter

Base station filter is a key component of the radio frequency system, the main working principle is to send and receive signals in the specific frequency components through, and greatly attenuating other frequency components. In the 3G/4G era, the metal coaxial cavity has become the mainstream choice of the market with a lower cost and a more mature process. In the 5G era, limited by MassiveMIMO's requirements for large-scale antenna integration, ceramic dielectric filters have advantages in miniaturization, lightweight, low loss, temperature stability and cost performance, and ceramic filters have gradually become the mainstream of the market.

ceramic filter core manufacturing technology mainly includes the powder formula, forming and sintering, metallization and debug the four links. The difficulty of production technology lies in consistency. The formula of ceramic powder materials, the automation of production and the yield and efficiency of debugging are the difficulties of filter production.

In the 4G era, base station filter enterprises mainly supply directly to equipment manufacturers, and in the 5G era, the main equipment manufacturers integrate antennas & Filter manufacturers or become a trend, antenna and filter integrated into an integrated AFU program or become the development of AAU and small base stations in the 5G era. In the early stage, the miniaturized metal filter with mature technology will be adopted, and the ceramic medium filter will be the choice of most main equipment manufacturers in the later stage.

5 g phones

1, 5 g antenna materials - LCP and MPI

5 g drive is opportunity for the development of smart antenna and innovation . With the development of the Internet, the frequency of radio waves used in cell phone communication has gradually increased. Because the electromagnetic wave has the characteristics of higher frequency, shorter wavelength and easier attenuation in the propagation medium, the higher frequency, the smaller the loss of antenna material is required.

The earliest antenna was made of copper and alloys and other metals, and later with the emergence of the FPC process, the antenna manufacturing material in the 4G era began to use PI film (polyimide). However, PI loss above 10Ghz is obvious, can not meet the needs of 5G terminals, with the meson loss and conductor loss is smaller, with flexibility, sealing and other characteristics, LCP (Liquid Crystal Polymer, liquid crystal polymer) gradually applied. However, LCP is expensive and complicated. At present, MPI (Modified Polyimide) is expected to become one of the mainstream choices for antenna materials in the early 5G era.

the LCP is mainly used to such as unmanned need quick response and AR, VR application scenarios of the large capacity transmission. LCP can be usedHigh frequency circuit board, COF substrate, multilayer board, IC package, u-BGA, high frequency connector, antenna, speaker substrate, lens module /FPC, phase shifter small projector, etc.

Modified polyimide (MPI) non-crystalline material, basically can be operated at a variety of temperatures, especially at low temperature pressed copper foil, can be easily followed by the surface of copper. Its fluoride formula has been improved, in 10G ~ 15GHz ultra-high frequency and even extremely high frequency signal processing performance is expected to be comparable to LCP antenna, MPI can meet the signal processing needs of the 5G era, and the price is more affordable than LCP, so in the early stage of 5G development, MPI is expected to replace part of the PI, become an important transition material.

2, semiconductor materials

5G will bring revolutionary changes in semiconductor materials, with the migration of communication frequency band to high frequency, base stations and communication equipment need to support high-frequency performance of RF devices, GaN advantages will gradually become prominent.

At present, the proportion of transverse diffusion metal-oxide semiconductor (LDMOS), gallium arsenide (GaAs) and gallium nitride (GaN) in the field of telecommunications base stations is not much different. From the perspective of future development trend, 5G communication frequency can reach up to 85GHz, which is the frequency band for GaN to play its advantages. Making GaN is expected to become one of the key materials for 5G base station construction. In addition, as GaN single crystal substrate research technology tends to mature, the next development direction is large size, high integrity, low defect density, self-supporting substrate materials.

3, thermal conductive materials

Thermal conductive materials are mainly used to solve the heat dissipation problem of electronic equipment, for the contact interface between the heat source and the radiator, through the use of thermal conductivity is much higher than the air thermal interface materials, improve the heat dissipation efficiency of electronic components. The new products in the 5G era have the characteristics of ""high heat flux, high power, stability, thermal response, and ultra-thin"", which puts higher requirements on heat conduction and heat dissipation materials.

4, electromagnetic shielding material

electromagnetic wave caused by electromagnetic interference (EMI) and electromagnetic compatibility (EMC) problems are becoming more and more serious, not only to electronic instruments, equipment caused interference and damage, affect its normal work, but also pollute the environment, endanger human health. In addition, electromagnetic wave leakage will also endanger information security. Electromagnetic shielding is the use of shielding materials to block or attenuate the electromagnetic energy transmission between the shielded area and the outside world, the principle is that the shielding material reflects and absorbs electromagnetic waves. Electromagnetic shielding materials solve electromagnetic interference and electromagnetic compatibility problems caused by electromagnetic waves.

According to the preparation process of the material, electromagnetic shielding materials can be divided into metal electromagnetic shielding materials, filled composite shielding materials, surface coating shielding materials and conductive coating shielding materials.

The current IMT and back cover PC injection molding + coated plastic shell in the appearance of the texture has been a qualitative leap, plastic-related enterprises in the protective shell market there is still a lot of room to rise 5G mobile phone backplane material choice, need to consider 10 indicators, of which 6 performance indicators, 3 mass production feasibility indicators, comprehensive indicators 1.

With the commercial use of 5G, the elimination rate of the metal mobile phone back shell will be further accelerated, and glass/ceramics/plastics will become the three main raw materials.

PMMA + PC composite plate of raw materials and low cost, and easy processing, resistance to fall off not easily broken deformation; Through texture design and 3D high pressure molding can achieve 3D glass effect, the surface visual texture is greatly enhanced; The backplane has good wear resistance and toughness.

Ceramic material combines the appearance differentiation of glass, no signal shielding, high hardness performance advantages, and has excellent heat dissipation close to metal materials. The application of zirconia ceramics in mobile phones is mainly the back cover, fingerprint recognition patch or wearable device shell, lock screen and volume key and other small structural parts. As a mobile phone shell material, ceramic has good texture, good wear resistance and good heat dissipation performance, which can well meet the requirements of 5G communication and wireless charging technology for fuselage materials.