Low dielectric constant materials for 5G communication base stations
Contents
Summary
- Key features of 5G networks include (1) ultra-high speeds, (2) ultra-low delays, and (3) large numbers of simultaneous connections.
- 5G networks use high-frequency electromagnetic signals that are highly susceptible to attenuation, making large transmission losses a problem. Addressing this issue requires rethinking the materials used to construct network hardware components.
- Asahi Kasei recommends our XYRON™ modified polyphenylene ether resins as materials for 5G network components, including smartphone and base stations.
The evolution of mobile networks and the road to 5G
Mobile networks have evolved in tandem with progress in cellular device technology and the explosive growth in data-transmission volumes.
The field began with the first generation (1G) of analog wireless networks in the 1980s, which made possible the first mobile voice conversations.
The transition to digital networking proceeded through the 2G networks of the 1990s, an era in which the use of mobile data services—driven primarily by e-mail—became widespread.
In the 2000s, 3G networks enabled a dramatic increase in data speeds, allowing sharing of static images and birthing the first mobile web browsers; it was during this time that globally standardized digital protocols were adopted as networking standards.
The 2010s saw the emergence of smartphones, which became increasingly ubiquitous together with 3.9G long-term evolution (LTE) networks. Meanwhile, since 2015 the LTE Advanced standard has enabled a broad rollout of 4G networks —a trend that continues to the present day.
The hotly anticipated next step in the evolution of communication standards is 5G networking, whose rollout is currently underway.
Features and challenges of 5G networks
The three most important advantages of 5G networks are as follows.
Advantages of 5G networks
- eMBB (enhanced Mobile Broadband)：Ultra-high speed, high-volume communication
- URLLC (Ultra-Reliable and Low Latency Communications)：Ultra-high reliability and low delay
- mMTC (massive Machine Type Communication)：Large numbers of simultaneous connections
5G networks are expected to offer maximum data-transmission speeds at least 10 times greater than those of 4G networks.*1
5G networks use higher-frequency electromagnetic signals than previous network generations. In Japan, for example, 4G networks use frequencies in the platinum band (700-900 MHz) or the primary band (1.5-3.5 GHz), while 5G networks primarily use the Sub6 (3.7, 4.5 GHz) and quasi-millimeter (28 GHz) bands. The use of higher-frequency signals comes at some cost: the attenuation of electromagnetic signals is proportional to the frequency squared*2, so high-frequency signals suffer much greater losses than low-frequency signals—and greater difficulty in reaching their intended destination. This poses challenges for network connectivity, and can serve as an obstacle to ensuring reliable communications.
For this reason, 5G networks require more base stations than previous generations, and 5G smartphone terminals must incorporate higher-performance radio systems to ensure satisfactory communications.
*1: 5G networks offer data transmission at rates of 10 Gbps, compared to 1 Gbps for 4G networks.
*2: Friis transmission equation
Performance requirements for 5G network components
The nature of 5G networking requires that hardware devices be designed to minimize attenuation of high-frequency electromagnetic signals.
This, in turn, demands that the components of these devices be made from materials with low relative dielectric permittivity and a low loss tangent.The relative dielectric permittivity and loss tangent of a material are physical properties that control the attenuation of electromagnetic signals in the material; materials with high permittivity or high loss tend to absorb electromagnetic signals, increasing signal losses and degrading communication sensitivity.
The specific challenges of 5G networking demand new levels of ingenuity in designing network hardware, including minimizing electromagnetic signal attenuation in the cases or chassis in which hardware components are enclosed and optimizing the layout of those components to further reduce electromagnetic interference.
Achieving high reception sensitivity in 5G networks requires nothing less than a comprehensive approach in which the design of each individual component is optimized for maximal performance.
Asahi Kasei’s Recommended Solutions
XYRON™ for 5G networking
Asahi Kasei recommends the XYRON™ modified polyphenylene ether (PPE) resins as materials for 5G network components, including smartphone terminals and base stations.
What is XYRON™?
XYRON™ is polymer alloy combining polyphenylene ether (PPE) with other resins. Asahi Kasei's
The XYRON™ family, which Asahi Kasei has been producing since 1979, boasts an extensive track record—occupying a key role in the history of engineering plastics—and today encompasses an extensive lineup of polymer alloys.
XYRON™ offers multiple excellent physical properties.
In addition to their high heat resistance, they boast excellent flame retardance and electrical insulation, dimensional stability, and water resistance, as well as low specific gravity. These polymer alloys combine the advantages of PPE with the specialized properties of various other resins to yield unique functional materials.
To date, XYRON™ has been used to make components and cases for a wide range of industrial sectors, from automobiles to household appliances.
For automobiles, in particular, the combination of low specific gravity with high heat resistance and flame retardance has made the use of XYRON™ a popular strategy for reducing the weight of on-board components.
Wide lineup of modified PPE resin XYRON™
Why choose XYRON™?
The parent material of all XYRON™ products is polyphenylene ether (PPE), whose low dielectric permittivity and low loss tangent make it well-suited for use in information and communications field.
PPE also features a high glass transition temperature, and its dielectric properties are less temperature-dependent than those of other high heat-resistant resins. These are important advantages for ensuring stable, high-quality communication across a wide range of operating temperatures.
Comparison of dielectric properties of each engineering plastic (non-reinforced)
Antenna covers for 5G base stations
AA181-7(Developing code name*): A XYRON™ material innovation
Asahi Kasei recommends AA181-7 (Developing code name*), XYRON™ developing grade, for antenna covers in 5G base stations.
AA181-7 (Developing code name*)is a XYRON™ developing grade with excellent hydrolysis resistance and shock resistance that is available in all colors and is compliant with the UL94V-0 flame-retardance standard.
Antenna covers—the outermost layers of antenna assemblies—require lightweight, weather-resistant materials with low dielectric permittivity to improve electromagnetic-wave transmissivity. AA181-7 (Developing code name*) simultaneously offers low dielectric permittivity and compliance with the UL94V-0 flame-retardance standard, which is difficult to achieve using conventional materials.
Modified PPE Resin "XYRON™" Compatibility of UL94V-0 Flame retardance Standard and Low Dielectricity
To date, antenna covers have typically been made from polycarbonates (PCs) or similar materials, but this choice leaves much to be desired from the standpoint of dielectric properties. We recommend to use AA181-7 (Developing code name*) for antenna covers which may eliminate such problems.
Asahi Kasei is also developing additional XYRON™ grades for various types of equipment covers, including grades that resist color changes induced by light exposure. The XYRON™ family of materials is the right choice to satisfy a wide range of specifications for 5G base-station antenna covers.
*Please note that XYRON™ development material "AA181-7" is only a tentative name in the development stage, and the grade name will change when it is officially commercialized in the future.
RF cavity filters for 5G base stations
Asahi Kasei is developing XYRON™ grades for RF cavity filters in 5G base stations.
Base stations commonly incorporate large numbers of metal or ceramic RF filters that increase system weight, complicating installation, and increasing operating losses. The greater density of base stations required for 5G networks makes these factors even more important—and creates an urgent demand for lighter-weight components.
XYRON™ grades for RF filters—specifically designed for applications to RF cavity filters in 5G base stations–offer high heat resistance, good plating properties, and low linear-expansion coefficients comparable to those of metallic materials, facilitating your transition to resin-based RF filters.
These resin materials are ideal replacements for metals for reducing the weight of components demanding dimensional stability in a variety of operating temperatures, and a low coefficient of linear thermal expansion over a broad temperature range.
Introducing controlled-permittivity compounds from Asahi Kasei
The unique low-permittivity properties of PPE, in combination with Asahi Kasei’s compound-material technology, have allowed us to develop new resin grades with well-controlled dielectric permittivity.
Dielectric materials have wavelength-shortening properties, and have found use in a variety of applications, including dielectric phase shifters and antennas, where the use of high-permittivity (high Dk), low-loss (low Df) materials can reduce size and weight of components.
However, conventional materials offer a tradeoff between high Dk and low Df, and achieving both simultaneously is difficult. To achieve both high Dk and low Df in the same material, Asahi Kasei is developing XYRON™ grades with carefully controlled Dk and Df. These resins are ideal for fabricating miniaturized antennas or dielectric phase shifters for use in base stations.
Dielectric phase shifter for base stations
By proposing dielectric property grades that meet customer needs, we will contribute to the further enhancement of the functionality of next-generation communication base stations.
Wide Range of Dielectric Properties of Modified PPE Resin XYRON™
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Video Presentation
Asahi Kasei’s XYRON™ materials for 5G networks
5G / IoT communication exhibition Asahi Kasei 's efforts Watch video
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We would like to talk to you about Asahi Kasei’s XYRON™ for 5G networks.
Please contact us to ask any questions, discuss any concerns, and request samples.
