[ADI] 5G changes the RF front-end ecology, and the combined process is expected to reduce design pain

“5G brings more than a mere speed boost. As a unified connection architecture, 5G needs to support diverse spectrums, diverse services and terminals, and diverse deployments within this connection design framework… A media friend interviewed Dr. Thomas Cameron, CTO of ADI’s communications business department, and the editor picked it out for you Part of the essence, see ADI’s interpretation of the status and trends of 5G technology.

“

5G brings more than a mere speed boost. As a unified connection architecture, 5G needs to support diverse spectrums, diverse services and terminals, and diverse deployments within this connection design framework… A media friend interviewed Dr. Thomas Cameron, CTO of ADI’s communications business department, and the editor picked it out for you Part of the essence, see ADI’s interpretation of the status and trends of 5G technology.

Market research agency IHS Markit pointed out in the “5G Economy” research report released that by 2035, 5G will create 12.3 trillion US dollars in global economic output. That’s nearly as much as all U.S. consumers spent in 2016, and more than the combined spending of China, Japan, Germany, the U.K. and France in 2016.

Dr. Thomas Cameron, CTO, ADI Communications Business Unit

5G brings more than a mere speed boost. As a unified connection architecture, 5G needs to support diverse spectrums, services and terminals, and deployments within this connection design framework. Dr. Thomas Cameron, CTO of ADI’s communication business unit, pointed out in an interview with “Electronic Engineering Special” recently that enhanced mobile broadband (above 6GHz frequency band), mission-critical services (1GHz-6GHz frequency band) and massive Internet of Things (below 1GHz frequency band) constitute The core of 5G business.

The “iron triangle” of 5G services

Enhanced Mobile Broadband

Extreme throughput and ultra-low latency are two characteristics of enhanced mobile broadband. Traditionally, 4G technology relies more on licensed spectrum. However, from the initial stage of top-level design, licensed spectrum, unlicensed spectrum, and shared licensed spectrum are planned and designed in a unified manner. Millimeter wave and ultra-massive MIMO will play a key role. Role.

mission-critical services

This type of application has extremely high requirements on reliability, ultra-low latency, and widespread ease of use, such as requiring more than 99.999% reliability and 1ms latency. The current advanced driver assistance system (ADAS) is more of a passive mode of automatic driving, which is completely limited by the knowledge of surrounding information through on-board sensors. But if there is the capability of V2V, a key business service between cars, then the true sense of autonomous driving will be realized.

Massive Internet of Things

Including smart cities, smart homes, monitoring and metering of public facility traffic, wearable devices, remote sensor drives, etc. For example, sensors used in applications such as water meters, electricity meters, and public environmental information monitoring often require no replacement after many years of deployment. The battery life of connected terminals is as long as 5-10 years, and energy saving must be done well; Second, the cost of terminals and chips should be reduced to a few dollars or even lower; the third is deep coverage, that is, supporting scalable coverage capabilities from a long-range perspective.

In the process of network migration from 4G to 5G, the compound growth rate of global mobile data traffic has reached 40%. Operators are under considerable pressure in areas such as network capacity, indoor coverage and spectrum in order to keep up with consumers’ huge demand for data and ubiquitous connectivity.

-Thomas Cameron

Key Technologies to Improve 5G Network Coverage and Capacity

Judging from the deployment of 5G in various countries around the world, the United States tends to use the microwave frequency band, while Asia-Pacific countries such as China, Japan and South Korea mainly focus on the sub-6GHz frequency band. Europe and China have similar ideas. From the perspective of ADI, 5G will take the lead in realizing large-scale deployment in the sub-6GHz frequency band, and small cells (Small Cell) and Massive MIMO will become the key technologies to improve the coverage and capacity of 5G networks.

However, the previous small base station only supported one frequency band, and now it needs to support three to four frequency bands, and the antenna density will also jump from the previous 2T2R/4T4R to 64T64R/128T128R. Although the spectral efficiency can be improved by a factor of 5, the use of such massive MIMO antenna integration will inevitably bring challenges in terms of size, cost and power consumption.

As one of the most comprehensive suppliers of RF and microwave product lines, ADI has successfully acquired companies such as HITTITE Microwave, Symeo GmbH, Innovasic and Linear Technology since 2014. The five areas of transceiver, precision clock and power supply form a complete layout. Thomas Cameron also highlighted ADI’s most iconic products in the interview: the AD9371, the industry’s first AD9375 with integrated DPD functionality, and the RadioVerse technology and design ecosystem launched in May 2016.

Unlike traditional OEMs who still use discrete components (amplifiers, mixers, demodulators, ADC/DAC, filters, etc.) to build so-called SDR platforms, ADI RadioVerse does this by providing integrated RF transceivers, software APIs , design support packages, comprehensive documentation, the ADI EngineerZone online technical support community, and other resources to provide customers with integrated transceiver technology, a robust design environment, and market-specific technical expertise to rapidly move their radio designs from concept to product.

5G mmWave changes RF front-end design

Take another look at 5G access systems in the microwave and millimeter wave bands. One of the biggest barriers to wireless access in the microwave frequency bands (expected to be implemented at 28GHz, 39GHz or 60GHz frequencies) is overcoming the suboptimal propagation characteristics, which are largely affected by atmospheric attenuation, rain, obstacles To overcome the influence of objects (buildings, people, plants) and reflections, to overcome the propagation problems of the access system, adaptive beam-forming (Beam-forming) technology is required. In addition, broadband data conversion, high-performance spectrum conversion, high-efficiency power supply design, advanced packaging technology, OTA testing, antenna calibration, etc., all constitute the design challenges faced by 5G access systems in the microwave and millimeter-wave frequency bands.

Thomas Cameron stressed to reporters the key role that advanced technology plays. As we all know, GaAs has been the mainstream technology in the microwave industry for many years, and first-class microwave systems are usually implemented with GaAs components, but can SiGe technology and traditional CMOS technology have a place?

“It depends on the output power required by each antenna. For example, when the output power is 100mW, GaAs/GaN PA will basically be selected; if the power is only 10mW, the SiGe process can be realized.” But he also reminded that at microwave frequencies Even GaAs PAs are less efficient because they typically shift in the linear region, and SiGe processes are overcoming barriers to high-frequency operation in order to compete with GaAs on multiple signal path functions. At the same time, beamforming technology will reduce the limitations and requirements of PA power transmission, which gives room for CMOS technology to play a role, coupled with CMOS technology has the high level of integration required by beamforming systems, which is very important for many signal chains and auxiliary control. Functionally it’s a boon.

Of course, this also means that the designer must have the ability to integrate components with different performances together. At present, ADI has made extensive technology investments in the above three areas, and has the ability to provide complete solutions from front-end ADC/DAC to back-end antenna arrays.

A final consideration for 5G systems is the interdependence of mechanical design and RF IC segmentation. Up to 50GHz, the antenna will be part of the substrate, and it is expected that routing and some passive structures may be embedded into the substrate; beyond 50GHz, the antenna elements and spacing become small enough to encapsulate the antenna structure, or integrated into the package. Therefore, both the RF IC and the mechanical structure must be designed together to ensure routing symmetry and minimize losses. That said, none of this work would be possible without the powerful 3D modeling tools to perform the extensive simulations required for these designs.