Why GaN is 5G’s Super ‘Power’

While some feel GaN is still a relatively new technology, many can’t dispute how it’s advanced to the head of the class. AKA, Gallium Nitride, GaN is a technology on the cusp of dethroning silicon LDMOS, which has been the material of choice in high power applications. GaN is a direct bandgap semiconductor technology belonging to the III-V group. It is increasingly being used in power electronics because of its higher efficiency, superior high-voltage sustainability, reduced power consumption, higher temperature attributes, and power-handling characteristics.

These attributes have thrust GaN into the 5G RF spotlight – especially when it comes to mmWave 5G networks. And, while we all have ‘heard’ the promises of 5G, today, many of us in big cities – about 5 million of us to be more precise – are starting to realize those promises as major wireless carriers roll 5G out to their customers. But we are not there yet. Not even close. The goal is to connect 2.8 billion users by 2025. To reach this goal means to revamp the entire mobile infrastructure – a complex undertaking. But it can be done. And with the help of GaN technology, 5G will be in billions of people’s hands before you know it.

Recently, Embedded.com invited Qorvo’s own Roger Hall to pen a series of 5G articles that explain the complexities of building out the infrastructure and where GaN fits into the innovations that will bring 5G to the masses. Here are summaries of each article with a link for a deeper dive.

5G and GaN: Understanding Sub-6 GHz Massive MIMO Infrastructure

In this article, Roger explains the advantages for carriers to implement Massive MIMO technology as a means to minimize cost and increase capacity when rolling out 5G. He explores sub-6 GHz and why it’s important for increasing the adoption and expansion of 5G. He also addresses how GaN is being used in Massive MIMO Infrastructure applications. Read more >

5G and GaN: The Shift from LDMOS to GaN

Here Roger examines how the power demands of sub-6 GHz 5G base stations are driving a shift from silicon LDMOS amplifiers to GaN-based solutions, and what makes GaN a viable technology for many RF applications. Roger also reviews some of the tradeoffs engineers need to consider between these two technologies and why GaN is becoming the clear winner in many 5G solutions. Read more >

5G and GaN: What Embedded Designers Need to Know

Building on the previous article, Roger provides insight for embedded designers to fully realize the potential of GaN. He discusses misconceptions about GaN, explores its characteristics, and offers best practices to maximize its performance. Read more >

5G and GaN: Future Innovations

In his fourth and final article in this series, Roger looks to the future of GaN’s role in base stations. He provides a peek into GaN innovations being made today that will improve linear efficiency, power density and reliability and the implications of those improvements. Read more >

For more information on GaN technology, visit here.

About the Author

About Roger Hall
Roger Hall

Roger is the General Manager of High-Performance Solutions at Qorvo. He leads program management and applications engineering for Wireless Infrastructure, Defense and Aerospace, and Power Management markets. This overarching role gives him a unique lens to view and interpret where RF technologies play fundamental parts in enabling future innovations.

Qorvo Blog Team

One part technical, one part content, and one part strategic, our small team is dedicated to connecting you with helpful, timely insights from some of the bright minds at Qorvo.

LIDAR – Shaping the future of automotive

LIDAR plays a major role in automotive, as vehicles perform tasks with less and less human supervision and intervention. As a leader in VCSEL, ams is helping to shape this revolution.

LIDAR (Light Detection and Ranging) is an optical sensing technology that measures the distance to other objects. It is currently known for many diverse applications in industrial, surveying, and aerospace, but is a true enabler for autonomous driving. As the automotive manufacturers continue their push to design and release high-complexity autonomous systems, we likewise develop the technology that will enable this. That is why ams continues to bring our high-power VCSELs to the automotive market and to test the limits on peak power, shorter pulses, and additional scanning features which enable our customers to improve their LIDAR systems.

In 2019, ams together with ZF and Ibeo announced a hybrid solution called True Solid State where, like flash technology, no moving parts are needed to capture the full scene around the vehicle. By sequentially powering a portion of the laser, a scanning pattern can be generated, combining the advantages of flash and scan systems.

Making sense of the LIDAR landscape

At ams, we classify LIDAR systems on seven elements: ranging principle, wavelength, beam steering principle, emitter technology and layout, and receiver technology and layout. Here we discuss the first five.

The most dominant implementation to measure distance (ranging) is Direct Time of Flight (DTOF): a short (few nanoseconds) laser pulse is emitted, reflected by an object and returned to a receiver. The time difference between sending and receiving can be converted into a distance measurement. Moreover, with duty cycles of <1% this system takes thousands of distance measurements per second. The laser pulse is typically in the 850-940nm rage, components are readily available and most affordable. However, systems can also be using 1300 or 1550nm, the big advantage is eye safety regulations allow more energy to be used here, and in theory, this provides more range. The downside is that components are expensive.

To scan the complete surroundings (or field of view) of a vehicle, the system needs to be able to shoot pulses in all directions. This is the beam steering principle. Classical systems used rotating sensor heads and mirrors to scan the field of view section by section. As these systems are bulky, they are being replaced by static systems with internal moving mirrors. MEMS mirrors are also about to enter the market. Another approach is flash, where no moving parts are needed at all. The light source illuminates the complete field of view, and the sensor captures that same field in a single frame like a photo. As the full scene is illuminated, and to remain eye safe, this means the range must be limited.

On the emitter side, edge emitters continue to be frequently used, based on earlier developments. They have a high-power density, making them suitable in combination with MEMS mirrors. Where first iterations were single emitters, meanwhile 2-4-8-16 emitters are being integrated in a single bar. Fiber lasers are another interesting technology. They offer even higher power density, and typically are used in 1550nm wavelength and come typically as a single emitter source.

ams is a leading supplier in the VCSEL emitter technology. Our high power VCSELs can differentiate in scan and flash applications as they are very stable over temperature, are less sensitive to individual emitter failures, and are easy to integrate. However, the best characteristic of VCSELs are their ability to form emitter arrays. This makes VCSELs easy to scale. It also allows for addressability, or powering selective zones of the die. This enables True Solid State topology, which we consider to be the most all-rounded LIDAR solution.

LIDAR enables Autonomous Driving

The most commonly accepted way to classify vehicles on their level of autonomy is by the definitions of the Society of Automotive Engineers (SAE). At SAE Level 3 and above, the vehicle takes over responsibility from the driver and assistance turns into autonomy. This means the vehicle should be able to perform its task without human supervision and intervention. This requires a step function in required system performance. Where Level 1 and Level 2 vehicles assist the driver and typically rely on camera or radar, or a combination, there are shortcomings in these technologies for 3D object detection. LIDAR technology addresses this, and there is wide consensus in the industry that from Level 3 onwards, LIDAR is needed for 3D object detection.

When 3D LIDAR is combined or fused with camera and radar, a high-resolution map of the vehicle’s surroundings can be constructed and allow the vehicle to safely fulfil its mission. The automotive industry started with more straightforward driver-assist use cases used in Level 1 and Level 2. As sensors and data processing gets more advanced, further more difficult use cases can be covered, such as Highway Pilot or City Pilot.

Ultimately, when every conceivable use case can be fulfilled by the system we define this as a Level 5 vehicle – fully autonomous and the holy grail of autonomous driving. This is expected to still be quite a number of years out from today. Moreover, there will be huge pressure to bring down cost and rationalize content per vehicle – to make autonomous driving available to the mass market.

Interested to learn more?

Let us know if you would like to discuss how you could be using ams technology to support your potential LIDAR applications!
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