Ensuring good XHaul infrastructure is key to telecoms future

by Dan Rhodes, Director of Business Development, Filtronic

In 2021, mobile network operator EE launched a TV advert showing actor Tom Ellis being shaved by a robotic arm that was being remote-controlled by a barber based 250 miles away — a stunt only possible with low latency and high-speed data transfer capabilities. Here, Dan Rhodes, director of business development at critical communication equipment provider Filtronic, discusses how 5G deployment made possible through critical telecom infrastructure such as XHaul enables the bandwidth and low latency to make this stunt a reality.

The benefits of 5G are transforming the components of traditional telecommunication network infrastructure. Its ultra-fast and low-latency connectivity and potential to deliver data speeds back into the network of > 10Gbps, coupled with the ability to support thousands of clients per cell, puts 5G ahead of current mobile infrastructure — if it delivers to its full potential.

E-band has been a key enabler of XHaul and the transition towards 5G. But it has taken over 10 years to get to this point. Like all new frequency bands, E-band had to overcome cost, availability, and capacity issues to fulfil increased demand. The construct was simple; most cell sites were equipped with backhaul links running at one Gbps or less. Now, the rollout of 5G and its capabilities in both fronthaul and midhaul means that there are two new, distinct XHaul concerns: the necessity for extremely dense networks and addressing the low latency needs of increasingly complex applications.

Backhaul networks may be less impacted by latency specifications than fronthaul and midhaul networks, but backhaul capacity pressure is a significant concern. Backhaul capacity needs for 5G (10-40Gbps) and 6G (target 100Gbps) dwarf existing 4G networks.

While the full implementation of 5G will continue to favour fibre, it won’t be a feasible choice in many areas. Microwave technology is a fast and economical method for connecting isolated or small groups of locations to the main fibre network. The conventional microwave frequency range of 6-42 GHz is facing limitations in expansion due to congestion, interference, and re-use of some bands for RAN, thus leading to a shift towards millimeter-wave (mmWave), specifically  E-Band (71-76GHz / 81-86GHz), the only commercially viable mmWave band at this time.

The E-Band market is projected to grow rapidly worldwide, with a market report predicting a 35.8 per cent CAGR by 2027. E-Band is favoured by operators due to its large channel size and readily accessible spectrum, with over 80 per cent of countries with known telecommunication regulations allowing E-Band deployment. This means that demand has increased for E-Band mmWave radio links due to their ability to provide high capacity and high data rate XHaul for the latest 5G networks that are being rolled out globally.

The E-Band frequency spectrum offers both technical and economic benefits over the lower 6-42 GHz spectrum. Millimeter-wave wireless systems make use of a larger assigned spectrum divided into larger channels, which enables the delivery of multi-gigabit data rates. In comparison, the largest assigned channel in the 6-42 GHz spectrum is 56 MHz, while the smallest typical channel size in the E-Band is 250 MHz and can go up to 2GHz for wireless backhaul.

 With the use of a large allocated spectrum and channels, E-Band wireless systems are more robust and reduce modem and radio requirements, resulting in significant cost advantages over traditional wireless systems. This allows for scaling up to gigabit-per-second capacities without the need for additional radio equipment or licensing fees.

Although it is susceptible to rain attenuation, the sturdy design of E-Band wireless systems and higher antenna gains make it possible to deliver high capacities with a carrier-grade service availability of 99.999 per cent for distances up to three kilometres (km). In urban areas, where the distances between mobile base stations are typically short (averaging 1.5km for urban and 2.5km for suburban), E-Band wireless systems are well-suited for ultra-high XHaul capacities. It’s also worth noting that these urban and suburban areas account for around 80-90 per cent of the elements in a network that require a XHaul solution.

Transceivers that sit in point-to-point radios, like Filtronic’s latest generation Morpheus X2 modules, offer high performance and ultra-high capacity while also lowering the overall cost per Gbps. Each module contains all the transmit and receive functions necessary for the RF section of an E-Band link and provides a simple drop-in connectivity between a high data rate full duplex modem and an antenna.

There are installations where the distance between stations needs to be larger. This could affect commercial viability —for example, implementing larger antennas to boost range has an impact on both material and operational costs. This is where the choice of components used becomes even more important. Higher-power transceivers, like the Morpheus X2, are being used to ensure performance across twelve kilometres of range, without compromising on size or weight.

The demand for data is constantly rising with no signs of slowing down, now or in the future. As mentioned earlier, with 80 per cent of countries allowing E-Band deployment and with more 5G networks being rolled out, it is inevitable that this frequency range will become congested. As E-Band becomes congested, alternative bands with similar or even higher bandwidths available will be required to ensure that XHaul capacity can keep pace with increasing data demands. These bands will be W-band (92-114GHz) and D-band (130-175GHz).

Filtronic has been involved in a collaborative project with the UK National Physical Laboratory (NPL) on next-generation mmWave technology for W-Band and D-Band systems up to 175GHz – to enable emerging 5G wireless XHaul requirements up to 100Gbps.

Moving up the frequency spectrum from E-Band to W-Band and D-Band systems, where huge amounts of further bandwidth are available, is seen as part of the solution to increasing data capacity to meet global demand. But until then, network operators must size appropriately the Xhaul network to cope with the massive amount of data and opportunities generated by 5G using mmWave technology, now and in the future.

• RF Solutions for Public Safety Critical Communications
• Aerospace and defence applications
• Telecommunications
• RF Solutions for Space
• RF Testing and Measurement

by Tudor Williams, Director of Technology, Filtronic

In the ever-evolving landscape of technology and industry, one finite resource remains the unsung hero in enabling our modern way of life – the radio frequency (RF) spectrum. Here Tudor Williams, Director of Technology at Filtronic, explores how demand for wireless broadband access has highlighted the limitations of this essential resource.

The explosive growth of wireless broadband is poised to reshape our world. With more than one billion 5G subscriptions anticipated by the end of 2022, skyrocketing to a forecasted 4.4 billion by 2027, the implications are far-reaching. Entire industries rely on fast and reliable mobile broadband access – and new industries will open up and expand when high-speed and low latency access becomes widely available. Tasks such as remote surgical procedures performed by surgeons worldwide will become reality, emerging technologies like driverless cars will be ever-present and all require uninterrupted, rapid data transfers.

While the world focuses on dwindling natural resources, the RF spectrum quietly fuels the functioning of virtually every aspect of society and industry through radio waves at microwave and millimetre wave frequencies.

However, the crux of the matter is the limited availability of the RF spectrum for these crucial applications. This precious resource is becoming increasingly scarce, and existing licensed frequency bands are becoming congested. The existing bands can be optimised further through innovative techniques like dual polarisation, higher-order modulation, and MIMO (Multiple Input, Multiple Output). However, these solutions have their limitations, especially as we move into higher-frequency ranges.

To ensure the RF spectrum’s ability to support our data-intensive future, the industry is investigating various approaches. These include optimising the use of current licensed bands through enhanced filtering, encoding, and separation techniques, although these improvements yield diminishing results. Another avenue involves using unlicensed frequencies, although this presents challenges related to competition and reliability due to the lack of regulation. However, the most significant solution lies in the exploration of higher millimetre wave bands (above 86GHz), where expansive and uninterrupted bandwidth offers a groundbreaking capacity boost.

While transitioning to higher frequency bands offers a promising solution, it brings along its own set of challenges. Atmospheric absorption increases, attenuating signals and reducing transmission distances. Additionally, manufacturing sub-systems for higher frequency bands becomes intricate due to tighter tolerances and smaller geometries. Availability of suitable semiconductors at these frequencies and power generation also remain critical hurdles.

In this pursuit of optimising the RF spectrum, collaboration between technology specialists and innovators becomes paramount. For companies pushing the boundaries of RF technology, these challenges are opportunities. By harnessing compound semiconductor processes like gallium arsenide (GaAs) and gallium nitride (GaN), companies can pave the way for higher-frequency communications. These advancements, combined with standard-setting by global industrial nations, could be the cornerstone of an efficient and uncongested RF communication network.

As we hurtle toward 6G and beyond, the quest for more efficient and reliable data communications becomes non-negotiable. Industry players like Filtronic are at the forefront, pioneering advancements in semiconductor processes and packaging techniques to enable the transition into higher frequency bands. As we collectively address these challenges, our ability to provide high-speed, low-latency communication solutions for applications across industries grows stronger.The RF spectrum plays a pivotal role in our interconnected world. While challenges loom, they’re surmountable through collaboration, innovation, and strategic advancements. The journey toward higher frequency bands is one that holds promise, offering the potential to revolutionise everything from healthcare to transportation. So, whether you’re in the telecoms industry, defence, aerospace, or any field touched by RF communications, the future is bright — driven by the determination to maximise this finite resource and meet global data demands head-on.

Find out more about Filtronic’s capabilities:

• RF Solutions for Public Safety Critical Communications
• Aerospace and defence applications
• Telecommunications
• RF Solutions for Space
• RF Testing and Measurement

by Adele Pliscott, SiP Packaging Engineer, Filtronic

Not all OSAT providers are the same

Many semiconductor suppliers and electronics companies work with outsourced semiconductor assembly and testing (OSAT) partners to manufacture specialist devices for specific industries. But not all OSAT companies are the same. When you need to provide control and monitoring devices for the most challenging high-temperature applications, you need to choose an OSAT partner that can consistently deliver high-reliability hybrid products for the harshest environments.

Some of these challenging applications include control and power modules located close to engines in aircraft, or sensors used in the oil and gas sector to monitor drilling operations. In all of these applications, high reliability is the primary requirement. Not every OSAT provider can deliver the hermetic hybrid electronic products required for such high-performance applications.

High-temperature applications demand a different approach 

Standard hybrid assemblies for applications below 150°C have been manufactured for many years using well-understood material sets. For temperature ranges above 150°C, however, specialist expertise is required to achieve the performance and reliability levels required.

It’s important to recognise that high reliability at high temperatures is linked to the way products are processed, not just their design. Specialist high-reliability OSAT partners take designs and schematics provided by clients – which are generally based on PCBs – and reconfigure them to create compact hybrid solutions with form, fit and function, designed for high-reliability, long-life performance.

So what differentiates an OSAT provider capable of delivering high-reliability hybrid electronics from a standard OSAT company?

– Materials selection

A key factor in achieving high reliability is the selection of materials. Most standard hybrid modules are built using epoxies as an adhesive for the components. However, the resins used in epoxies decompose with temperature and time, leading to outgassing from the module and ultimately the corrosion and mechanical breakdown of the electronics within.

To overcome this problem in higher temperature applications, material sets need to be selected for low outgassing, high structural strength and greater control of intermetallic interactions. This means choosing metal layers for the substrate that match the components and material you’re adhering to.

– Component selection

Alongside material selection, selecting the right components is the next critical step to ensure maximum product life. It’s important to avoid mismatches in coefficients of thermal expansion (CTE) between the joining materials and the selected components. CTE mismatches are the primary cause of most electronic failures within modules. To mitigate these stresses, specialist knowledge is required to select the appropriate joining materials.

– Precision manufacturing

Achieving extremely high reliability also requires precision manufacturing in a controlled environment. Order quantities for these complex modules tend to be small, but the costs are relatively high. To maximise accuracy and consistency in every module, component placement needs to be extremely precise. OSAT partners capable of manufacturing hybrid electronics for high-temperature applications will use fully automated dispense and component placement machinery, and implement rigorous visual and manufacturing processes.

Producing robust hermetic hybrid electronics means working beyond the current military standards. Manufacturing and testing components to perform at high temperatures means effectively working to bespoke standards, enabling products to be tailored to perform reliably in the most challenging conditions.

– Test

Depending on the functionality of the hybrid module some level of expertise and engineering capability is required to develop, maintain, and deliver robust end-of-line product test. The OSAT supply of optical modules, power modules or high-frequency RF hybrids requires a high level of subject matter expertise and access to state-of-the-art test equipment. Choosing a supplier with a strong track record in the technology is vital for a full turnkey OSAT solution.

– Traceability and accountability

Filtronic leverages its in-house Manufacturing Execution System (MES) software to track every aspect of the manufacturing process including materials, components, and labour.  Filtronic’s cloud-based software provides real-time data capture and analysis of multiple indicators at each step in the manufacturing process. Filtronic tracks production efficiency and other valuable KPIs. The MES also enables tracking of individual components or assemblies using bar codes which triggers the next station to prepare for assembly downstream. Filtronic’s MES is an essential tool for our production planners to identify where each unit or lot is within the manufacturing cycle, what materials are needed, and when.

Hybrid electronics for extreme applications

Very few OSAT providers have the in-house knowledge and experience to design, manufacture and test high-reliability electronics to such exacting standards. At Filtronic, we specialise in developing bespoke and customised electronics for specific clients and applications.

We have a track record of delivering reliable, high-performance components for the aerospace, defence and space sectors. That means we have the process knowledge, materials expertise and manufacturing capabilities to deliver high-reliability components with the necessary properties to perform consistently in extreme environments.

If you are looking for an OSAT partner for a challenging application like Oil & Gas or Aerospace, or if you are looking for a market leading RF OSAT partner, contact the specialists at Filtronic who can offer the expertise and advice you need.

Find out more about Filtronic’s capabilities:

• RF Solutions for Public Safety Critical Communications
• Aerospace and defence applications
• Telecommunications
• RF Solutions for Space
• RF Testing and Measurement

by Adele Pliscott, SiP Packaging Engineer, Filtronic

Outsourced semiconductor assembly and testing (OSAT) companies provide specialist manufacturing capabilities for semiconductor suppliers serving specific industries. Outsourcing your manufacturing and testing to a specialist provider can enable you to manufacture more complex devices, optimise costs and efficiencies, access niche expertise, reduce production time, increase output and allow you to focus on your core specialisms.

The relationship you develop with your OSAT partner is critical to your success in delivering the complex semiconductor assemblies required by your clients. When you are providing hybrid electronic products for extremely challenging high-temperature applications, such as those in oil and gas or aerospace environments, choosing the right OSAT partner can be key to delivering the innovative, high-reliability control and monitoring equipment your clients demand. This is not a traditional Contract Manufacturing Service or a build-to-print activity, it involves a much more integrated partnership-led approach.

There are a number of attributes, skills and capabilities to look out for when choosing an OSAT partner to deliver complex hybrid electronic products.

Access to technical expertise

Not only do you want to find a company that has the technical skills and knowledge to help you design and manufacture hermetic hybrid electronics, you need a partner that gives you direct access to those specialists. Developing the kinds of complex electronic products currently being pioneered in the oil and gas sector requires a process of continuous collaboration, knowledge sharing and testing. You want to work with an OSAT organisation that allows you to build direct working relationships with its technical specialists.

Track record in complex microelectronic engineering

The oil and gas sector is breaking new ground in the development of electronics used for monitoring in-situ drilling and well barriers. Drill monitoring places electronic devices in high-temperature, high-vibration environments, while devices used to monitor well barriers can be encased in concrete for up to 15 years, meaning long-life reliability is key. In aerospace, clients are looking to develop near-engine controllers, which must operate reliably in extremely high-temperature locations.

Choosing an OSAT partner to manufacture products for these applications means finding a provider with experience in designing and manufacturing similarly complex devices.  A partner with a proven track record in comparable high-performance applications such as the defence, aerospace or space sectors. A successful long-lasting partnership can be achieved by choosing a partner with a proven track record of consistently delivering high-quality results and ongoing improvements in yield above 98%.

Materials and component knowledge

Manufacturing hybrid electronic systems to deliver high reliability at high temperatures requires an in-depth knowledge of materials and components. You need a partner who knows how to specify the right materials and components to prevent intermetallic contamination, reduce the risk of corrosion and maintain structural integrity in harsh operating conditions – for many years.

Compliance with challenging standards

Look for an OSAT partner that can manufacture and test microelectronics to the strictest regulatory standards. For oil and gas applications, your partner needs to work to Advanced Well Equipment Standards (AWES) as a minimum. Existing military (MIL) standards provide a more robust framework, but the demands of high-temperature applications above 150°C mean your OSAT partner will need to work to standards that go beyond MIL. You need a partner that has the most rigorous in-house testing capabilities, which can be customised to meet challenging standards and achieve external qualifications. Full traceability throughout the process is critical, as is a facility that provides full compliance for secure or classified materials.

Agility and adaptability

Requirements and expectations for control and monitoring equipment move quickly in the oil and gas sector, where these components are in their infancy. Choosing an OSAT partner that combines design and manufacturing excellence with the ability to customise processes quickly in response to new challenges will help to keep you ahead of the competition. Look for a partner that allows you to work engineer-to-engineer, giving you the flexibility to innovate at pace. Such mutually supportive teamwork is essential in an industry that is constantly pushing the boundaries of microelectronics.

End-to-end capabilities – from design to testing

Your ability to collaborate, innovate, optimise efficiencies and achieve repeatable standards will be greatly enhanced if you choose an OSAT partner that offers complete end-to-end capabilities in-house. That means finding a partner with design, manufacturing and testing expertise and facilities under one roof. If your partner also has excellent supply chain connections and close working relationships with materials suppliers, the risks of delays and interruption to production processes are significantly reduced. When it comes to RF products, it’s crucial to choose an RF partner for OSAT work because of their complicated nature. The OSAT partner must have the necessary skills and facilities to ensure maximum success.

Proven OSAT solutions with Filtronic

At Filtronic, we have been working with technical leaders in some of the most demanding industries for many years, helping them to manufacture precision hybrid microelectronics to exacting standards. Our process understanding sets us apart in the market – we recognise that achieving high reliability requires not just excellence in design but also in processing.

With all this expertise in-house, we have the capabilities to manufacture complex electronics to repeatable standards for applications where thermal management and reliability are paramount. This has enabled us to build collaborative working relationships with industries that are pioneering new applications for hybrid semiconductor modules.

If you are looking for an OSAT partner for a challenging application like Oil & Gas or Aerospace, or if you are looking for a market leading RF OSAT partner, contact the specialists at Filtronic who can offer the expertise and advice you need.

Find out more about Filtronic’s capabilities:

• RF Solutions for Public Safety Critical Communications
• Aerospace and defence applications
• Telecommunications
• RF Solutions for Space
• RF Testing and Measurement