The RF/Microwave Industry in the UK and Ireland, Birthplace of Radar and the GaAs MMIC

After a year of unprecedented compromises, which nevertheless accelerated the pace of technological progress, European Microwave Week (EuMW) returns to London in February for the first time since 2016. This review of the microwave marketplace in my home country is inevitably a more personal one than those in previous years. In addition to profiling some of the main players in the market in 2021, I will reflect on some of the home-grown heroes of the microwave industry in the U.K. and Ireland who have influenced my own career and whose achievements continue to shape the landscape today.

HISTORICAL LANDMARKS

Figure 1 Roadside plaque in Stowe Nine Churches, Northamptonshire, commemorating the first demonstration of radar. Source: Wikimedia Commons.

Within a 20-mile radius of where I live in rural Northamptonshire, in England’s East Midlands, are three significant landmarks in the history of RF. Firstly, there is the tiny village of Stowe Nine Churches, where a plaque by the roadside (see Figure 1) commemorates the 1935 experiment when Robert Watson-Watt and Arnold Wilkins used the signals from the nearby BBC radio transmitter at Daventry to demonstrate the feasibility of radar. The local historical connection continues with the world-famous Bletchley Park, where the codebreakers of World War II intercepted German communications and cracked the code of the Enigma machine, giving the U.K. and its allies a critical advantage that helped shorten the war.

Finally—and the reason I originally moved to this part of the country—there is Caswell, the former Plessey research center near Towcester (now owned by photonics manufacturer Lumentum), where the late Jim Turner developed the first commercially-available RF GaAs FET in 1970. In 1976, Turner led the team that included Ray Pengelly, who demonstrated the world’s first GaAs MMIC. Caswell was still basking in the glory of these achievements when I started work there as a new graduate, in August 1977, the same week as the late Tom Brazil, who subsequently was a professor at University College Dublin, chaired the 2006 European Microwave Conference and was elected president of the IEEE MTT-S.

The Caswell site’s involvement in MMICs continued until the GaAs line was shut down in 2004, by which time it was trading as Bookham Technologies.¹ Several microwave companies trace their roots to the Plessey legacy and remain in the Northamptonshire area: Microwave Technology designs and manufactures GaN power amplifiers (PAs) with output power to 56 dBm at X-Band, as well as offering design consultancy services. Enterprise Control Systems designs and manufactures RF surveillance and countermeasure systems for military and security applications, including bi-directional coded orthogonal frequency-division multiplexing data links and the AUDS C-UAS RF inhibition systems that counter both small consumer and long-range winged drones. SJ Technologie designs passive RF and microwave components and distributes a range of ferrite, garnet, dielectric and load materials.

On the former Plessey site in Towcester, the BAE Systems Microwave Materials facility researches low-observable and adaptive stealth technologies and manufactures materials to improve the radar cross section of military platforms, including jet aircraft, UAVs, weapons, ships and submarines. Radomes and test hoods are part of its product portfolio. Intelliconnect has a manufacturing facility in Corby, Northamptonshire, where it produces standard and custom RF connectors and adapters, cable assemblies and specialist cryogenic connectors. Amphenol, a global manufacturer of antennas for base stations and small cells, has its U.K. manufacturing facility in Wellingborough.

LINCOLN

A similar pocket of microwave businesses grew up in the Lincoln area, resulting from the various GEC-Marconi sites formerly there. These include Linwave Technology, which manufactures microwave and mmWave subsystems—including sources, LNAs, SSPAs and control modules to 94 GHz—primarily for satellite communications (satcom), defense and industrial applications. Teledyne e2V has facilities in both Lincoln and Chelmsford, Essex, and manufactures RF power devices from magnetrons to semiconductors. Under development are dual-channel digital-to-analog converters (DACs) capable of operating into Ka-Band, migrating RF hardware into code, supporting beamforming and enabling dynamic RF system reconfiguration on the fly. The DACs have a 25 GHz output bandwidth at 3 dB attenuation, with much wider bandwidth if slightly higher attenuation can be tolerated. Each DAC has built-in signal processing, including a programmable anti-sinc filter, direct digital synthesis, a programmable complex mixer and digital up-converter.

LONDON AREA

Unusual as it may seem, the U.K.’s capital city has relatively little microwave industry within its boundaries. An exception is the National Physical Laboratory (NPL), situated just south of the River Thames in the suburb of Teddington. NPL is the U.K.’s National Measurement Institute and is concerned with scientific measurements in all disciplines. This year’s EuMW General Chair Nick Ridler and several of the members of his committee work for NPL. The Electromagnetics group at NPL focuses on providing accurate and repeatable measurements of electromagnetic parameters traceable to the SI system. This work is growing in importance as many 5G use cases rely on accurate and traceable measurements at RF, microwave and mmWave frequencies; NPL’s work helps test, validate and bring to market new technology innovations. TMD Technologies also has a London base, where it manufactures microwave power modules, traveling wave tubes, high voltage power supplies and rugged instrumentation amplifiers for radar, EW, communications, electromagnetic compatibility, scientific and medical applications.

Figure 2 Anechoic chamber at Chelton’s Marlow antenna facility.

The counties immediately surrounding London—the so-called Home Counties—house a number of establishments with microwave expertise. Chelton (formerly Cobham Aerospace Connectivity) has design, manufacturing and test facilities at Marlow in Buckinghamshire and Newmarket in Suffolk, where it produces antennas for air, land and sea platforms, as well as RF components such as diplexers, splitters and couplers. Chelton’s anechoic chamber at Marlow is shown in Figure 2. In November 2021, to support its R&D activities, Chelton opened a new research facility at the former Redhill Aerodrome in Surrey. The Redhill site is the design center for Chelton’s ground penetrating radar, which is embedded in the company’s stand-off mine and IED detection equipment as well as in the latest generation of Minehound and Wirehound detectors manufactured by Vallon. Engineers at Redhill are also developing 5G and 4G LTE technology for use in the U.K.’s airborne public safety program for emergency services.

The U.K. site of API Tech—also formerly part of Cobham—is in Milton Keynes, where it designs and makes active electronically scanned array radar systems, along with high reliability subsystems, modules and components for defense and space. Spacechips in Harpenden is a startup targeting the space industry with products that include L- to Ku-Band ultra-high throughput on-board processors and transponders for satcom, aiming to make payloads smaller, lighter and less power consuming. It also offers design consultancy services for manufacturers of satellites and spacecraft.

In Stevenage, the Wireless Business Unit of Viavi Solutions manufactures the TM500 Network Tester, which is used by virtually every wireless base station manufacturer. Earlier this year it unveiled TMLite, a streamlined version that delivers features, a software environment and user experience consistent with the TM500 but is hosted on a commercial off-the-shelf server. This enables infrastructure vendors to identify software errors by deploying focused functional test tools earlier in the development cycle, in a more compact package than the standard product. Another test manufacturer, Anritsu, has its U.K. base in Luton, comprising software development, sales and support.

CAMBRIDGE CLUSTER

The Cambridge area is a renowned hub of technology innovation, home to both ARM and the Qualcomm site that was formerly Cambridge Silicon Radio. Huawei also has its U.K. R&D center at the Cambridge Science Park. Design consultancies and innovative start-ups are a specialty, the best known probably Cambridge Consultants, which was founded in 1960 to connect the academic excellence of Cambridge University with business and industry. Covering a wide range of technical disciplines, including RF, it has created more than 20 successful spinout ventures, including Cambridge Silicon Radio.

PRFI, with offices and labs near Cambridge, is a technical design consultancy providing services to design and develop MMICs, RFICs and microwave and mmWave modules. Services include feasibility studies as well as the design and testing of custom ICs, components and subsystems for international clients in communications, defense and aerospace and at frequencies to 100 GHz. Surface-mount packaging design for volume production at mmWave frequencies is also a specialty. Forefront RF, a recent Cambridge startup, has developed a new approach to mobile phone front-ends, replacing SAW and BAW crystal filters with an adaptive passive cancellation (APC) circuit. It cancels receiver self-interference in a way similar to noise-cancelling headphones. Because one APC circuit can cover many frequency bands, it saves space and reduces complexity.

TIGHT COMMUNITY

The U.K. boasts a particularly tight-knit community of RF and microwave engineers, many of whom regularly attend the bi-annual meeting of the ARMMS RF & Microwave Society, which will make a welcome return in April 2022 after a gap due to COVID-19. Another organization that actively brings engineers together is Cambridge Wireless (CW). In addition to running an annual international conference and a number of focused networking events for the wireless community, CW has an active Special Interest Group for Radio Technology. CW also hosts a 5G testbed, where it runs an accelerator program in partnership with Huawei U.K.

The U.K. Government is actively stimulating technology innovation and manufacturing through Innovate UK and its associated Knowledge Transfer Network and network of Catapults—the most relevant to the microwave sector being the Compound Semiconductor Applications (CSA) Catapult, based in Newport, South Wales. The CSA Catapult supports the U.K.’s RF and microwave industry by providing the following facilities to companies:

• Design studio that helps develop accurate models of the electrical, thermal and electromagnetic behavior of a device, package or module
• Test lab for high bandwidth transmitter and receiver characterization of component and subsystems to 67 GHz
• Packaging lab, applying specialist knowledge to optimize high-frequency packaging
• Evaluation lab that helps companies develop RF and microwave system designs for production.

In December 2021 the UK’s Department for Digital, Culture, Media and Sport (DCMS) announced the 15 projects that had won funding under its Future RAN competition, including many companies named in this article.²

WALES AND WELSH BORDER

The CSA Catapult is part of the Cardiff Compound Semiconductor Cluster, CS Connected,³ which is centered on Cardiff University and encompasses wafer manufacturer IQE and Newport Wafer Fab. CS Connected was the first semiconductor cluster in the U.K. and the first in Europe devoted to compound semiconductors (CS). The experience with other clusters has shown that similar and complementary activities in proximity can build momentum that stimulates further activity. Investment in the area began in 2014 with the Innovation Campus at Cardiff University, continuing with the Compound Semiconductor Institute and the Compound Semiconductor Centre, a joint spin-off with IQE to seed the commercialization of CS technology. This was followed in 2016 with the CSA Catapult and the EPSRC CS Manufacturing Hub; the latter seeks to strengthen the transfer of designs into manufacturing. Cardiff’s Institute of High Frequency and Communication Engineering was initially founded in 1997 and has expertise in nonlinear measurement systems, device characterization and circuit design. A spinout from the Institute, Mesuro, was acquired by Focus Microwaves in 2015, merging their respective load-pull and modeling technologies.

Figure 3 Front (a) and rear (b) of a 256 x 256 single-chassis RF matrix built by ETL Systems.

Just across the Welsh border in Herefordshire is ETL Systems, a manufacturer of RF distribution systems and satcom equipment. In November 2021, ETL received orders of more than $830,000 from a major U.S. Government defense contractor in Colorado, which included its new HAV-80 Havoc RF matrix (see Figure 3), which was configured to 96 x 160 inputs/outputs. The orders also encompassed design and engineering to configure three of ETL’s established Hurricane HUR-10 matrices to operate alongside its L-Band combiners, part of a custom combining matrix. The three 64 × 64 combining matrix systems and one 256 × 256 distributive matrix will be housed within a single 42U chassis, achieving significant savings of rack space and maximizing efficiency. Another well-established Herefordshire microwave enterprise is Teledyne Labtech, one of several Teledyne companies located around the U.K., which specializes in the design, manufacturing and test of RF and microwave printed circuit boards for applications in defense, telecommunications, space and satcom.

SOUTH AND SOUTHWEST

RF and microwave companies to the south of London include Lime Microsystems in Guildford, which specializes in field programmable RF transceivers and software-defined radio (SDR) technology for mobile base stations. Also based in Guildford is Surrey Satellite Technology Ltd. (SSTL)—originally a spinout from the University of Surrey and now a subsidiary of Airbus—which designs and builds small satellites and payloads.

The Isle of Wight is home to broadband amplifier manufacturer Milmega and Vectrawave, which develops MMICs and multi-chip modules for defense, space and communications applications. Further to the west are two waveguide companies: Quasar Microwave Technology in Devon and Flann Microwave in Cornwall. Located in Paignton, Devon, is test manufacturer Spirent Communications. In November 2021, it announced the launch of a simulation test solution for the Galileo High Accuracy Service, a free service providing high accuracy positioning corrections through the Galileo E6-B signal, to an accuracy of less than 20 cm. Bristol is home to a cluster of wireless companies, including Blu Wireless, which uses mmWave frequencies to generate cost-effective carrier-grade wireless networks.

NORTHERN ENGLAND

Another cluster of microwave companies is situated in the north and the northeast of England, in the counties of Yorkshire and Durham. This hub of innovation is largely from the preeminence in microwave research during the late 20th century at the University of Leeds. Leeds professor John David Rhodes established Filtronic in 1977 to develop electronic components for the aviation industry, which he initially made and tested in his home garage and bedroom. The company grew rapidly and, in 2004, was said to be the most successful company ever spun out of a U.K. university.

Figure 4 Morpheus II E-Band transceiver built by Filtronic.

Today, Filtronic has a manufacturing facility in Sedgefield,⁴ where it specializes in E-Band mmWave transceiver modules for high capacity radio links for Xhaul and for high altitude platform systems and LEO satellite links. It also offers a custom hybrid microelectronics manufacturing service. In the past decade, Filtronic has shipped more than 63,000 transceivers, including the most recent Morpheus II (see Figure 4), with 99.9 percent exported outside the U.K. As a result, the company was recently presented with the Queen’s Award for Enterprise for International Trade 2021.⁵ A paper by Filtronic and co-authored by NPL entitled, “Low-Loss 140-175 GHz MMIC-to-Waveguide Transitions and MMIC-to-MMIC Interconnections,” will be presented at EuMW during EuMC.

Many other companies have grown up in the area, mostly with roots connected to either Leeds University or Filtronic. At least four such companies are located in Shipley, Yorkshire, including Radio Design, which manufactures tower mount amplifiers, combiners and interference mitigation filters for sub-6 GHz wireless communications. A second is Slipstream Design, which specializes in designing PAs, transponders and low noise amplifiers with high speed digital electronics and embedded controller software, progressing projects from concept through volume manufacture. Slipstream’s products include radar signal processors for transponder applications. Teledyne Defence & Space, formerly part of Filtronic, specializes in adaptive filters and microwave front-ends for sea, land, air and space. It also manufactures radar warning receiver, radar electronic support measurement and electronic intelligence subsystems, as well as systems capable of handling the dense signal environments found in military operations and highly integrated receiver and broadband jammer subsystems. Finally, Diamond Microwave designs compact, high-power microwave solid-state power amplifiers (SSPAs) using chip and wire GaN technology for applications such as radar, EW, aerospace and communications. The products are optimized for high power-to-volume ratio. Early last year, TMD Technologies Ltd became a shareholder in Diamond Microwave Ltd.

SARAS Technology, in Leeds, manufactures a range of PAs, filters and subsystems to 40 GHz, mainly for defense, aerospace, security and telecom applications. A short distance away, in York, BSC Filters—part of the Dover Corporation—designs and produces active microwave assemblies and modules for phased array radar, EW and commercial applications. These include front-end preselectors, switched filters for antenna front-ends, IF assemblies, digital RF memory front-ends, adaptive filtering and switched multiplexers and filter assemblies for SDR.

THE NORTHEAST

Viper RF is a MMIC designer and manufacturer based in Newton Aycliffe, County Durham. Both of its co-founders, with others on the team, formerly worked for Filtronic Compound Semiconductors prior to its acquisition by RFMD (now Qorvo). Newcastle in northeast England is home to INEX Microtechnology Ltd., which produces nanotechnology and compound semiconductor products. INEX was established in 2014 as a commercial unit of Newcastle University and has since developed collaborative relationships with partners and customers to deliver devices that include power transistors for SSPAs to X-Band from its 6-in. GaN line. INEX has 400 m² of class 1000 cleanroom for front-end processing and 150 m² of class 10,000 cleanroom for back-end processing, packaging, test and characterization. It has been promoted as developing a sovereign GaN technology supply chain to mitigate many of the barriers encountered by existing GaN foundries around the world, due to a combination of IP, competition and export issues.

SCOTLAND

Some years ago, Scotland was home to a cluster of telecoms, defense and semiconductor companies, earning the corridor between Edinburgh and Glasgow the nickname “Silicon Glen.” In recent years, however, many of these facilities have either closed or scaled down.

Trak Microwave, now a Smiths Interconnect brand based in Dundee, designs and manufactures RF and mmWave passive components and subassemblies, including ferrite isolators, circulators, transitions, terminations, loads and couplers for defense and space applications. NXP still operates at the former Motorola/Freescale site in Glasgow but now focuses on automotive applications such as ADAS.

IRELAND

Both Northern Ireland and the Republic of Ireland have a strong history of microwave and, particularly, mmWave technology. Arralis has sites in Belfast in the north and Limerick in the south, as well as Swindon in England. It specializes in mmWave components and modules for the communications, satellite, aerospace and defense markets, specifically at K/Ka-, E- and W-Band. It recently announced that its LE-KaTR-102 Ka-Band transceiver (27 and 30.5 GHz uplink and 17 to 21.2 GHz downlink) had been deployed in the OHB Cosmos CubeSat launched in January 2021. Ferfics, based in Cork, provides design services for front-end RFICs and mmWave semiconductor devices for wireless connectivity applications, including mobile handsets, Wi-Fi, wireless infrastructure, CATV, radar and satcom.

Farran Technology has been developing mmWave products for more than 40 years. Its standard and custom systems and subsystems find applications in test and measurement, radar and imaging, communications, research and development and aerospace. These include 6G products aimed at enabling next-generation devices and systems, as well as facilitating scientific studies of communication channels and new materials for 6G. Analog semiconductor specialist Skyworks has a design center in Cork, as well as another in Bishops Stortford, England.

A VARIED MICROWAVE LANDSCAPE

The U.K.’s microwave industry is no longer shaped by the huge, vertically-integrated defense and telecoms contractors of the past, but their influence can still be detected. Large vendors like Airbus, Leonardo and MBDA have major operations in the U.K. but tend to purchase both components and design services from the vibrant ecosystem of small and medium-sized companies, rather than making them in-house. Space and satcom are currently growing in importance as a market, complementing rather than displacing the more conventional telecoms market.

References

1. H. Duncan, “Staff anger at Bookham’s Caswell GaAs closure,” EE Times, May 27, 2004, Web, www.eetimes.com/staff-anger-at-bookhams-caswell-gaas-closure/.
2. U.K. Department for Digital, Culture, Media & Sport, “Future RAN: Diversifying the 5G Supply Chain Competition Winners,” 8 December 2021, www.gov.uk/guidance/future-ran-diversifying-the-5g-supply-chain-competition-winners.
3. P. Rawlinson, “Connecting the Compound Semiconductor Cluster,” Cardiff University blog, July 20, 2020, Web, blogs.cardiff.ac.uk/innovation/2020/07/20/connecting-the-compound-semiconductor-cluster/.
4. “Filtronic Precision Hybrid Microelectronics Assembly and Test to 90 GHz,” Fabs and Labs, Microwave Journal, June 2020, Vol. 64, No. 6, pp. 98.
5. “Filtronic Wins 2021 Queen’s Award for Enterprise, International Trade,” Microwave Journal, April 29, 2021, Web, www.microwavejournal.com/articles/35913-filtronic-wins-2021-queens-award-for-enterprise-international-trade.