Forefront RF Gets £1.5m to Develop Multi-Band Frequency Agile RF Chip

Article By : Nitin Dahad

Forefront RF plans to build out its development team and prove the technology for its frequency agile tunable RF front-end chip addressing multiple mobile frequency bands.

A Cambridge, UK-based fabless semiconductor company that has developed a frequency agile, tunable RF front-end chip addressing multiple mobile handset frequency bands has announced £1.5 million funding to further develop its chip.

Forefront RF was established in 2020 based on research by Leo Laughlin at the University of Bristol. Laughlin and his co-founder Julian Hildersley met through mutual contacts last year and set up the company in Cambridge, where he said there is a strong talent pool of RF expertise. The company expects to double the team to 10 people by the end of the year, looking to recruit engineers with experience in RF system architecture, software algorithms, and physical design and layout.

Forefront RF Julian Hildersley and Leo Laughlin
Co-founders of Forefront RF at their office in Cambridge, UK. Julian Hildersley (left) and Leo Laughlin (right) set up the company in 2020 on the back of nine years’ research by Laughlin at the University of Bristol. (Source: Forefront RF)

So what is the problem that Forefront RF is solving? In an interview with EE Times Europe, Laughlin explained that with spectrum fragmentation around the world and with over 70 different frequency bands, it is difficult for manufacturers to make a phone that covers all world regions. “You need different sets of RF components for each region,” he said. “The growth in mobile networks driven by the ever-increasing demand for data means that available frequency bands vary from region to region and, using today’s technology, has driven the need for region-specific smartphone variants each including multiple RF components. The space consumed within each smartphone adds cost and leads to inefficiencies in the supply chain.”

Hildersley added, “What we have developed is a tunable RF technology using adaptive passive cancellation (APC) that can replace the multiple components needed and make the single device frequency agile, through software. Hence, this reduces the number of variants manufacturers have to make for different markets.”

The chip developed by Forefront RF uses its adaptive passive cancellation (APC) technology, similar to that used in noise-cancelling headphones. Forefront RF’s APC chip replaces the banks of RF filters and switches with a low cost, tunable RF circuit. The component uses embedded software to maintain the accuracy of unique passive self-interference cancellation circuits. This enables a smartphone’s receiver to “hear” the weakest signals while transmitting at full power.

Forefront RF APC explainer_correct
The current problem is self-interference (left), where the wireless signal being transmitted is much more powerful than the incoming signal, resulting in self-interference at the receiver which drowns out the signal you want to receive. The current solution (middle) is to use SAW/BAW crystal filters, but separate crystals are requited for each frequency band. Forefront RF’s solution (right), replaces the crystal filters with an adaptive passive cancellation (APC) circuit, which cancels out self-interference in a similar way to noise cancelling headphones. One APC circuit can cover many frequency bands. (Source: Forefront RF)

Laughlin said there is nine years of research behind the chip. He has published many papers and presented at conferences areas covering antennas, radio frequency self-interference cancellation, tunable and reconfigurable RF technologies, and more efficient use of spectrum.

We asked if the research behind the APC technology has been around for a while, why has it not been done yet? He responded, “Yes, the concept of cancellation is not new. The trick is in implementing RF circuits incorporate cancellation in the analog domain at high frequencies while enabling other features necessary in the phone, such as power [consumption]. The breakthrough is in coming up with the method of maintaining accuracy in that signal cancellation process.”

Forefront RF front end chip
Forefront RF said it wants to be a components business, manufacturing its frequency agile RF chip for mobile handsets. (Source: Forefront RF)

Co-founder Hildersley was previously with TTPCom and Nujira. At TTPCom, he formed its silicon IP licensing business and also led the integration of TTPCom’s silicon IP and protocol software into Motorola’s mobile devices; at Nujira, which was acquired by Qualcomm, he led the product team where he recruited the founding members of the chip development team.

Asked what their immediate plans are, Hildersley said, “We are now aiming to prove the technology.” As regards how they intend to make money, he said, “We are quite clear we want to be a component business. We want to be a fabless business and provide components through contracted out manufacturing, which is the norm today.”

The £1.5 million investment comes from a syndicate led by Bristol-based Science Creates Ventures and includes Foresight Williams Technology, BGF, and The Cambridge Angels. One of the investors and non-executive chairman of the company is Phil O’Donovan, who was a managing director and co-founder of Bluetooth chip market leader CSR. This first round of investment will enable Forefront RF to recruit the team they need to accelerate the launch of its products.

This article was originally published on EE Times Europe.

Nitin Dahad is a correspondent for EE Times, EE Times Europe and also Editor-in-Chief of embedded.com. With 35 years in the electronics industry, he’s had many different roles: from engineer to journalist, and from entrepreneur to startup mentor and government advisor. He was part of the startup team that launched 32-bit microprocessor company ARC International in the US in the late 1990s and took it public, and co-founder of The Chilli, which influenced much of the tech startup scene in the early 2000s. He’s also worked with many of the big names—including National Semiconductor, GEC Plessey Semiconductors, Dialog Semiconductor and Marconi Instruments.

 

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