Forefront RF To Unveil Industry's First Commercial Low-Band Tunable Duplexer At Mobile World Congress 2026

Foretune technology replaces fixed SAW/BAW filters with a dynamically configurable architecture spanning 612–960 MHz

At Mobile World Congress (MWC) 2026. Forefront RF, a Cambridge-based fabless semiconductor scale-up, has launched, what it believes to be the industry’s first commercially available tunable duplexer module, the FFM51010, implemented without SAW or BAW acoustic filtering. Enabled by its proprietary adaptive passive cancellation technology, branded Foretune, the module represents a paradigm shift in RF front-end design for cellular-enabled smartwatches, smartphones and other connected devices. The company will be giving live demonstrations of the FFM51010 at Booth A9.16 in the UK Pavilion, Hall 7, including detailed technical performance data and validation results.

Today’s mobile devices rely on banks of duplexers, filters and switches, each restricted to a specific frequency band. As operators make additional spectrum available to meet growing data usage, manufacturers must support an increasingly fragmented global RF landscape. The result has been rising RF front-end complexity, larger component counts, regional differences in RF frequency bands, and increasing pressure in compact, space-constrained devices.

The FFM51010 addresses this challenge using Adaptive Passive Cancellation. Similar in principle to noise-cancelling headphones, which eliminate unwanted background sound by generating an opposing signal, the system creates an inverted replica of transmitter leakage and cancels it at the receiver input in real time. By actively suppressing this self-interference at radio frequency, the module replaces multiple fixed, band-specific filters with a single configurable solution while maintaining the linearity and stability required for increasingly complex multi-band devices.

“Despite longstanding research into reconfigurable RF systems, delivering a practical, high-linearity tunable duplexer suitable for high-volume cellular deployment has remained a significant technical challenge,” said Ronald Wilting, CEO of Forefront RF. “With Foretune, we are introducing configurability into one of the last rigid hardware blocks of the mobile radio.”

Key technical characteristics include:

• Receive frequency range: 612–960 MHz
• Transmit frequency range: 663–915 MHz
• Supported channel bandwidth: 1.4–20 MHz (higher bandwidth under development)
• Tunable duplex spacing: –46 MHz to +55 MHz
• Supported bands: 5, 8, 12, 13, 14, 17, 18, 19, 20, 26, 28, 71, 85, 105
• Integrated multi-mode power amplifier
• Integrated low-noise amplifier
• Integrated antenna-port bi-directional RF coupler
• No external duplexers required
• Single MIPI RFFE v3.0 interface
• LGA package: 6.0 × 4.5 × 0.75 mm

The device supports both Average Power Tracking (APT) and Envelope Tracking (ET) architectures and is targeted at 4G LTE, 5G NR and 5G RedCap user equipment, particularly single-antenna systems.

This first product release focuses on low-band spectrum. Future product generations are planned to extend the Foretune architecture into mid-band and high-band frequencies.