At EuMW 2026, everything RF met Aamir Sheikh, Director of Engineering at Focus Microwaves, an MPI company, who demonstrated the company’s Rapid VT Active Load Pull platform and a new harmonic modelling capability developed in collaboration with Cardiff University. European Microwave Week (EuMW) 2026, held from 4-9 October at ExCeL London, is Europe’s premier event for the RF, microwave, mmWave, and radar industry, bringing together the companies and technologies shaping the future of high-frequency engineering.
At its booth, Focus Microwaves showcased how rapid active load-pull measurements and behavioural modelling can help engineers characterize RF power transistors and optimize power amplifier designs more efficiently. The demonstration combined the company’s Rapid VT Active Load Pull platform with a Keysight Technologies PXI-based test setup, along with Focus Microwaves test hardware and amplifiers, and used a 6 W transistor to generate behavioural models spanning both the fundamental and second-harmonic frequencies.
Rapid VT Active Load Pull Platform
The Rapid VT Active Load Pull platform is Focus Microwaves’ wideband active load-pull solution for RF power device characterization and amplifier design. Active load-pull testing enables engineers to present controlled impedance conditions to a device under test and measure its performance under operating conditions that more closely reflect real-world use. By varying the load impedance seen by a transistor, engineers can determine the conditions that deliver the highest output power, efficiency, gain, and linearity, information that is essential for the development of RF power amplifiers and RF front-end components. The platform combines active load-pull measurements with S-parameter and modulated signal characterization on a common test architecture, supporting applications from device characterization and modelling to design verification and production testing.
Unlike passive load-pull systems, active load-pull technology extends the achievable impedance range by injecting controlled RF energy back into the device under test. This allows engineers to present a wider range of load conditions at the transistor reference plane and evaluate performance beyond the limits imposed by passive tuners and fixture losses. Built around a PXI-based measurement architecture, the Rapid VT platform supports modern wideband communication signals and enables both load-pull and S-parameter measurements on the same test bench, helping simplify device characterization and accelerate development workflows.
During the demonstration, Sheikh showed how the platform performs extremely fast measurements, with each load-pull measurement taking approximately 0.1 to 0.2 seconds. The system can complete a 30 dB power sweep within an hour, enabling the rapid collection of large volumes of device characterization data.
Harmonic Modelling
A key highlight of the demonstration was a new modelling capability developed in collaboration with Cardiff University. The technique uses rapid active load-pull measurements collected across multiple harmonics to generate a behavioural model of the device under test. Unlike traditional approaches that focus primarily on the fundamental frequency, the Cardiff Model captures transistor behaviour at both the fundamental and second-harmonic frequencies, providing a more complete representation of amplifier performance.
The measured data can be imported into the Cardiff modelling software, which generates a behavioural model that can then be exported to simulation environments including Keysight Technologies’ ADS (Advanced Design System) and other RF design tools. This enables engineers to move directly from measurement to simulation, reducing development time while maintaining strong correlation between measured and simulated results.
During the live demonstration, Sheikh compared measured load-pull data with model predictions. The results showed close agreement between the measured and simulated power and efficiency contours at the fundamental frequency. More notably, the same level of correlation was achieved at the second harmonic, where the demonstrated VSWR sweep exhibited less than 0.1 dB difference in output power and less than 1% difference in efficiency between the measurement data and the behavioural model. This level of harmonic accuracy provides amplifier designers with deeper insight into device behaviour and enables more effective optimization of amplifier performance.
At the EuMW 2026 exhibition floor, Focus Microwaves highlighted how advances in active load-pull technology are enabling faster and more accurate RF power amplifier development. By combining rapid impedance tuning, high-speed measurement acquisition, and harmonic behavioural modelling, the company’s Rapid VT Active Load Pull platform provides engineers with a workflow that bridges device characterization and simulation-driven design. The addition of the Cardiff Model extends this capability beyond conventional load-pull measurements, helping designers better understand and exploit transistor performance across both fundamental and harmonic frequencies.
European Microwave Week 2026 showcased the latest developments in wireless communications, aerospace and defense, radar, satellite technology, semiconductors, antennas, and test and measurement solutions. From advanced RF characterization technologies to next-generation design and simulation tools, the event highlighted many of the innovations shaping the future of high-frequency engineering. To discover more technologies, product launches, and demonstrations from across the exhibition floor, click here to view everything RF’s complete EuMW 2026 coverage.
Click here to learn more about Focus Microwaves and its RF solutions.