Graphene electronic mixer runs at microwave frequencies

Swedish researchers have created a novel graphene electronic mixer that can operate at microwave frequencies.

Such high frequencies could open up applications in radar systems for security and safety; radio astronomy; and process and environmental monitoring.

In electronics, mixers are devices that combine two or more electronic signals into one or two composite output signals and are key building blocks in all electronic systems.

Real-world applications such as radar require large arrays of mixers for high-resolution imaging and high-speed data acquisition. There is also a need for mixer arrays or multi-pixel receivers that are not only sensitive but also power efficient and compact.

Researchers at Chalmers University made use of graphene’s ability to switch between hole or electron carrier transport via the field effect.

They managed to build graphene based field-effect transistor (G-FET) subharmonic resistive mixer using only one transistor.

The new type of mixer requires less wafer area when constructed and is applicable to advanced sensor arrays, for example, imaging at millimetre waves and even sub-millimetre waves.

Project lead Prof Jan Stake of Chalmers said: ‘Using a G‐FET in this new topology enables us to extend its operation to higher frequencies, thereby exploiting the exceptional properties of graphene. This paves the way for future technologies operating at extremely high frequencies.’