+44 (0)24 7671 8970
More publications     •     Advertise with us     •     Contact us
*/
News Article

Speeding up future electronics with graphene mixer

The mixer provides new opportunities as it enables compact circuit technology, potential to reach high frequencies and integration with silicon technology

Researchers at Chalmers say they have, for the first time, demonstrated a novel sub-harmonic graphene FET mixer at microwave frequencies.

​A mixer is a key building block in all electronic systems. An electronic mixer is a device that combines two or more electronic signals into one or two composite output signals. Future applications at THz frequencies such as radar systems for security and safety, radio astronomy, process monitoring and environmental monitoring will require large arrays of mixers for high-resolution imaging and high-speed data acquisition. Such mixer arrays or multi-pixel receivers need new type of devices that are not only sensitive but also power-efficient and compact.

 

 

Schematic picture of a subharmonic graphene-FET mixer. The LO and RF signals are fed to the gate and drain terminals, respectively, and the IF signal is extracted from the drain terminal

The ability in graphene to switch between hole or electron carrier transport via the field effect enables a unique niche for graphene for RF IC applications. Thanks to this symmetrical electrical characteristic, the researchers at Chalmers have managed to build the G-FET sub-harmonic resistive mixer using only one transistor.

Hence, no extra feeding circuits are required, which makes the mixer circuit more compact as opposed to conventional mixers. As a consequence, the new type of mixer requires less wafer area when constructed and can open up for advanced sensor arrays, for example for imaging at millimetre waves and even sub millimetre waves as G-FET technology progress.

“The performance of the mixer can be improved by further optimising the circuit, as well as fabricating a G-FET device with a higher on-off current ratio”, says Jan Stake, professor of the research team. “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.”

 

 

In addition to enabling compact circuits, the G-FET provides potential to reach high frequencies thanks to the high velocity in graphene, and the fact that a sub-harmonic mixer only requires half the local oscillator (LO) frequency compared to a fundamental mixer. This property is attractive especially at high frequencies (THz) where there is a lack of sources providing sufficient LO-power.

Moreover, the G-FET can be integrated with silicon technology. For example, it is CMOS compatible (Complementary Metal Oxide Semiconductor) and among other things it can be used in CMOS electronics for backend processing on a single chip.

Graphene, which was first demonstrated in 2004, has rapidly gone from curiosity‐driven to applied research.

The work is published in the paper, "A Subharmonic Graphene FET Mixer" , by O. Habibpour et al  in IEEE Electron Device Letters, 33(1), 71 -73, January 2012. 10.1109/LED.2011.2170655

The Swedish Foundation of Strategic Research supported this work.
Connecting the Compound Semiconductor Industry

The 13th CS International conference builds on the strengths of its predecessors, with around 40 leaders from industry and academia delivering presentations that fall within five key themes: Ultrafast Communication; Making Headway with the MicroLED; Taking the Power from Silicon, New Vectors for the VCSEL, and Ultra-wide Bandgap Devices.

Delegates attending these sessions will gain insight into device technology, find out about the current status and the roadmap for the compound semiconductor industry, and discover the latest advances in tools and processes that will drive up fab yields and throughputs.

To discover our sponsorship and exhibition opportunities, contact us at:

Email: info@csinternational.net
Phone: +44 (0)24 7671 8970

To register your place as a delegate, visit: https://csinternational.net/register

Register
×
Search the news archive

To close this popup you can press escape or click the close icon.
×
Logo
×
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.


Please subscribe me to:

 

You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in: