OREANDA-NEWS. June 06, 2011. Fujitsu Laboratories Ltd. today announced that it has successfully developed the world's first transmitter/receiver (T/R) module using gallium-nitride (GaN)(1)high electron mobility transistor (HEMT)(2) technology that features an output of 10 W and that operates in a wide bandwidth range of C-band, X-band, and Ku-band (C-Ku band)(3) radio frequencies over 6-18 GHz. By combining the world's best performing GaN power amplifier (PA) developed last year with the newly developed GaN low-noise amplifier (LNA), the researchers achieved a compact T/R module that generates a high-output.

This technology makes possible the integration of multiple types of communications equipment—each currently operated at a different frequency range—into a single module, making for the development of smaller, lighter radar equipment and wireless communication systems.

Details of this technology will be presented at the IEEE MTT International Microwave Symposium (IMS 2011) held in Baltimore, Maryland, starting June 5.
GaN HEMT

Gallium-nitride (GaN) is used as a blue-LED in traffic signal lights, and compared to the conventional semiconductor materials of silicon (Si) and gallium-arsenide (GaAs), it features a high saturation carrier velocity and relative resistance to the breakdown caused by voltage. Given these characteristics, GaN HEMTs—or transistors that use GaN—show promise for high-output and exceptionally efficient operations.
Background

In line with the advance of a network-based society, radio wave demand in a variety of wireless systems is expected to increase even further. For example, aircraft radar typically switches between the C-band, which can detect distant objects and works well in rain, and the X- and Ku-bands which are able to measure physical objects with high-precision.

Currently, this demand for multiple frequency ranges requires different communications equipment each suited to their respective frequency band. However, a single T/R module capable of covering the entire C-Ku band range would meet a variety of needs, allowing systems to become more compact.