26 May 2011

Mitsubishi's GaN HEMT PA for C-band satellites hits record PAE of 67%

Tokyo-based Mitsubishi Electric Corp has developed a gallium nitride high-electron-mobility transistor (GaN HEMT) power amplifier (PA) for C-band satellites with what is claimed to be record power-added efficiency (PAE) of 67% (up by more than seven percentage points compared with conventional amplifiers).

The amplifier is expected to lead to smaller and lighter transmitter devices to help microwave communication satellites save power. Mitsubishi Electric will present the breakthrough at the International Microwave Symposium for 2011 (IMS 2011) in Baltimore, MD, USA (5–10 June).

Mitsubishi Electric says that, as more satellites complete their operational lifespan, demand is increasing for new microwave communication satellites with smaller, lighter and more efficient satellite transponders. Conventional transponder devices use traveling wave tube amplifiers (TWTAs) because solid-state power amplifiers with GaAs HEMTs, which lack sufficient output power and efficiency, require an additional amplifier to attain high output power. More efficient GaN HEMT amplifiers with high output power, high-field electron velocity and high breakdown fields are expected to replace TWTAs in communication satellites.

The new amplifier’s PAE of 67% is enabled by what Mitsubishi Electric claims is the world’s first harmonic tuning circuit — consisting of a MIM (metal–insulator–metal) capacitor and a spiral inductor — placed in front of each GaN HEMT cell on the substrate. The PAE was improved through the second-harmonic impedance of the GaN HEMT using a highly accurate input control.

The internally impedance-matched GaN HEMT amplifier has a high output power of 107W (50.3dBm) but a small package size of 17.4mm x 24.0mm x 4.3mm and a light weight of 7.1g.

Going forward, Mitsubishi Electric intends to further enhance the efficiency and power performance of its GaN HEMT amplifiers for satellites and wireless communication systems.

Tags: Mitsubishi GaN HEMT

Visit: www.MitsubishiElectric.com/semiconductors

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