A GaAs Power MESFET Operating at 3.3V Drain Voltage for Digital Hand-Held Phone

A GaAs power metal semiconductor field effect transistor (MESFET) operating at a voltage as low as 3.3V has been developed with the best performance for digital hand-held phone. The device has been fabricated on an epitaxial layer with a low-high doped structure grown by molecular beam epitaxy. The MESFET, fabricated using 0.8 μm design rule, showed a maximum drain current density of 330 mA/mm at V_gs = 0.5V and a gate-to-drain breakdown voltage of 28 V. The MESFET tested at a 3.3 V drain bias and a 900 MHz operation frequency displayed an output power of 32.5-dBm and a power added efficiency of 68%. The associate power gain at 20 dBm input power and the linear gain were 12.5dB and 16.5dB, respectively. Two tone testing measured at 900.00MHz and 900.03MHz showed that a third-order intercept point is 49.5 dBm. The power MESFET developed in this work is expected to be useful as a power amplifying device for digital hand-held phone because the high linear gain can deliver a high power added efficiency in the linear operation region of output power and the high third-order intercept point can reduce the third-order intermodulation.