摘要
Because the high frequency operation of a field emission triode amplifier is dictated by the cutoff frequency and not the electron transit time, a high ratio of transconductance, g <sub>m</sub> to the overlapping interelectrode capacitance, C <sub>g</sub> is the desired outcome. Consequently, to achieve high frequency performance of the CNT amplifier array in this study, C <sub>g</sub> was reduced by performing a dual-mask photolithography process to minimize the overlapping gate area, and, the insulating layer's thickness was increased. Moreover, wedge-shaped CNT emitter arrays are employed to increase emission sites, resulting in return higher g <sub>m</sub> . Both dc and ac performance of the amplifier were characterized. The triode amplifier array exhibited a high current of ∼ 0.32 mA (74 mA/cm <sup>2</sup> ), g <sub>m</sub> of ∼ 63 μS and voltage gain of ∼ 18 dB. Frequency response of the triode amplifier up to 20 kHz was also investigated. A theoretical cutoff frequency of > 70 MHz could be achieved with proper shielding of the test setup. © 2006.