  Field Emitting Arrays (FEAs) are a promising alternative to the conventional
cathodes in different vacuum electronic devices such as traveling wave tubes,
electron accelerators and etc. Electrical gating and modulation capabilities,
together with the ability to produce stable and homogeneous electron beam in
high electric field environment are the key requirements for their practical
application. Due to relatively high gate capacitance, fast controlling of FEA
emission is difficult. In order to achieve sub-nanosecond, electrically
controlled, FEA based electron emission a special pulsed gate driver was
developed. Bipolar high voltage (HV)pulses are used to rapidly inject and
remove charge form FEA gate electrode controlling quickly electron extraction
gate voltage. Short electron emission pulses (<600 ps FWHM) were observed in
low and high gradient (up to 12 MV/m) environment. First attempts were made to
combine FEA based electron emission with radio frequency acceleration
structures (1.5 GHz) using pulsed preacceleration. The gate driver design
together with low inductance FEA chip contact system is described. The results
obtained in low and high gradient experimental setups are presented and
discussed.
