The effects of cathode contacts on the noise factor of transferred electron amplifiers

To a first approximation the noise factor of small-signal negative-resistance transferred-electron amplifiers is evaluated using the impedance-field method of noise calculation. The noise is considered to arise solely from thermal sources and the d.c. carrier velocity (or d.c. electric field intensity) is considered uniform throughout the diode. To these approximations a general expression can be written for the amplifier noise factor. The effects of different a.c. cathode boundary conditions can then be demonstrated.