Noise minimization in photodiode-driven distributed amplifiers

Input-reduced noise current density of a distributed amplifier excited by a photodiode is minimised. It has been found that for low noise the admittance of the transmission line between the amplifier and the pin photodiode has to be small. To prove this statement we have obtained an analytical formula for the input-reduced noise current density of the simplest possible distributed amplifier. Effect of the diode capacitance and resistance on the input-reduced noise as a function of characterstic impedance of the input line is studied. Then our statement is verified numerically for the case of a more complicated distributed amplifier.