Theory and measurement of back bias voltage in IMPATT diodes

A new analysis of back bias voltage derivation shows it to require that the Read (1958) equation's derivation be carried to one order of approximation beyond that necessary to obtain the quasi-static result, and to need a new expression term for the back bias voltage which changes its sign to positive under conditions in which the older analyses indicate a negative back bias. In the experimental setup presently employed to test this new analysis, measurements were made on a diode which is designed to operate at K-band, near 20 GHz. At frequencies considerably below the range at which measurements were made, a strong negative bias voltage is caused by the saturation current.