Low–frequency circuit theory of the double–base diode

The double-base diode is a single-junction semiconductor triode. When an electric potential is applied between the two ohmic contacts, a negative-resistance is obtained between the junction and one of the ohmic contacts. This negative resistance is bounded by two positive-resistance regions, one of considerably high magnitude which corresponds to the cut-off state and one of very low magnitude which corresponds to a saturating condition. The magnitude of the negative resistance is related to the ratio of majority-to-minority carrier mobilities. Small-signal low-frequency equivalent circuits are developed to approximate the double-base diode in each of the operating regions of the negative-resistance characteristic and equations for current and voltage amplification, input and output resistance and power gain are developed. The important circuit parameters are related to the physical constants of the device.