Impedance and noise characteristics of a microwave amplifier using avalanche diodes

Room Temperature microwave measurements have been made using an epitaxial silicon p n n + avalanche diode in continuous operation. The diode is believed to have a somewhat distributed avalanche throughout the depletion layer as contrasted to the Read model in which the avalanche is confined to a narrow zone within the depletion layer. The difference between the models, for the small signal case, appears to be distinguishable from the diode´s microwave impedance characteristics.