MICROWAVE DIODE RESEARCH.
Interim rept. no. 1, 10 Jun-9 Sep 65,
WESTERN ELECTRIC CO INC NEW YORK
Pagination or Media Count:
Chapter 1 describes room-temperature microwave measurements that have been made to characterize an epitaxial silicon p-n-n avalanche diode in continuous operation. The diode is believed to have an avalanche somewhat distributed 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 diode exhibits a negative conductance over a band in excess of an octave about a center frequency in the 5- to 10-Gc range. However, a large current-dependent susceptive component places constraint on the utilization of this negative-conductance band. The noise power output in the negative-conductance band was functionally related to the bias current however, the noise figure of a high-gain amplifier was only moderately influenced because of the diodes increased negative conductance with bias current. The typical noise figure of a 10-db amplifier was 45 db. In Chapter 2 a one-dimensional, small-signal analysis of the space-charge region of a p-n junction in which avalanche occurs uniformly is presented. The impedance is found to have a negative real part. The impedance is well represented by a parallel connection of the depletion layer capacitance, an inductance, and a negative resistance. The admittance of the latter two is proportional to the bias current. The magnitude of the negative Q is below ten. The negative resistance is due to an intrinsic instability in the avalanching electron hole plasma. A discussion of the instability and a traveling-wave-tube type of amplification is given.
- Electrical and Electronic Equipment
- Solid State Physics