Avalanche breakdown voltage V
B, space-charge width at breakdown W
B, and

index

of exponentially retrograded silicon hyperabrupt p
+-n junctions have been calculated for various impurity distributions. Empirical relations are obtained expressing W
B, V
B, and the maximum value of

in terms of impurity profile parameters of the retrograded region. Applications of these relations in the design of hyperabrupt varactors is indicated.