P ∝ t^− 1 at 20 ns–100 ns and P ∝ t^− 1/2 at 100 ns–2000 ns.

Damage power declines as pulse number increases when pulse number is less than 100.

Gate metal strip and its surroundings are vulnerable parts of PHEMT.

Vulnerable parts of BJT are input terminal of base electrode and Si materials below.

For BJT, the longer the pulse width is, the larger the damage area is.