Electron-cyclotron maser emission is investigated. in the regime where
wave growth in the electrostatic Bernstein modes dominates (omega(p)/
Omega(e) > 1.5). A semirelativistic growth rate is derived assuming th
at the wave dispersion is dominated by a cool background electron dist
ribution and the instability is driven by a low-density I-lot loss-con
e-like electron distribution. The properties of Bernstein wave growth
are most strongly dependent on the relative temperatures of the hot an
d cool electron distributions. For T-hot/T-cool greater than or simila
r to 10, the fastest growing Bernstein waves are produced. at frequenc
ies just below each cyclotron harmonic in Bernstein modes lying below
the upper-hybrid frequency. For T-hot/T-cool less than or similar to 1
0; additional Bernstein modes above the upper-hybrid frequency are exc
ited, with wave frequencies in each excited mode lying significantly a
bove tile corresponding cyclotron harmonic. The dependence of Bernstei
n wave growth on the relative hot and cool electron number densities a
nd emission angle is also discussed.