We calculated the oscillation power and total linewidth of the diode-l
aser-pumped Rb-87 maser with spatial variations of the pumping rate an
d the radiative microwave field in the resonance cell. It is found tha
t the maximum oscillation power P(max) corresponding to the optimum pu
mping rate GAMMA(opt) does not increase monotonically with the atomic
density no and that the short-term frequency stability of the maser co
rresponding to P(max) is about a factor of three better than that curr
ently obtained with a lamp-pumped Rb-87 maser. Some results are in fai
r agreement with our previous experiments. We also examined the variat
ion of the oscillation powers vs light intensity in an average mode fo
r three laser-pumping schemes with different frequencies and polarizat
ions of the diode lasers.