  The energy and spectral shape of radio bursts may help us understand the
generation mechanism of solar eruptions, including solar flares, CMEs, eruptive
filaments, and various scales of jets. The different kinds of flares may have
different characteristics of energy and spectral distribution. In this work, we
selected 10 mostly confined flare events during October 2014 to investigate
their overall spectral behavior and the energy emitted in microwaves by using
radio observations from microwaves to interplanetary radio waves, and X-ray
observations of GOES, RHESSI, and Fermi/GBM. We found that: All the confined
flare events were associated with a microwave continuum burst extending to
frequencies of 9.4 - 15.4 GHz, and the peak frequencies of all confined flare
events are higher than 4.995 GHz and lower than or equal to 17 GHz. The median
value is around 9 GHz. The microwave burst energy (or fluence) as well as the
peak frequency are found to provide useful criteria to estimate the power of
solar flares. The observations imply that the magnetic field in confined flares
tends to be stronger than that in 412 flares studied by Nita et al. 2004. All
10 events studied did not produce detectable hard X-rays with energies above
300 keV indicating the lack of efficient acceleration of electrons to high
energies in the confined flares.
