Abstract
Preliminary results of an analysis of data with high spatial resolution and high temporal resolution are presented for
the event of May 14, 1993. Observations were made with the three-channel 10 cm band radiotelescope of the Beijing
Astronomical Observatory (BAO) and simultaneously with the Nobeyama Radioheliograph (NoRH) at 17 GHz. The
results show that the microwave spike emission was produced in a region with lower brightness temperature, high
degree of polarization, high and compact magnetic field and small dimension. The microwave spike emission has a
frequency drift rate of more than 30 GHz/s and in X-mode. These results are consistent with the mechanism of
electron cyclotron maser (ECM) instability.