Y f I I n I KEY TERMS Multifrequency microwave imaging, permittivity and Conductivity reconstruction, lossy dielectic cylinder, improved Born inversion ABSTRACT Multifrequency Born inversion of the dielectric object is modified to include the lossy dielectric in a slightly lossy background medium. TWO typical numerical examples of a circular and an L-shaped lossy dielectric cylinder are presented with their ranges of validity. By using the improved Born inversion, a permittivity contrast of 1-6 may be reconstructed, but the range of conductivity is rather limited. 0