A microwave module is described. The microwave module includes a base bracket, a window plate and a lid. The base bracket is configured to contain a photoconductive switch, a radio-frequency transformer and dielectric oil. The window plate, which is transparent to optical light, covers a first portion of the base bracket in which the photoconductive switch is located. The window plate is sealed to the base bracket. The lid, which includes a cutout to allow the radio-frequency transformer to pass through the lid, covers a second portion of the base bracket in which the radio-frequency transformer is located. The window plate is sealed to the base bracket, and the lid is sealed to the window plate, the base bracket and the radio-frequency transformer to contain the dielectric oil within the microwave module.