A shielding assembly and method for use with an electromagnetic field generating source. The assembly includes an outer housing that includes a conductive material. The outer housing defines a chamber in which the field generating source is located. A polymeric inner body substantially fills the chamber. The inner body is spaced from and circumscribes the field generating source. The field generating source may be the resonant oscillator of a microwave transceiver circuit and the inner body may advantageously include between 2-10%, by weight, of a semiconductive filler such as carbon or graphite. A printed circuit board may be attached to the outer housing to define the chamber together with the outer housing. The inner body may be secured within the chamber by compressive engagement between the printed circuit board and outer housing. Spacing elements are used to provide a clearance gap between the printed circuit board and the inner body.