Gapped resonant microwave apparatus for producing hyperthermia therapy of tumors

An apparatus for treating biological tissue by microwave induced hyperthermia comprising:

• (a) a primary resonant source of microwave energy,
• (b) a resonant microwave circuit including a pair of resonant waveguide means coupled to said primary resonant source to form a resonant loop having a gap between spaced ends of said waveguide means, and the biological tissue to be treated comprising the dielectric loading adapted to be located within said gap, and
• (c) means interposed between said dielectric loading and each of the spaced ends of waveguide means interfacing said waveguide means and said tissue for optimally coupling said microwave energy of said microwave circuit in opposite directions, said coupling means including
• (1) a wedge-shaped dielectric medium in contact with a medium having an intrinsic impedance and
• (2) a dielectric fluid-filled nonmetallic enclosure in contact with both said wedge-shaped dielectric medium and a medium of higher intrinsic impedance.