Patent ID: 6957108

Claim:
A microwave hyperthermia antenna applicator for heating local regions of tissue within a living body, comprising: (a) a hollow central conductor having a length and sufficient in size to permit the insertion of radiation therapy sources; (b) an outer conductor having a length and positioned substantially coaxially with the central conductor along a portion of the length of the hollow central conductor to form a coaxial section of the applicator having impedance lower than the impedance of a coaxial source cable that would connect the applicator to a source of microwave power, the inner conductor extending beyond the outer conductor to form a microwave radiating section having a higher impedance than the coaxial section; and (c) wherein the length of the coaxial section is approximately equal to an integral number of half wavelengths of microwave energy of a frequency expected to be applied to the applicator by the coaxial source cable, such hat the impedance matching for the connection point of the microwave source cable to the applicator is substantially impedance matched for efficient transfer of microwave power from the source cable to the tissue surrounding the microwave radiating section.