Array and element design for complementary large-volume power deposition patterns in microwave heating

In interstitial hyperthermia cancer treatment and other invasive microwave heating applications, arrays of implanted coaxial dipoles have been used to provide regional heating of human tissue and a variety of materials. Phase modulation of the array-element excitations has been proposed as a means of obtaining uniform, time-average power densities. In the paper an insulated monopole at its second resonance is described as an alternative to the large-diameter coaxial dipole, and a pair of complementary excitations is proposed as a means of obtaining uniform, time-average power density. The array configuration considered consists of four monopoles inserted into a homogeneous medium having a high, complex permittivity. The cases of bare metal and insulated monopoles are analyzed using the method of moments and the theory of insulated antennas in matter.