Angled dual compact hyperthermic applicators

The compact array described here uses two microstrip half-wave radiating elements, driven in phase, polarised for complete field reinforcement and having an oblique flare-angle between the faces, the reduction of which increases field concentration. An approximate analysis of the configuration for various applicator sizes, frequencies of operation and flare-angles enables field plots to be readily computed for realistic, homogeneous, tissue electrical constants. Measurements at 900 and 918 MHz using uniform and cylindrical tissue phantoms, respectively, and different methods of thermometry produced results in accord with theory. It is concluded that the dual angled compact applicator is an effective way of increasing the depth of localised heating and is less bulky than its waveguide counterpart.