An applicator and method for application of electromagnetic energy to an area of tissue is described. The applicator includes a visually-transparent, high-dielectric interfacing assembly which has a conformable tissue-engaging surface and an opposed antenna-engaging surface. At least one balanced, circularly-polarized antenna is disposed in a plane substantially parallel and adjacent to the antenna-engaging surface. The interfacing assembly and at least one antenna are substantially transparent to enable visual viewing of the area of tissue. This enables monitoring of the tissue for adverse treatment effects while electromagnetic energy is being applied to the at least one antenna and radiated into the tissue.