Balanced Near-Field Applicator for Controlled Microwave Tissue Exposure

We present a near-field applicator for monitoring microwave exposure of tissue samples on an inverted microscope also used for optical studies of these samples. The applicator operates at X-band (8-12 GHz) and employs low-cost fabrication technology such as printed circuit board (PCB) and 3D printing. Using a symmetrical dual-horn antenna, an almost-identical near-field distribution can be achieved on both ends of the applicator. With a diode detector array observation board on the control end, we can estimate and monitor the power at the tissue surface under exposure by symmetry. Measurement results of the initial prototype show agreement with simulations within 0.9 dB.