An apparatus includes active layers, and a first high resistive layer disposed between the active layers. The apparatus further includes second and third high resistive layers disposed on respective surfaces of the active layers, the second and third high resistive layers including first and second strip conductors, respectively, the first strip conductors being connected at an end by a first connecting conductor, the second strip conductors being connected at an end by a second connecting conductor, and the first connecting conductor being disposed perpendicularly to the second connecting conductor. The apparatus further includes first contact pads disposed on respective ends of the first connecting conductor, and second contact pads disposed on respective ends of the second connecting conductor. The apparatus further includes matching layers disposed on respective surfaces of the second and third high resistive layers.