An elongated hollow microporous fiber comprises an inner wall surface defining an interior fiber lumen, an outer wall surface, and a microporous fiber wall therebetween, the fiber wall having one or more continuous, cohesive, elongated filaments embedded in the fiber and extending lengthwise of the elongated fiber along substantially the full length of the fiber. An antenna device 31 is formed on an antenna substrate 30 installed upright in an antenna base 20. The silicon nitride layer and oxide layers on opposite sides thereof insulate edges of a polysilicon emitter from the underlying transistor regions, minimizing the parasitic capacitance between the NPN transistor’s emitter and achieving a high frequency response.