Apparatus and method for transmitting electrical power and broadband RF communications signals through a dielectric

An interface device permits installation of a video system by direction broadband RF signals from an outdoors transmission line to an indoors receiver and by providing electrical power from the receiver to the transmission line for the antenna electronics without requiring a hole for passage of a coaxial cable. Power transmission circuitry includes a first inductor mounted adjacent the first side of a window and connected to the first transmission line to receive DC electrical power therefrom. A square wave drive signal is applied to switch apparatus that converts the DC power received by the inductor into time-varying electrical signals that produce a time-varying magnetic field. A second inductor that is part of a resonant circuit mounted adjacent the dielectric layer opposite the first inductor receives the transmitted power via magnetic induction. A rectifier circuit connected between the second inductor and the second transmission line converts electrical power output therefrom into DC electrical power and supplies the DC electrical power to the second transmission line. A feedback circuit maintains the frequency of the drive signal at the value for maximum power transfer. The RF signal transmission circuitry includes apparatus connected to the second transmission line to receive broadband RF signals therefrom and produce a pair of differentially balanced feed signals. The feed signals are capacitively coupled across window glass and fed into a coaxial cable for transmission to the receiver.