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

• US 5,612,652 A
• Filed: 03/04/1996
• Issued: 03/18/1997
• Est. Priority Date: 03/04/1996
• Status: Expired due to Term

• Current Assignee: Nortek Security & Control LLC (Melrose Industries Plc)
• Original Assignee: Multiplex Technology, Inc. (Melrose Industries Plc)
• Inventors: Crosby, John B.
• Primary Examiner(s): GENSLER, PAUL L
• Application Number:
  US08/610,327
• Time in Patent Office: 379 Days
• Field of Search: 333/24 R, 333/24 C, 343/711, 343/713, 343/715, 343/859
• US Class Current: 333/24.00R
• CPC Class Codes: H01Q 1/1285 with capacitive feeding through the windscreen
• CPC Class Codes: H04B 1/1607 Supply circuits converters H02M; filters therefor H02M1/14; voltage stabilisers G05F1/46
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04N 5/38 Transmitter circuitry for the transmission of television signals according to analogue transmission standards H04N5/14 takes precedence
• CPC Class Codes: H04N 5/63 Generation or supply of power specially adapted for television receivers
• CPC Class Codes: H04N 7/20 Adaptations for transmission via a GHz frequency band, e.g. via satellite

Abstract

An interface device permits installation of a video system by directing 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 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 balanced feed signals. The feed signals are capacitively coupled across window glass and fed into a coaxial cable for transmission to the receiver.

Claims

1. An interface circuit for transmitting electrical signals between a first transmission line that is connected to a receiver on a first side of a dielectric layer and a second transmission line that is connected to antenna electronics on a second side of the dielectric layer, comprising:

power transmission circuitry that includes;

a first inductor mounted adjacent the first side of the dielectric layer and connected to the first transmission line to receive DC electrical power therefrom;

a switch connected to the inductor, the switch being arranged to convert the DC power received by the inductor into time-varying electrical signals that produce a time-varying magnetic field;

a second inductor mounted adjacent the dielectric layer opposite the first inductor, the second inductor being within the time-varying magnetic field such that electrical power is transmitted through the dielectric layer via magnetic induction; and

a rectifier circuit connected between the second inductor and the second transmission line to convert electrical power output therefrom into DC electrical power and supply the DC electrical power to the second transmission line; and

RF signal transmission circuitry that includes;

apparatus connected to the second transmission line to receive broadband RF signals therefrom and produce a pair of balanced feed signals;

a first pair of plates mounted adjacent the second side of the dielectric layer;

a second pair of plates mounted adjacent the first side of the dielectric layer;

the first and second pairs of plates being arranged to conduct the RF signals from the second transmission line across the dielectric layer; and

apparatus connected between the second pair of plates to convert the balanced feed into an unbalanced feed that is input to the first transmission line.