Motor-vehicle windshield with built-in antenna/heating conductors

Abstract

A windshield has a generally upright transparent panel, an array of horizontal and generally parallel heater conductors on the panel and having opposite ends, and respective conductive busses connected to the heater conductors at the opposite ends thereof. Thus electricity can be applied to the busses to pass current through the heater conductors and thereby heat the panel at the array. A pair of generally upright, generally parallel, and horizontally spaced antenna conductors on the panel extend across and connect at crossing locations to the heater conductors and an output conductor is connected electrically to the antenna conductors so that radio-frequency output is taken off the output conductor. The crossing locations of each of the antenna conductors are all located at points of the same potential on the respective heater conductors and the only direct electrical connection between the pair of antenna conductors is through the heater conductors. The output conductor can be connected to one of the heater conductors and therethrough to the antenna conductors. It can also be connected directly to one of the antenna conductors and indirectly via a nonresistive impedance to the other antenna conductor. This nonresistive impedance can be a capacitor or an inductor. It is also possible to connect both the antenna conductors via such a nonresistive impedance to the output conductor.