Abstract: High amplitude signals reflected back to the horn radiator-receptor in a microwave tank-contents measuring assembly from the interface between a microwave dielectric lens and the tank-contents-atmosphere, which reflected signals mimic returning ranging signals and interfere with detection of returning legitimate ranging signals, are substantially canceled by incorporating in the lens which is plano-convex a thin layer of electrically conductive material in a plane parallel to the plano surface of the lens, said layer being formed from a uniform array of a repetitive pattern of regions containing the conductive material alternating with regions free of said material. One embodiment has an hexagonal array of circular conductive regions while another embodiment has the conductive material in the form of a rectilinear grid.

Abstract: A method and device for measuring the distance to an object, particularly the distance to the surface (17) of a liquid in a container (15). An antenna (11) is arranged a distance from and aimed against the surface, the antenna being connected to a measuring unit (12), a channel unit (13) and a control unit (14). A microwave signal with a predetermined frequency is generated in the measuring unit (12), of which a part is utilized as a reference signal, while a further part is input to the antenna (11) and transmitted against the surface (17). From the reflected signal received by the antenna and supplied to the measuring unit (12) and the reference signal, a function of the antenna input reflection coefficient is determined. This function is adapted to the current condition. A fourier transformation of a set of values of this function at a certain set of measuring frequencies is made, from which the distance to the surface is calculated.

Abstract: In a circuit for driving a plasma display panel, a blocking oscillator produces pulses varying between a positive and a negative voltage. Transistors controlled by first selection signals selectively supply first electrodes of the panel with either the complete bipolar pulses, or with only a predetermined one of the positive or negative pulse components. Further transistor switches controlled by second selection signals selectively connect and disconnect second display panel electrodes to ground. A constant voltage is applied to the disconnected second electrodes.A gas discharge occurs at each intersection of the first electrodes supplied with the full bipolar pulse wave and the grounded second electrodes. In accordance with one aspect of the present invention, production of the driving pulses may be suspended either by a preselected one of the first and second selection signals or by coincidence logic operating upon preselected first or second selection signals.