An apparatus for radio communication using surface waves, the apparatus comprising: a guiding medium having a first surface suitable for the propagation of surface waves, the first surface having a reactive impedance; at least one communication node, the node having a transmitter and/or receiver coupled to a transducer, the transducer positioned on or adjacent the first surface of said guiding medium; wherein the at least one communication node is arranged to launch and/or receive surface waves, over the first surface of said guiding medium.

Apparatus for the transmission of electromagnetic waves

Ice sensors for wind turbines

A disposable sensor is disclosed for non-invasively detecting and characterizing a container's contents. By generating microwave frequency signals, electromagnetic fields are produced by a sensor and penetrate a container. The EM fields are analyzed in regards to how they are perturbed by the container contents. Analysis of the perturbed EM fields enables determination of content level, content purity, content density, content temperature, container pressure, and content conductivity.

Noninvasive electromagnetic fluid level sensor

A universal air bubble detector allows for use with a variety of sizes and types of tubing. The detector maintains proper alignment of a sensor emitter and receiver with different sizes of tubing. The detector may be mounted on existing equipment or may be used to monitor a tubing at any position along the tubing, and may operate in a stand alone mode or in combination with existing equipment.

Method for making and using an air bubble detector

A surface condition sensing system (10) includes a frequency controlled source (12) of electromagnetic power adapted to produce a band of selected frequencies which are directed to a surface (16) under examination. A monitoring circuit (20, 23) compares transmitted and reflected electromagnetic power as a function of frequency from the surface, and generates a plurality of absorption signals representing the difference between the amplitude of the transmitted signal (15) with the corresponding amplitude of the reflected signal (17). An evaluator circuit (23) generates a surface condition signal (42) representing the results of a comparison between the plurality of absorption signals with known surface models. A control circuit (23) generates a status signal representative of the surface condition. The system can be configured as a road condition sensor or as an aircraft ice detection sensor.

Surface condition sensing system

A system for detecting ice on exterior surfaces of aircraft by transmitting a relatively low power microwave electromagnetic signal into a dielectric layer functioning as a surface waveguide, and monitoring the signals transmitted into and reflected from the waveguide. The waveguide includes a termination element which is mismatched with the waveguide impedance, resulting in partial or total reflection of the microwave energy from the remote end of the waveguide. As ice builds up on the surface waveguide, the impedance or reflection characteristics of the composite waveguide comprising the ice layer and the permanent surface waveguide give a reliable indication of the presence and location of the ice. The reflection characteristics are conventionally monitored utilizing a dual directional coupler and a reflectometer.

Magenheim Bertram

Papers

Microwave ice detector

Mit mikrowellen arbeitender eis-detektor