Abstract: A microstrip antenna has an electrically conductive base plate carrying an electrically insulating substrate on top of which are a plurality of radiating patches, the improvement comprises establishing a relatively large spacing between the electrically insulating substrate and the base plate at lateral dimensions larger than lateral dimensions of the patches and in the vicinity of the patches and either through local elevations of the insulating substrate or by local indents in the base plate being vertically aligned with the patches.

Abstract: Carrying structure of an active antenna in the aerospace industry uses basically fiber reinforced synthetic material in which heat conductive elements and/or elements conducting electromagnetic waves (electro, optic) are integrated into that support structure for the antenna.

Abstract: A moisture sensor comprises a moisture-sensitive layer formed from the oxide of highly resistive porous low density tantalum on a moisture-insensitive substrate. Between the substrate and the moisture-sensitive tantalum oxide layer there is a base electrode of an anodically oxidizable metal, preferably tantalum, of a density higher than the density of the low density tantalum from which the tantalum oxide layer is formed. A covering electrode partially covering the tantalum oxide layer has windows through which the water vapor containing medium can penetrate into the moisture-sensitive tantalum oxide layer. The inactive regions of the tantalum oxide layer disposed below the windows are removed to increase the rate of response.