摘要 |
<p>A sensor assembly, particularly suitable for use on a vehicle wheel to sense, e.g. the pressure within a vehicle tyre, comprises a patch antenna (3) and a SAW device (2). The patch antenna comprises conductive sheets (4, 5) of substantially equal surface area separated by a dielectric spacer (6). The SAW device may be located between the plates (3, 5) within the thickness of the dielectric material. The patch antenna may be secured to the wheel rim of a vehicle wheel so that one of the antenna plates is capacitively coupled to the metal of the wheel thereby forming an extended ground-plane. Such an arragement produces a low profile sensor/antenna combination which has a maxiumum gain in the radial direction of the wheel.</p> |