Abstract: A detection system (100) and a method for identifying structural change (300) with a substrate (200) includes a sensor (101) configured to resonate at variable frequencies, the resonant frequency of the sensor changing in response to structural change in the substrate, a detector (102) located in proximity to the sensor for detecting the resonant frequency of the sensor, and a receiving device (103) in communication with the detector for receiving information output by the detector, an analyzing device (108) in communication with the receiving device for and interpreting information output by the receiving device. The sensor includes an engagement surface for engaging the substrate. The detector is located on the sensor and away from the engagement surface in such a way that the sensor and the detector are arranged to form a laminated structure.

Abstract: The present invention provides a patch antenna comprising a patch spaced from a ground plane and two L-shaped feed probes. Each feed probe is connected to a respective input port and has a portion extending parallel to the patch. The antenna further includes at least two walls extending from the ground plane towards the patch. The walls are positioned between the L-shaped feed probes so as to permit direct propagation between the input ports and also to create indirect diffraction paths between the input ports that serve to cancel at least a part of said direct propagation.

Abstract: The present invention provides a patch antenna comprising a patch spaced from a ground plane and two L-shaped feed probes. Each feed probe is connected to a respective input port and has a portion extending parallel to the patch. The antenna further includes at least two walls extending from the ground plane towards the patch. The walls are positioned between the L-shaped feed probes so as to permit direct propagation between the input ports and also to create indirect diffraction paths between the input ports that serve to cancel at least a part of said direct propagation.