摘要:
A resonant radar reflector assembly comprising first and second reflector members (110A, 110B), the first and second and reflector members each being configured to resonate at their respective resonant frequency when irradiated by radio frequency (RF) radiation of a corresponding frequency, wherein the first member has a portion (114A) responsive to an electric field applied parallel to an electric polarisation axis of the first member, the second member having a corresponding portion (114B) responsive to an electric field applied parallel to a corresponding electric polarisation axis of the second member, the first member also having a portion (112A) responsive to a magnetic field applied parallel to a magnetic polarisation axis of the first member, the second member having a corresponding portion (112B) responsive to a magnetic field applied parallel to a corresponding magnetic polarisation axis of the second member, the first and second members being arranged such that at least one electric or magnetic polarisation axis of the first member is substantially not parallel to the corresponding electric or magnetic polarisation axis of the second member.
摘要:
A sensor comprising: a sensor resonant radar reflector member; and a sensor element, the sensor reflector member being configured to resonate at a resonant frequency when irradiated by radio frequency radiation of a corresponding frequency, the sensor being further configured whereby exposure of the sensor element to a target measurand causes a change in the resonant frequency of the sensor reflector member.
摘要:
Embodiments of the present invention provide a resonant assembly (105,305,405,700,750,930), comprising first and second resonant members (110,410), the first and second resonant members each being configured to resonate at a respective different resonant frequency when excited by an electromagnetic field, wherein at least one resonant member comprises a discontinuous loop (112, 710, 760) having at least one capacitive element (114,720,721,722,770,771,772) connected between free-ends of the loop.
摘要:
A resonant assembly for identification of a buried asset comprising first and second resonant members each configured to resonate at a respective different resonant frequency when excited by an electromagnetic field. The resonant assembly is arranged to cause a near-field coupling of transmit and receive antenna of a detector at the first and second resonant frequencies such that identification of the resonant assembly is performed at least in part according to the frequencies of the coupling.
摘要:
A resonant radar reflector assembly comprising first and second reflector members (110A, 110B), the first and second and reflector members each being configured to resonate at their respective resonant frequency when irradiated by radio frequency (RF) radiation of a corresponding frequency, wherein the first member has a portion (114A) responsive to an electric field applied parallel to an electric polarization axis of the first member, the second member having a corresponding portion (114B) responsive to an electric field applied parallel to a corresponding electric polarization axis of the second member, the first member also having a portion (112A) responsive to a magnetic field applied parallel to a magnetic polarization axis of the first member, the second member having a corresponding portion (112B) responsive to a magnetic field applied parallel to a corresponding magnetic polarization axis of the second member, the first and second members being arranged such that at least one electric or magnetic polarization axis of the first member is substantially not parallel to the corresponding electric or magnetic polarization axis of the second member.
摘要:
A tripolar antenna is described having at least two electromagnetic signal transmitting/receiving elements arranged such that their axes of signal transmission/reception sensitivity are not parallel, wherein said elements are provided on or at least partially in a substrate of dielectric material so portions of said at least two elements are coplanar and dielectrically isolated from one another. In a preferred arrangement, two dipoles are provided on the substrate in perpendicular orientation and in the plane containing of the surface of said dielectric material. Most preferably a further third element is provided so as to render the antenna tripolar, said third element comprising a first circular disk element secured to an upper surface of the dielectric material, and a second slightly larger circular disk element, concentrically positioned on the corresponding opposite and lower surface of the dielectric.
摘要:
A tripolar antenna is described having at least two electromagnetic signal transmitting/receiving elements arranged such that their axes of signal transmission/reception sensitivity are not parallel, wherein said elements are provided on or at least partially in a substrate of dielectric material so portions of said at least two elements are coplanar and dielectrically isolated from one another. In a preferred arrangement, two dipoles are provided on the substrate in perpendicular orientation and in the plane containing of the surface of said dielectric material. Most preferably a further third element is provided so as to render the antenna tripolar, said third element comprising a first circular disk element secured to an upper surface of the dielectric material, and a second slightly larger circular disk element, concentrically positioned on the corresponding opposite and lower surface of the dielectric.