Abstract: A wind turbine including a support structure and one or more turbine blades is presented, that incorporates ways for reducing the radar cross section (RCS), wherein the support structure is notionally divided into an upper section in the shadow of the blade sweep area, and a lower section beneath the upper section, wherein the upper section is adapted to have the ways for reducing the RCS, and the lower section does not have the adaptation. The invention makes use of the realisation that the blade masking the tower as it rotates (or the blade being masked by the tower if facing away from a radar), contributes significantly to interference to radar systems, and so localised application of e.g. RAM can give good RCS reduction at a lower cost than treating the whole structure.

Abstract: A wind turbine including a support structure and one or more turbine blades is presented, that incorporates ways for reducing the radar cross section (RCS), wherein the support structure is notionally divided into an upper section in the shadow of the blade sweep area, and a lower section beneath the upper section, wherein the upper section is adapted to have the ways for reducing the RCS, and the lower section does not have the adaptation. The invention makes use of the realisation that the blade masking the tower as it rotates (or the blade being masked by the tower if facing away from a radar), contributes significantly to interference to radar systems, and so localised application of e.g. RAM can give good RCS reduction at a lower cost than treating the whole structure.

Abstract: A wind turbine comprising a support structure and one or more turbine blades is disclosed, that incorporates means for reducing the radar cross section (RCS), wherein the support structure is notionally divided into an upper section in the shadow of the blade sweep area, and a lower section beneath the upper section, wherein the upper section is adapted to have the means for reducing the RCS, and the lower section does not have the said adaptation. The invention makes use of the realization that the blade masking the tower as it rotates (or the blade being masked by the tower if facing away from a radar), contributes significantly to interference to radar systems, and so localized application of e.g. RAM can give good RCS reduction at a lower cost than treating the whole structure.

Abstract: A wind turbine including a support structure and one or more turbine blades is presented, that incorporates ways for reducing the radar cross section (RCS), wherein the support structure is notionally divided into an upper section in the shadow of the blade sweep area, and a lower section beneath the upper section, wherein the upper section is adapted to have the ways for reducing the RCS, and the lower section does not have the adaptation. The invention makes use of the realisation that the blade masking the tower as it rotates (or the blade being masked by the tower if facing away from a radar), contributes significantly to interference to radar systems, and so localised application of e.g. RAM can give good RCS reduction at a lower cost than treating the whole structure.

Abstract: A wind turbine blade includes a multilayer composite structure including a first reflective layer, and a second layer including a plurality of resistive circuit analog (CA) elements. The CA elements are tuned so as to interact with the first layer to provide absorption of electromagnetic (EM) energy over a desired frequency range. The parameters of the CA elements can be varied to provide for frequency tuning and to maintain absorption at a specific frequency range despite varying layer separation, while at the same time ensuring that the mechanical properties of the CA layer are compatible with integration into the turbine blade.

Abstract: A wind turbine blade includes a multilayer composite structure including a first reflective layer, and a second layer including a plurality of resistive circuit analogue (CA) elements. The CA elements are tuned so as to interact with said first layer to provide absorption of electromagnetic (EM) energy over a desired frequency range. The parameters of the CA elements can be varied to provide for frequency tuning and to maintain absorption at a specific frequency range despite varying layer separation, while at the same time ensuring that the mechanical properties of the CA layer are compatible with integration into the turbine blade.

Abstract: A device for attenuating electromagnetic radiation in a desired transmission frequency band. The device includes a generally planar substrate, and a resistive pattern arranged on the substrate adapted to reflect a proportion of incident radiation in the transmission band. The resistive pattern may be screen printed using carbon based ink. This provides a simple, cheap and easy to fabricate device which can quickly and easily be affixed to the exterior of an antenna or antenna housing to attenuate the power of radiation in the transmission band, resulting in reduced range or sensitivity.