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We present the results of measurements of the radar signature of a new type of wind turbine, named the Wind Lens. This design includes a shroud around the turbine which concentrates the wind flow past the turbine blades and hence improves the efficiency. The design also offers improved safety, and reduces acoustic noise. Furthermore, it may offer a significantly lower radar signature, which may make the design much more attractive for use in situations where conventional wind turbine designs may disturb the operation of radars in an unacceptable manner.

A voltage controlled oscillator using a SAW resonator does not need multiplication and tuning in the 100 MHz ‐ UHF band so that miniaturization and circuit simplification can be achieved. It also has the feature that less power is dissipated than with a SAW delay line. In this paper the SAW resonator voltage‐controlled oscillator (SAWR‐VCO) is used as a modulator suitable for a phase locked loop (PLL) and its modulation sensitivity and distortion are analyzed. Tests confirm the analysis of SAWR‐VCO performance. Finally a PLL modulator structure and the modulator circuit for use in an automotive mobile telephone unit is described.

We study the radar signature of a new type of wind turbine, named the Wind Lens. This design includes a flanged shroud around the turbine which concentrates the wind flow past the turbine blades and hence improves the efficiency. The design also offers improved safety, and reduces acoustic noise. Furthermore, it may offer a significantly lower radar signature, which may make the design much more attractive for use in situations where conventional wind turbine designs may disturb the operation of radars. We present the results of an experimental trial, carried out in the UK, to measure the Radar Cross Section (RCS) of a 5 kW Wind Lens turbine prototype and we provide a reference database that can be used for comparing the Wind Lens RCS with that of conventional turbines. We investigate methods to further reduce the Wind Lens RCS and present the results of a time-varying Doppler analysis. Results show that the addition of a metallic mesh around the shroud obscures the rotating blades, and hence mitigates the RCS by 15 dBm 2 , at angles where the radar interference is highest.