Novel UWB low-profile sinuous slot antenna

A novel planar low profile UWB sinuous slot radiating element suitable for ESM and ECM systems applications is presented. The radiating element is designed to cover a frequency band wider than one octave (i.e. 3:1) and to be a very “low profile” antenna: its size along boresight axis is smaller than λ₀/4, where λ₀ is the wavelength at the central frequency of operation. The design of a novel sinuous slot feeding structure is presented to achieve such goal. The realisation and characterisation of a sinuous prototype is presented showing very promising electrical results in terms of Return Loss, Gain @ Boresight and Half Power Beamwidth (HPBW).