Concentric ring array of connecting spirals with WAVES

A dual circularly polarized wideband array working over a 2:1 bandwidth was previously developed. This array had the following requirements: 2:1 bandwidth, capable of steering up to 30° in theta, dual circular polarization, Relative Sidelobe Level (RSLL) < −10dB, Axial Ratio (AR) < 3dB and reflection coefficient (S
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) < −10dB. In this paper, we extend the array bandwidth to 15:1 through adding connections between the arms of neighboring spirals to improve the S
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at lower frequencies and using the WAVES (Wideband Array with Variable Element Size) technique to reduce the RSLL at higher frequencies.