A 10.5–14.5 GHz wide-scanning connected array of dipoles with common-mode rejection loops to ensure polarization purity

Due to electrical connection between the array elements, standard baluns typically used in arrays of resonant dipoles are not effective for connected arrays. Therefore, a novel Printed Circuit Board (PCB) solution to avoid common-mode resonances, without resorting to active components or MMIC technology, is proposed in this paper. It consists in a loop-shaped component that rejects the common mode, allowing the design of connected arrays with X-pol levels lower than -15 dBs over a relative bandwidth that exceeds 30%. Simulated results obtained via Ansoft HFSS are presented for validation.