A Planar UHF-Band Ultrawideband Modular Antenna Array With Tapered Probes Feed

This article presents a dual-polarized planar ultrawideband modular antenna (PUMA) array, aimed at scaling its operating frequency directly to the ultrahigh-frequency (UHF) range. In contrast to the traditional PUMA designs that use closely spaced probes feeding, the proposed design employs tapered probes with larger separation for feeding the array. This architecture enables the antenna to retain the desirable characteristics of unbalanced feeding, ease of manufacturing, and straightforward assembly while avoiding the introduction of additional shorting pins or "cable organizers" and complex external matching networks typically required to eliminate common-mode resonances and achieve wideband performance. Additionally, the use of tapered probes not only eliminates the requirement for any substrate material between the antenna and the ground plane but also inherently contributes to enhancing the polarization isolation. The wide-angle impedance matching layer is implemented using advanced 3-D printing technology, which minimizes the need for multiple substrate layers and adhesive processes and contributes to cost reduction. As an evaluation, an array is meticulously designed to operate across a wide bandwidth of 6.1:1 (0.52-3.19 GHz) with an active VSWR < 3 while scanning within a range of +/- 45 degrees in all planes. The polarization isolation surpasses 15 dB throughout the majority of the bandwidth when undergoing +/- 45 degrees scans in the E- and H-planes. An $8\times8$ prototype array consisting of 128 ports, with 64 elements per polarization, is manufactured and assessed. The experimental findings validate the design as the measured data closely align with the simulated results. The proposed antenna offers significant advantages, such as ultrawideband (UWB), wide scanning range, low cost, and modularity, which make it holds great potential for meeting the evolving demands of modern communication systems.