A Broadband Low-Profile Circularly Polarized Radial Line Slot Antenna

Matthieu Bertrand (1, 2) , Mauro Ettorre (3) , Guido Valerio (2) , Matteo Albani (4) , M. Casaletti (1)

1 Thales Research and Technology [Palaiseau]
2 GeePs - Laboratoire Génie électrique et électronique de Paris
3 IETR - Institut d'Électronique et des Technologies du numéRique
4 DII - Department of Information Engineering [Sienne]

This paper presents a circularly polarized Corporate-Fed Radial-Line Slot Antenna (CF-RLSA) operating in Ka-band and realized in low-cost, low-profile printed circuit board (PCB) technology. The radiating aperture is fed by a corporate feed network based on a broadband pillbox-like circular transition. The proposed feeding system results in a 67% gain bandwidth improvement compared to classical center-fed RLSA designs. Pattern stability versus frequency is also achieved. The bandwidth improvement provided by the corporate-feed topology is analytically derived for the general case of circular apertures with uniform amplitude illumination. This predicted improvement is confirmed by measurements. The prototype is optimized using a dedicated numerical tool, then fabricated and characterized. A good agreement is obtained between simulated and measured gain bandwidths, with a demonstrated relative bandwidth of 6.9% at 29 GHz for a maximum gain of 35.5 dBi and a 260 mm diameter for the radiating aperture.

Keywords: Radial Slot Line Antenna (RLSA); leaky-wave antenna; pillbox; optimization

Domains: Engineering Sciences [physics]

Matthieu Bertrand, Mauro Ettorre, Guido Valerio, Matteo Albani, M. Casaletti. A Broadband Low-Profile Circularly Polarized Radial Line Slot Antenna. IEEE Transactions on Antennas and Propagation, 2023, 71 (1), pp.140 - 150. ⟨10.1109/tap.2022.3218761⟩. ⟨hal-03956212⟩