Ridged waveguide phased array elements

W-band Waveguide Antenna Elements for Wideband and Wide-Scan Array Antenna Applications For Beyond 5G

“…A single ridge is adopted inside the WG structure to lower the cut-off frequency of its fundamental mode, thus providing a wideband low-dispersive operation [9] with transverse element size close to 0.5λ 0 (λ 0 is the free-space wavelength corresponding to the central design frequency f 0 ). Various open-ended ridge WG elements have been studied previously including dual-and quad-ridge element designs [10], [11]. However, the reported wideband beam-steering performance was limited due to impedance mismatch (e.g., VSWR < 4 in the 11% bandwidth and 60 • scan range for the X-band array element with half-wavelength E-plane size at central frequency in [10]).…”

“…Various open-ended ridge WG elements have been studied previously including dual-and quad-ridge element designs [10], [11]. However, the reported wideband beam-steering performance was limited due to impedance mismatch (e.g., VSWR < 4 in the 11% bandwidth and 60 • scan range for the X-band array element with half-wavelength E-plane size at central frequency in [10]). In this study, we employ several wideband techniques to improve the element's active reflection coefficient during beam steering.…”

“…This allows for > 0.5λ 0 inter-element-spacing for grating lobe-free wide-angle beam steering. The increased H-plane spacing is also beneficial for lowering the WG cut-off frequency and It is well know that open-ended WG array antennas have relatively strong antenna element mutual coupling effects [12], [10]. This can be a limiting factor of the bandwidth and scan range, where the latter often results in scan-blindness.…”

Improved performance from double ridge waveguide arrays

“…Overall, the element aperture area could be 1.5 times that of the rectangular waveguide. The reason that the ridged waveguide element is seldom utilized is due to the high active reflection coefficient encountered [4,5,6] and the absence of an effective way to improve the scan match. This is partly caused by the comparatively narrow widths of the ridges used in these designs.…”

Approximation by Gegenbauer polynomials in the study of a rectangular ridged waveguide. Application to the analysis of a waveguide septum polarizer

“…conventional rectangular waveguide having the same internal dimensions. It was indeed used as transmission waveguide, matching or transition elements, filter elements, cavity elements, in the slow-wave structure, in the phased array elements and finally as polarizer elements [2,[3][4][5][6]. In 1947, Cohn [3] obtained, for the first time, ridged waveguide eigenvalues of TE mo modes by using the transverse resonance method in a cross section of a ridged wave-guide.…”