Compact Groove Diamond Antenna in Gap Waveguide Technology With Broadband Circular Polarization at Millimeter Waves

Bull’s-Eye Antenna With Circular Polarization at Millimeter Waves Based on Ridge Gap Waveguide Technology

“…1(b) and the values specified in Table I. Although this feeder has a narrower AR BW than the one used in [19], we opted for this solution because it is simpler, easier to fabricate and fits well with the requirements of BE antennas, which are usually narrowband. As demonstrated in the back-to-back (i.e.…”

“…As explained in detail in [19] the CP is generated by the length difference between the two orthogonal arms at the end of the ridge, r and l. In [19], the difference between the left and right arms was nearly λ0/4, giving rise to a phase difference of 90º and therefore to a CP at the output. However, in the present case the length difference between both arms is 0.5 mm which is only λ0/10 (l = 1.28 mm and r = 0.78 mm).…”

“…The structure is fed from the bottom using a WR-15 waveguide to RGW transition (note that this is required by the current experimental setups based on standard waveguides and could be removed in future systems operating entirely in GW technology). CP is generated by two orthogonal arms with different lengths that excite a top diamondshaped slot, although there are some subtle differences with our previous work [19], as explained in Section II below. The top plate contains four concentric periodic corrugations around the diamondshaped slot covering maximally the metallic plane.…”

“…In a recent paper, we demonstrated a diamond slot antenna able to intrinsically produce CP using GW technology [19]. The mechanism to generate CP was simple and effective, based on two orthogonal feeder arms of different lengths placed below the diamond-shaped slot.…”

“…Hence, the second objective of this manuscript is to demonstrate a high-gain antenna with CP by combining the ideas of the diamond slot antenna of [19] with a BE geometry covering maximally the top metallic plane. In this way, we merge together three important concepts: generating CP in a simple way, using GW technology and demonstrating a high-gain in a single antenna without the need of using antenna arrays, which require a complex feeding network [20], [21].…”