Modified planar Luneburg lens millimetre‐wave antenna for wide‐angle beam scan having feed locations on a straight line

Abstract

This study presents the design and characterisation of a modified planar Luneburg lens antenna operating at 30 GHz. A parallel plate lens structure with varying separation between the metal plates realises the required variation of phase velocity of the guided TE mode in the device. The focal points for different beam radiation directions are all placed on a straight line, thus simplifying the mechanical setup for steered beam and multi‐beam systems. A planar slotline radiator excites the TE mode in the parallel plate structure. An optimisation process leads to best compromise between large directivity, large maximum scan angle and small side‐lobes. As a result, measurements show that by moving the feed radiator on a straight line over ±40 mm, the beam maximum can be steered over more than ±35° with a gain drop of <3 dB. While scanning the beam from broadside direction towards ±35° scan angle, the worst‐case side‐lobe level deteriorates from 15 dB to about 10.5 dB. The proposed antenna shows peak directivity of 15.2 dBi and a large simulated power efficiency of 95%.

Wide-Angle Beam-Switching Antenna with Stable Gain Based on a Virtual Image Lens

“…Parallel plate waveguide (PPW) quasi-optical beamformers provide attractive properties for antenna systems at high frequencies (typically above 20 GHz) [3][4][5][6][7][8][9][10][11][12][13][14]. Importantly, these beamformers can enable beam steering over a wide field of view without costly and lossy circuitry, which makes them attractive for future communication systems.…”

“…Importantly, these beamformers can enable beam steering over a wide field of view without costly and lossy circuitry, which makes them attractive for future communication systems. Specifically, non-rotationally symmetric quasi-optical beamforming antennas have demonstrated beam steering up to ±50 • [3][4][5][6][7][8]. A wider steering range can be obtained using antennas based on rotationally symmetric lenses, e.g., Luneburg lenses [9][10][11][12][13][14].…”

V-Band Fully Metallic Geodesic Luneburg Lens Antenna

“…Two-dimensional (2D) Luneburg lens antennas are typically implemented in parallel plate waveguide (PPW) technology [10]- [24]. The gradient refractive index of the lens can be mimicked with a quasi-periodic structure [14], [16], [20], PPWs with varying air gap [13], [15], [17], or a geodesic surface [10]- [12], [24]. The operation of Luneburg lenses based on fully-metallic quasi-periodic structures has been broadly demonstrated at Ka-band.…”

“…However, as the frequency increases, the periodic inclusions become smaller and their manufacturing results in complex and costly hardware [25], [26]. The lenses based on PPWs with varying air gaps have no small details, and therefore, the manufacturing complexity of these lenses is significantly lower [13], [15], [17]. On the other hand, these lenses typically operate with the dispersive TE1 PPW mode and are therefore limited in bandwidth.…”

An electrically adjustable multibeam lens antenna

“…[4][5][6][7] So far, researchers mainly use the following methods to research and design multibeam lens antenna. For example, beam scanning can be realized by changing the position of the feed, [8][9][10][11] different feed combinations to realize multibeam function. [12][13][14][15][16] In addition, the combination of phased array antenna and lens is also a research hotspot.…”