Beam-Steering Performance of Flat Luneburg Lens at 60 GHz for Future Wireless Communications

Abstract

The beam-steering capabilities of a simplified flat Luneburg lens are reported at 60 GHz. The design of the lens is first described, using transformation electromagnetics, before discussion of the fabrication of the lens using casting of ceramic composites. The simulated beam-steering performance is shown, demonstrating that the lens, with only six layers and a highest permittivity of 12, achieves scan angles of ±30 ∘ with gains of at least 18 dBi over a bandwidth from 57 to 66 GHz. To verify the simulations and further demonstrate the broadband nature of the lens, raw high definition video was transmitted over a wireless link at scan angles up to 36 ∘ . Background and MotivationsThe quest for ubiquitous wireless connectivity with everincreasing data rates has been a feature of the last half century. With the advent of the Internet of Things (IoT) adding huge numbers of devices requiring bandwidth to an alreadychallenging push for even greater data rates to be supported on personal wireless terminals, considerable research effort is being invested into future wireless networks. High-data rate applications include the streaming of ultrahigh definition video and virtual and augmented reality (e.g., [1,2]); the use of 60 GHz for these applications is now relatively wellestablished, with IEEE standards (e.g., 802.15.3c, 802.11ad[3]) well-suited for this aspect of 5G services and networks.Other aspects of 5G development are concerned with serving greater numbers of end-terminals and reducing latency, with some applications in the IoT relevant to this (even when data rate requirements are not severe).A large number of technologies are being brought together to achieve the various aims for the next generation of wireless networks [4]. This includes the use of small cells (where the density of base stations is increased), cooperative communications (where interference is reduced via communication between nodes, to improve achievable data rates and reliability), carrier aggregation (where bandwidth from disparate channels is combined to meet requirements), and heterogeneous networks (where multiple networks operating at different frequencies and with different modulations, etc., are used). One key technology is massive multi-input-multioutput (M-MIMO) systems, where the number of antennas is increased by at least an order of magnitude (e.g., [5][6][7]).One key approach to realise the objectives of future wireless networks is to utilise previously unused parts of the electromagnetic spectrum at higher frequency bands, particularly the millimetre-wave (mm-wave) and terahertz (THz) bands. Currently, wireless networks predominantly use the spectrum between 0.1 and 10 GHz, as these have offered key benefits of long propagation ranges, ease of fabrication, and ease of power generation and signal modulation, amongst others. Conversely, the higher bands must overcome increased propagation losses, smaller feature sizes that increase fabrication challenges, and other problems; the demand for bandwidth is such that these challenges...

Asymmetrical Three-Dimensional Conformal Imaging Lens

“…Finally, it is necessary to discuss the possible experimental preparation and application prospects of 2D and 3D lenses. Of all the lenses mentioned in this article, the Luneburg lens is currently the most widely used, with many applications in both 2D and 3D, such as wireless communication [42], radar systems [43], and optical focusing [44]. In terms of preparation, because of its good gradient refractive index interval (1-1.4) and rotational symmetry, it can be designed easily by effective media theory using metamaterials [20,44].…”

3D-Printed Conformal Meta-Lens with Multiple Beam-Shaping Functionalities for Mm-Wave Sensing Applications

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A Low-Cost 60-GHz Modular Front-End Design for Channel Sounding

“…Contemporary research in the 60 GHz band, shows a high dependency on commercially available off-the-shelf (COTS) frontends, e.g., [2][3][4][5][6][7][8][9][10][11][12][13][14]. However, COTS offers are limited and the majority of the referred research has depended on a single manufacturer.…”