Single end-fire antenna for dual-beam and broad beamwidth operation at 60 GHz by artificially modifying the permittivity of the antenna substrate

Beamwidth radiation in the E-plane of a printed bow-tie antenna operating over 57–64 GHz. This is achieved by artificially modifying the dielectric constant of the antenna substrate using arrays of metamaterial inclusions realized using stub-loaded H-shaped unit cells to provide a high index of refraction. The H-shaped inclusions are tilted with respect to the axis of the antenna and embedded in the direction of the end-fire radiation. The resulting dual-beam radiation in the E-plane has maxima at +60° and 120° with respect to the end-fire direction (90°), with a maximum peak gain of 9 dBi at 60 GHz

Beam Splitting Planar Inverted F Antenna For 5G Communication

A planar inverted-F antenna with symmetrical split beams and loaded with radio frequency absorbers (here Eccosorb MCS) for 5G communication is proposed. The multi-beam antennas reduce the requirement of number of antennas and provide wide coverage. But they require a complex system such as a phased array or MIMO antennas. On the other hand, multi-beam antennas do not have such requirements. In this work, we propose a PIFA antenna which achieves multi-beam behaviour by six slabs of absorbers placed periodically between the PIFA patch and substrate to split the beams into two directions at +26°. The proposed antenna obtains a frequency band of 24.2- 25.7 GHz and achieves a high gain of approximately 10 dB at +26°. The performance of the proposed antenna is suitable for G communication. All simulations of the antenna are carried out using Ansys HFSS. The design was validated by simulations and later confirmed with measurements. &nbsp

1-D broadside-radiating leaky-wave antenna based on a numerically synthesized impedance surface

A newly-developed deterministic numerical technique for the automated design of metasurface antennas is applied here for the first time to the design of a 1-D printed Leaky-Wave Antenna (LWA) for broadside radiation. The surface impedance synthesis process does not require any a priori knowledge on the impedance pattern, and starts from a mask constraint on the desired far-field and practical bounds on the unit cell impedance values. The designed reactance surface for broadside radiation exhibits a non conventional patterning; this highlights the merit of using an automated design process for a design well known to be challenging for analytical methods. The antenna is physically implemented with an array of metal strips with varying gap widths and simulation results show very good agreement with the predicted performance

Beam scanning by liquid-crystal biasing in a modified SIW structure

A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium

Design, Modelling, and Characterisation of Millimetre-Wave Antennas for 5G Wireless Applications

PhDFuture 5G systems and beyond are expected to implement compact and versatile antennas in highly densifi ed millimetre-wave (MMW) wireless networks. This research emphasises on the realisation of 5G antennas provided with wide bandwidth, high gain, adaptable performance, preferably conformal implementation, and feasible bulk fabrication. Ka{band (26.5{40 GHz) is selected based on recent 5G standardisation, and novel antenna geometries are developed in this work on both rigid and flexible substrates by implementing advanced techniques of frequency reconfi guration, multiple-input-multiple- output (MIMO) assembly, as well as wideband and multiband antennas and arrays. Nove lMMW wideband antennas are presented for 5G and spatial diversity at the antenna front-ends is substantially improved by deploying wideband antennas in a MIMO topology for simultaneous multiple-channel communication. However, wideband operation is often associated with efficiency degradation, which demands a more versatile approach that allows the adaptable antenna to select the operating frequency. In this research, high performance recon figurable antennas are designed for frequency selection over Ka- {band. Also, an efficient and conformal antenna front-end solution is developed, which integrates both frequency recon guration and MIMO technology. Gain of the antenna is critically important for 5G systems to mitigate high propagation losses. Antenna design with both high gain and bandwidth is challenging as wideband antennas are traditionally gain-limited, while antenna arrays deliver high gain over a narrow bandwidth. An Enhanced Franklin array model is proposed in this thesis, which aggregates multiband response with high gain performance. Furthermore, novel flexible monopole antenna and array con gurations are realised to attain high gain profi le over the complete Ka{band. These proposed 5G antennas are anticipated as potential contribution in the progress towards the realisation of future wireless networks.EECS Fees Waiver Award and National University of Sciences and Technolog