Design of a Multiband Stacked Microstrip Patch Antenna for Satellite Communications Application

In this thesis, a multiband stacked patch antenna for satellite communications is proposed. Since handheld devices used for satellite communications are mainly monopole antennas, this thesis explores the possibilities of developing a microstrip patch antenna that can be integrated in the satellite communications’ handheld devices. Therefore, a designed antenna for satellite communications that operates around the two bands 1.487 GHz and 1.578 GHz is proposed. The antenna composes of two stacked patches with total dimensions of 45 x 45 mm and 40 x 40 mm for the lower and upper patches, respectively, separated by FR_4 as a dielectric material. The proposed antenna is designed using the method of moments simulator of ADS and the simulations results show good performance in satellite communications bands with gain of 3.42 dBi and circular polarization from 1.453 GHz to 1.478 GHz. Additionally, the antenna shows multiple matching frequencies that can be used for other purposes along with the satellite communications. Moreover, this antenna is simple, easy to fabricate and manufacture, and implement on different devices comparing to other monopole antennas that serve the same purpose

An Ultra-Wideband Circularly Polarized Asymmetric-S Antenna With Enhanced Bandwidth and Beamwidth Performance

This paper introduces an ultra-wideband circularly polarized (CP) asymmetric-S antenna with wide axial ratio beamwidth (ARBW) for C-band applications. The proposed antenna is realized by bending a linearly polarized dipole into asymmetric-S shape with variable trace width, which achieves CP radiation. Unlike the reported symmetric-S antenna, the proposed antenna is constituted with two unequal curved arms to enhance the bandwidth and beamwidth performances. Compared with the symmetric-S antenna, the proposed antenna demonstrates much wider AR bandwidth and wider ARBW over broader frequency range. A prototype is fabricated to verify the design principle. The measured and simulated results are very consistent and both indicate that the proposed antenna has a wide impedance bandwidth (VSWR <; 2) of 70.2% (3.58 to 7.46 GHz), and a wide 3-dB AR bandwidth of 84.8% (2.75 to 6.8 GHz). Moreover, maximum ARBW of 153° is achieved, and a 3-dB ARBW of more than 100° is maintained within a wide operation bandwidth of 46.3% (3.65-5.85 GHz)

A Compact Two-Level Sequentially Rotated Circularly Polarized Antenna Array for C

A compact circular polarized antenna array with a convenient gain/bandwidth/dimension trade-off is proposed for applications in the C-band. The design is based on the recursive application of the sequential phase architecture, resulting in a 4 × 4 array of closely packed identical antennas. The 16 antenna elements are disc-based patches operating in modal degeneration, tuned to exhibit a broad while imperfect polarization. Exploiting the compact dimension of the patches and a space-filling design for the feeding network, the entire array is designed to minimize the occupied area. A prototype of the proposed array is fabricated with standard photoetching procedure in a single-layer via less printed board of overall area 80 × 80 mm2. Adequate left-hand polarization is observed over a wide bandwidth, demonstrating a convenient trade-off between bandwidth and axial ratio. Satisfying experimental results validate the proposed design, with a peak gain of 12.6 dB at 6.7 GHz maintained within 3 dB for 1 GHz, a very wide 10 dB return loss bandwidth of 3 GHz, and a 4 dB axial ratio bandwidth of 1.82 GHz, meaning 31% of fractional bandwidth

Quasi-Optical Multi-Beam Antenna Technologies for B5G and 6G mmWave and THz Networks: A Review

Multi-beam antennas are critical components in future terrestrial and non-terrestrial wireless communications networks. The multiple beams produced by these antennas will enable dynamic interconnection of various terrestrial, airborne and space-borne network nodes. As the operating frequency increases to the high millimeter wave (mmWave) and terahertz (THz) bands for beyond 5G (B5G) and sixth-generation (6G) systems, quasi-optical techniques are expected to become dominant in the design of high gain multi-beam antennas. This paper presents a timely overview of the mainstream quasi-optical techniques employed in current and future multi-beam antennas. Their operating principles and design techniques along with those of various quasi-optical beamformers are presented. These include both conventional and advanced lens and reflector based configurations to realize high gain multiple beams at low cost and in small form factors. New research challenges and industry trends in the field, such as planar lenses based on transformation optics and metasurface-based transmitarrays, are discussed to foster further innovations in the microwave and antenna research community

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

Wideband Dual-Circular-Polarization Antennas for Millimetre-Wave Wireless Communications.

PhD Theses.Millimetre-wave (mmWave) wireless communications has attracted great interest in recent years as a promising technology that can provide high data rate beyond 5G. Circular Polarization (CP) radiation is preferable to Linear Polarization (LP) in mmWave wireless communications, owing to the reliability of the wireless link it provides to suppress multi-path fading and polarization misalignment. Apart from the link robustness, high link capacity is also desirable by introducing technologies such as Polarization Division Multiplexing (PDM) or In-Band Full-Duplex (IBFD). Therefore, this research aims to design dual-circular-polarization (dual-CP) antennas with wide bandwidth and high port isolation to enable PDM or IBFD for mmWave wireless communications thereby achieving twofold spectral e ciency. The research work has been conducted in the following four parts. Firstly, a dual-CP horn antenna based on a stepped septum polarizer is designed in the W-band. By optimising the horn pro le, a wide bandwidth with good isolation is achieved in simulation and veri ed in experiment. Secondly, to further push the limits of the dual-CP antenna based on the stepped septum polarizer, a grooved-wall septum polarizer is proposed for the rst time with a 2-step design method to realize a dual-CP antenna with wider operating bandwidth and higher port isolation. Thirdly, in order to ease the fabrication di culty and further improve the antenna performance, a novel grooved-wall CP horn antenna is designed in simulation and veri ed in experiment in the W-band. The dual CP performance can be generated when used with an Orthomode Transducer (OMT), instead of a septum. Finally, this septum-free approach has been generalised to design a multi-section groovedi wall CP horn antenna with a low re ection coe cient over a wide bandwidth in the W-band. This horn antenna is demonstrated to be capable of achieving dual-CP with high isolation over a wide bandwidth when used together with an OMT

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

Reconfigurable Antennas

In this new book, we present a collection of the advanced developments in reconfigurable antennas and metasurfaces. It begins with a review of reconfigurability technologies, and proceeds to the presentation of a series of reconfigurable antennas, UWB MIMO antennas and reconfigurable arrays. Then, reconfigurable metasurfaces are introduced and the latest advances are presented and discussed

Antenna Designs for 5G/IoT and Space Applications

This book is intended to shed some light on recent advances in antenna design for these new emerging applications and identify further research areas in this exciting field of communications technologies. Considering the specificity of the operational environment, e.g., huge distance, moving support (satellite), huge temperature drift, small dimension with respect to the distance, etc, antennas, are the fundamental device allowing to maintain a constant interoperability between ground station and satellite, or different satellites. High gain, stable (in temperature, and time) performances, long lifecycle are some of the requirements that necessitates special attention with respect to standard designs. The chapters of this book discuss various aspects of the above-mentioned list presenting the view of the authors. Some of the contributors are working strictly in the field (space), so they have a very targeted view on the subjects, while others with a more academic background, proposes futuristic solutions. We hope that interested reader, will find a fertile source of information, that combined with their interest/background will allow efficiently exploiting the combination of these two perspectives