Periodic leaky-wave array antenna on substrate integrated waveguide for gain enhancement

A Magnetoelectric Dipole Leaky-Wave Antenna for Millimeter-Wave Application

Abstract: This paper presents a novel frequency beam scanning slotted leaky-wave magnetoelectric (ME) dipole antenna array for the fifth generation (5G) application. The proposed antenna, which has eighteen elements of slots and electric dipoles, is built on a two-layer printed circuit board. In the lower layer, it is a conventional slotted substrate integrated waveguide (SIW) leaky-wave antenna (LWA). In the upper layer, electric dipoles are attached to the design. As for each element unit, the magnetic dipole is realized by each lower-layer aperture, while the electric dipole is realized by each pair of patches in the upper layer. The design concept is that two modes are excited together in orthogonal directions to realize the ME dipole. By introducing electric dipoles to the conventional slotted LWA, the antenna exhibits less gain variation over a wide bandwidth. The SIW leaky-wave ME dipole antenna array is designed and fabricated to operate at the 28-GHz band. It operates with wide impedance bandwidth and a peak gain of 16.55 dBi with less than 3-dB gain variation throughout the frequency range from 27 to 32 GHz.

Bidirectional periodic leaky-wave antenna on SIW with reduced side lobe level

Abstract: In this paper, a bidirectional periodic leaky-wave antenna (LWA) using substrate integrated waveguide (SIW) based power divider is presented at X-band. Later, by incorporating new kind of slot, side-lobe level (SLL) is improved by 1 dB. The gain is achieved by proposed antenna is 12.1 dBi within a suitable scanning range. The performance of both antennas are compared by Ansoft HFSS simulation software.

Gain Enhancement of a Substrate Integrated Waveguide Slot Array for Millimeter Waves

Abstract: An approach to enhance the gain of a slot antenna array located on the top wall of a substrate integrated waveguide (SIW) is investigated in this paper. The design procedure consists of two steps. We begin by designing a single slot antenna element located on the top wall of an SIW waveguide, and then we proceed to enlarge it to a full-fledged 4x5 slot array. Following this we further enhance the performance of the array by introducing a Metasurface superstrate above the antenna array. Simulation results are presented for the return loss and gain of the designed array to illustrate its performance. For the unloaded array, a low return loss of less than −10 dB is realized from 27 GHz to 34 GHz with a peak gain of 14.34 dB at 30 GHz. Up to 3 dB gain improvement is achieved, over the bare array, when a Metasurface superstrate is introduced.

CRLH based leaky-wave antenna using modified Minkowski fractal on SIW with tunable frequency band

Abstract: In this paper, a composite right/left-handed (CRLH) based frequency tunable compact high gain leaky-wave antenna (LWA) is proposed at Ku-band. For miniaturization purpose, the modified Minkowski fractal geometry is utilized and by incorporating with suitably placed varactor diodes, the frequency tunable leaky-wave antenna is designed in planar environment. By changing the position of varactor diodes the operating frequency range of the antenna is shifted from 15–16.2 GHz to 14–15 GHz with the beam scanning range of 32° and 30° respectively. The obtained peak gain is 16.7 dBi. Full-wave simulations are performed in HFSS.

Electromagnetic metamaterials : transmission line theory and microwave applications : the engineering approach

Abstract: Preface. Acknowledgments. Acronyms. 1 Introduction. 1.1 Definition of Metamaterials (MTMs) and Left-Handed (LH) MTMs. 1.2 Theoretical Speculation by Viktor Veselago. 1.3 Experimental Demonstration of Left-Handedness. 1.4 Further Numerical and Experimental Confirmations. 1.5 "Conventional" Backward Waves and Novelty of LH MTMs. 1.6 Terminology. 1.7 Transmission Line (TL) Approach. 1.8 Composite Right/Left-Handed (CRLH) MTMs. 1.9 MTMs and Photonic Band-Gap (PBG) Structures. 1.10 Historical "Germs" of MTMs. References. 2 Fundamentals of LH MTMs. 2.1 Left-Handedness from Maxwell's Equations. 2.2 Entropy Conditions in Dispersive Media. 2.3 Boundary Conditions. 2.4 Reversal of Doppler Effect. 2.5 Reversal of Vavilov- Cerenkov Radiation. 2.6 Reversal of Snell's Law: Negative Refraction. 2.7 Focusing by a "Flat LH Lens". 2.8 Fresnel Coefficients. 2.9 Reversal of Goos-H anchen Effect. 2.10 Reversal of Convergence and Divergence in Convex and Concave Lenses. 2.11 Subwavelength Diffraction. References. 3 TLTheoryofMTMs. 3.1 Ideal Homogeneous CRLH TLs. 3.1.1 Fundamental TL Characteristics. 3.1.2 Equivalent MTM Constitutive Parameters. 3.1.3 Balanced and Unbalanced Resonances. 3.1.4 Lossy Case. 3.2 LC Network Implementation. 3.2.1 Principle. 3.2.2 Difference with Conventional Filters. 3.2.3 Transmission Matrix Analysis. 3.2.4 Input Impedance. 3.2.5 Cutoff Frequencies. 3.2.6 Analytical Dispersion Relation. 3.2.7 Bloch Impedance. 3.2.8 Effect of Finite Size in the Presence of Imperfect Matching. 3.3 Real Distributed 1D CRLH Structures. 3.3.1 General Design Guidelines. 3.3.2 Microstrip Implementation. 3.3.3 Parameters Extraction. 3.4 Experimental Transmission Characteristics. 3.5 Conversion from Transmission Line to Constitutive Parameters. References. 4 Two-Dimensional MTMs. 4.1 Eigenvalue Problem. 4.1.1 General Matrix System. 4.1.2 CRLH Particularization. 4.1.3 Lattice Choice, Symmetry Points, Brillouin Zone, and 2D Dispersion Representations. 4.2 Driven Problem by the Transmission Matrix Method (TMM). 4.2.1 Principle of the TMM. 4.2.2 Scattering Parameters. 4.2.3 Voltage and Current Distributions. 4.2.4 Interest and Limitations of the TMM. 4.3 Transmission Line Matrix (TLM) Modeling Method. 4.3.1 TLM Modeling of the Unloaded TL Host Network. 4.3.2 TLM Modeling of the Loaded TL Host Network (CRLH). 4.3.3 Relationship between Material Properties and the TLM Model Parameters. 4.3.4 Suitability of the TLM Approach for MTMs. 4.4 Negative Refractive Index (NRI) Effects. 4.4.1 Negative Phase Velocity. 4.4.2 Negative Refraction. 4.4.3 Negative Focusing. 4.4.4 RH-LH Interface Surface Plasmons. 4.4.5 Reflectors with Unusual Properties. 4.5 Distributed 2D Structures. 4.5.1 Description of Possible Structures. 4.5.2 Dispersion and Propagation Characteristics. 4.5.3 Parameter Extraction. 4.5.4 Distributed Implementation of the NRI Slab. References. 5 Guided-Wave Applications. 5.1 Dual-Band Components. 5.1.1 Dual-Band Property of CRLH TLs. 5.1.2 Quarter-Wavelength TL and Stubs. 5.1.3 Passive Component Examples: Quadrature Hybrid and Wilkinson Power Divider. 5.1.3.1 Quadrature Hybrid. 5.1.3.2 Wilkinson Power Divider. 5.1.4 Nonlinear Component Example: Quadrature Subharmonically Pumped Mixer. 5.2 Enhanced-Bandwidth Components. 5.2.1 Principle of Bandwidth Enhancement. 5.2.2 Rat-Race Coupler Example. 5.3 Super-compact Multilayer "Vertical" TL. 5.3.1 "Vertical" TL Architecture. 5.3.2 TL Performances. 5.3.3 Diplexer Example. 5.4 Tight Edge-Coupled Coupled-Line Couplers (CLCs). 5.4.1 Generalities on Coupled-Line Couplers. 5.4.1.1 TEM and Quasi-TEM Symmetric Coupled-Line Structures with Small Interspacing: Impedance Coupling (IC). 5.4.1.2 Non-TEM Symmetric Coupled-Line Structures with Relatively Large Spacing: Phase Coupling (PC). 5.4.1.3 Summary on Symmetric Coupled-Line Structures. 5.4.1.4 Asymmetric Coupled-Line Structures. 5.4.1.5 Advantages of MTM Couplers. 5.4.2 Symmetric Impedance Coupler. 5.4.3 Asymmetric Phase Coupler. 5.5 Negative and Zeroth-Order Resonator. 5.5.1 Principle. 5.5.2 LC Network Implementation. 5.5.3 Zeroth-Order Resonator Characteristics. 5.5.4 Circuit Theory Verification. 5.5.5 Microstrip Realization. References. 6 Radiated-Wave Applications. 6.1 Fundamental Aspects of Leaky-Wave Structures. 6.1.1 Principle of Leakage Radiation. 6.1.2 Uniform and Periodic Leaky-Wave Structures. 6.1.2.1 Uniform LW Structures. 6.1.2.2 Periodic LW Structures. 6.1.3 Metamaterial Leaky-Wave Structures. 6.2 Backfire-to-Endfire (BE) Leaky-Wave (LW) Antenna. 6.3 Electronically Scanned BE LW Antenna. 6.3.1 Electronic Scanning Principle. 6.3.2 Electronic Beamwidth Control Principle. 6.3.3 Analysis of the Structure and Results. 6.4 Reflecto-Directive Systems. 6.4.1 Passive Retro-Directive Reflector. 6.4.2 Arbitrary-Angle Frequency Tuned Reflector. 6.4.3 Arbitrary-Angle Electronically Tuned Reflector. 6.5 Two-Dimensional Structures. 6.5.1 Two-Dimensional LW Radiation. 6.5.2 Conical-Beam Antenna. 6.5.3 Full-Space Scanning Antenna. 6.6 Zeroth Order Resonating Antenna. 6.7 Dual-Band CRLH-TL Resonating Ring Antenna. 6.8 Focusing Radiative "Meta-Interfaces". 6.8.1 Heterodyne Phased Array. 6.8.2 Nonuniform Leaky-Wave Radiator. References. 7 The Future of MTMs. 7.1 "Real-Artificial" Materials: the Challenge of Homogenization. 7.2 Quasi-Optical NRI Lenses and Devices. 7.3 Three-Dimensional Isotropic LH MTMs. 7.4 Optical MTMs. 7.5 "Magnetless" Magnetic MTMs. 7.6 Terahertz Magnetic MTMs. 7.7 Surface Plasmonic MTMs. 7.8 Antenna Radomes and Frequency Selective Surfaces. 7.9 Nonlinear MTMs. 7.10 Active MTMs. 7.11 Other Topics of Interest. References. Index.

Review of substrate-integrated waveguide circuits and antennas

Abstract: Substrate-integrated waveguide (SIW) technology represents an emerging and very promising candidate for the development of circuits and components operating in the microwave and millimetre-wave region. SIW structures are generally fabricated by using two rows of conducting cylinders or slots embedded in a dielectric substrate that connects two parallel metal plates, and permit the implementation of classical rectangular waveguide components in planar form, along with printed circuitry, active devices and antennas. This study aims to provide an overview of the recent advances in the modelling, design and technological implementation of SIW structures and components.

Leaky-Wave Antennas

Abstract: This paper gives a basic review and a summary of recent developments for leaky-wave antennas (LWAs). An LWA uses a guiding structure that supports wave propagation along the length of the structure, with the wave radiating or “leaking” continuously along the structure. Such antennas may be uniform, quasi-uniform, or periodic. After reviewing the basic physics and operating principles, a summary of some recent advances for these types of structures is given. Recent advances include structures that can scan to endfire, structures that can scan through broadside, structures that are conformal to surfaces, and structures that incorporate power recycling or include active elements. Some of these novel structures are inspired by recent advances in the metamaterials area.

Leaky‐Wave Antennas

Abstract: This chapter contains sections titled: Introduction History Classification of Leaky‐Wave Antennas Physics of Leaky Waves Radiation Properties of One‐Dimensional Leaky‐Wave Antennas Radiation Properties of Two‐Dimensional Leaky‐Wave Antennas Conclusions Acknowledgment References