Showing papers in "Journal of Electromagnetic Waves and Applications in 2014"
TL;DR: In this article, the authors proposed the use of metamaterial-based perfect absorbers (MMPAs) for invisibility cloaking, perfect absorption and transmission, etc.
Abstract: Metamaterials are artificially-engineered materials, possessing properties which are not readily observable in materials existing in nature. Since they show very novel properties such as left-handed behavior, negative refractive index, classical analog of electromagnetically-induced transparency, extraordinary transmission, negative Doppler effect, and so on, they can be used for perfect lens, invisibility cloaking, perfect absorption and transmission, etc. Metamaterial-based perfect absorbers (MMPAs) are promising candidates for the practical application of perfect absorbers. MMPA is usually composed of three layers. The first layer is periodically-arranged metallic patterns, whose structure and geometrical parameters should be carefully adjusted to fulfill the impedance-matching condition with the ambient, allowing no reflection of incident electromagnetic (EM) waves. The second layer is a dielectric layer, which allows a space for the EM waves to be dissipated, and sometimes plays a role of resonance c...
115 citations
TL;DR: In this article, a comprehensive study on effects of coil shapes is conducted, in particular, helix coils, planar spiral coils, and square-helix coils are studied, and it is shown that the helix coil offers the best performance (e.g., the highest efficiency, the widest bandwidth, and the longest transfer distance) under optimal load whereas the planar coil exhibits the worst performance among these three types of coils.
Abstract: The wireless system with four coil resonators is a popular configuration for mid-range wireless power transfer (WPT) via magnetic resonance coupling. The design parameters of four coils have strong impact on efficiency, bandwidth, and transfer distance of the WPT system. In this work, a comprehensive study on effects of coil shapes is conducted. In particular, helix coils, planar spiral coils, and square helix coils are studied. It is shown that the helix coils offer the best performance (e.g. the highest efficiency, the widest bandwidth, and the longest transfer distance) under optimal load whereas the planar spiral coils exhibit the worst performance among these three types of coils. Nevertheless, the performance of the WPT system with helix coils degrades more rapidly than these with other two types of coils when the distance between the transmitting and receiving coils increases.
50 citations
TL;DR: In this paper, the influence of constant magnetic constituents on the radiation of high-energy electrons in a planar undulator was analyzed and the effect of the constant magnetic field on the UR was compared with other common spectrum distortions in UR sources.
Abstract: We analyze the influence of constant magnetic constituents on the radiation of high-energy electrons in a planar undulator. Broadening and spectrum shift effect of the constant field is compared with other common spectrum distortions in undulator radiation (UR) sources. Analytical formulation of the effect of the constant magnetic field enables us to obtain and study exact expressions for the UR intensity. They reveal the possibilities to influence off-the-axis effects and give practical recommendations for the undulators with radiation properties, best profitable for free-electron lasers.
44 citations
TL;DR: In this article, a new mathematical model of the equations of two-temperature magneto-thermo-viscoelasticity theory for a perfect conducting solid has been constructed in the context of a new consideration of heat conduction with a time-fractional derivative of order and a time fractional integral of order.
Abstract: A new mathematical model of the equations of two-temperature magneto-thermo-viscoelasticity theory for a perfect conducting solid has been constructed in the context of a new consideration of heat conduction with a time-fractional derivative of order and a time-fractional integral of order . This model is applied to one-dimensional problem for a perfect conducting half-space of elastic solid with heat source distribution in the presence of a constant magnetic field. Laplace transforms and state-space techniques will be used to obtain the general solution for any set of boundary conditions. A numerical method is employed for the inversion of the Laplace transforms. According to the numerical results and its graphs, conclusions about the new theory are given. Some comparisons are shown in figures to estimate the effects of the fractional order parameters and the temperature discrepancy on all the studied fields.
43 citations
TL;DR: In this paper, an ultrafast fractional magneto-thermoelasticity model utilizing the modified hyperbolic heat conduction model with fractional order is formulated to describe the thermo-elastic behavior of a thin perfect conducting metal film irradiated by a femtosecond laser pulse.
Abstract: An ultrafast fractional magneto-thermoelasticity model utilizing the modified hyperbolic heat conduction model with fractional order is formulated to describe the thermoelastic behavior of a thin perfect conducting metal film irradiated by a femtosecond laser pulse. Some theorems of generalized thermoelasticity follow as limit cases. The temporal profile of the ultrafast laser was regarded as being non-Gaussian. An analytical–numerical technique based on the Laplace transform was used to solve the governing equations and the time histories of the temperature, displacement, stress, strain, and induced electric/magnetic fields in a gold film were analyzed. Some comparisons have been shown in figures to estimate the effects of some parameters on all the studied fields.
43 citations
TL;DR: In this paper, a novel three-band microwave metamaterial absorber is presented, which consists of a metallic planar cross and square layer on the top and a metallic ground plane at the bottom.
Abstract: In this paper, a novel three-band microwave metamaterial absorber is presented. The proposed absorber consists of a metallic planar cross and square layer on the top and a metallic ground plane at the bottom. They are separated by a dielectric layer. The experimental results show that the proposed absorber exhibits triple band absorption responses lying in C-band, X-band, and Ku-band. The proposed absorber can perform absorption peaks at three resonant frequencies of 6.16, 8.76, and 12.54 GHz with the absorption of 99.87, 99.98, and 99.99% can be acquired, respectively. In addition, the absorber can operate at large incident angles for both TE and TM polarization.
38 citations
TL;DR: The ability to shrink the physical dimensions of an antenna without significant performance degradation has been of great interest for over half a century as mentioned in this paper, and several antenna miniatu cation techniques have been proposed.
Abstract: The ability to shrink the physical dimensions of an antenna without significant performance degradation has been of great interest for over half a century. Over the decades, several antenna miniatu...
37 citations
TL;DR: In this paper, the authors used COMSOL Multiphysics software and MATLAB to model a cold anisotropic magnetized plasma, described by full-3D non-uniform dielectric tensor, enclosed by the metallic cylindrical cavity where the plasma is formed.
Abstract: Electromagnetic wave propagation in anisotropic media has been widely studied over the last decades since there are several applications where anisotropy plays an important role. This paper presents a procedure to carry out three-dimensional (3D) finite element method (FEM) full-wave simulations of the electromagnetic field in inhomogeneous magnetized plasma of an electron cyclotron resonance ion source (ECRIS). We used COMSOL Multiphysics software and MATLAB to model a cold anisotropic magnetized plasma, described by full-3D non-uniform dielectric tensor, enclosed by the metallic cylindrical cavity where the plasma is formed. A proper mesh generation, exploiting FEM-based COMSOL versatility, allowed us to optimally model ECRIS cavity and microwave waveguide launching structure, with a good computational efficiency and high resolution of the solution especially around the resonance regions. Numerical simulations have been performed in the frequency domain: in the resonance regions especially, the material...
36 citations
TL;DR: In this article, a measuring circuit was designed and developed to directly measure the top electrode voltage in the 27'MHz 6'kW RF unit together with the anode current read from the RF generator.
Abstract: Top electrode voltage of a radio frequency (RF) heating system is an important parameter to accurately determine final sample temperatures using computer simulation. The purpose of this study was to establish the correlation between the top electrode voltage obtained by analytical method or simulation and the measured electrical currents. A measuring circuit was designed and developed to directly measure the top electrode voltage in the 27 MHz 6 kW RF unit together with the anode current read from the RF generator. The top electrode voltage was experimentally determined with 3 kg soybeans under five electrode gaps using computer simulation based on the matched temperature profiles in three layers, and analytical methods based on the heating rates measured by infrared camera, fiber optic sensors and thermocouples. Results showed that the electrode voltage decreased with increasing electrode gap or decreasing heating rate. The correlation between the electrode voltage estimated by temperature distributions ...
35 citations
TL;DR: In this article, a metamaterial absorber based on discontinuous cross-wire-strip (CWS) resonators is proposed to achieve very high absorptions at wide angles of incidence for both transverse electric and transverse magnetic waves.
Abstract: This study presents design, fabrication, and measurement of a metamaterial absorber (MA) based on discontinuous cross-wire-strip (CWS) resonators. This suggested that MA has a simple geometry configuration and introduces perfect absorption approximately 99.79% at 3.42 GHz for simulation and 99.72% at 3.44 GHz for experiment. In addition, the designed model can be used to realize the broadband absorber for desired frequency ranges. Besides, numerical simulations validate that the MA could achieve very high absorptions at wide angles of incidence for both transverse electric and transverse magnetic waves. The experimental results are in good agreement with the numerical simulations. Moreover, this study presents a numerical analysis in order to explain physical interpretation of MA mechanisms in detail. The proposed model and its variations enable myriad potential applications such as stealth and radar technologies.
33 citations
TL;DR: In this paper, a multilayer sphere with a fixed external radius and with an arbitrary number of layers is considered as a possible realization of a radial uniaxial (RU) sphere.
Abstract: We consider a multilayer sphere with a fixed external radius and with an arbitrary number of layers as a possible realization of a radial uniaxial (RU) sphere. We start from the well-known quasi-static model for the polarizability of the multilayer sphere and, after a validation with a dynamic code previously presented, we try to understand the limits in which the multilayer sphere can be considered a RU sphere. We employ different techniques for layering the spheres and we find which of them is convenient in terms of convergence speed. Moreover, we deal with the case of plasmonic layers and we find some rules for the realization of the multilayer sphere in order to obtain the desired homogenized parameters. Finally, we present a study on the behavior of plasmon resonances of the multilayer sphere when the number of layers is increased.
TL;DR: In this paper, a dual-band circularly polarized (CP) antenna was proposed by using a single-band CP radiator on a finite artificial magnetic conductor (AMC) surface, which employed a 90° phase delay line consisting of a vacant-quarter printed ring to generate broadband CP radiation.
Abstract: This paper proposes a new way of designing a dual-band circularly polarized (CP) antenna by using a single-band CP radiator on a finite artificial magnetic conductor (AMC) surface. The AMC surface consists of a lattice of square metal plates on grounded dielectric substrate while the single-band radiator is a compact crossed dipole, which employs a 90° phase-delay line consisting of a vacant-quarter printed ring to generate broadband CP radiation. The dual-band operation is obtained by utilizing the original band generated by the radiator and the first additional band caused by surface waves propagating on the finite AMC surface. For verifying the design method, the proposed antenna is optimized for the L1 and L2 bands of the global positioning system with low-profile broadband characteristics and excellent CP radiation. The final design with an overall size of 85 × 85 × 11.493 mm3 (~0.3485λo × 0.3485λo × 0.0471λo at the 1.23 GHz) yields a measured impedance bandwidth of 1.202–1.706 GHz for the |S11| < –1...
TL;DR: In this article, a large-signal empirical model for GaN HEMT devices using an improved Angelov drain current formulation with self-heating effect and a modified non-linear capacitance model is presented.
Abstract: This paper presents a large-signal empirical model for GaN HEMT devices using an improved Angelov drain current formulation with self-heating effect and a modified non-linear capacitance model. The established model for small gate-width GaN HEMTs is validated by on-wafer load-pull measurements up to 14 GHz. Moreover, a scalable large-signal model is presented by adding scalable parameters to drain-source current and non-linear capacitance equations. The scalable model of a 1.25 mm GaN HEMT has been employed to design a class-AB power amplifier for validation purposes. The results show that good agreement has been achieved between the simulated and measured results with 37.2 dBm saturation output power (Psat) and 58% maximum power-added-efficiency at 3 GHz.
TL;DR: In this article, the authors address the dynamics of bright and singular optical solitons in quadratic nonlinear media and use the ansatz approach for integration of this model.
Abstract: This paper addresses the dynamics of bright and singular optical solitons in quadratic nonlinear media. The ansatz approach is the tool of integration of this model. The 1-soliton solution is obtai...
TL;DR: Results demonstrate that EWT is more efficient than wavelet transform in terms of sparsity representation, and the proposed EWT–ISTA can obtain less MAE & MSE, and higher PSNR than ISTA, with comparable computation time.
Abstract: In this paper, we propose a novel sparse transform dubbed exponential wavelet transform (EWT), which provides sparser coefficients than the conventional wavelet transform. We also propose a reconstruction algorithm EWT–ISTA that takes advantages of both EWT and ISTA. Experiments compare the proposed EWT–ISTA with conventional ISTA method that takes wavelet transform as sparsity domain. We employ five different kinds of MR images, i.e. the phantom, the brain, the leg, the arm, and the uterus images. The results demonstrate that: (1) EWT is more efficient than wavelet transform in terms of sparsity representation, and (2) the proposed EWT–ISTA can obtain less MAE & MSE, and higher PSNR than ISTA, with comparable computation time.
TL;DR: In this article, the design, preparation, and electromagnetic testing of wideband dielectric absorbers based on carbon fibers and carbon black powders for stealth applications was presented, and the specially prepared absorbers were characterized using the partially filled waveguide technique for the complex permittivity and the return loss of the sample is measured using the free-space system in the X-band frequency region.
Abstract: This paper presents the design, preparation, and electromagnetic testing of wideband dielectric absorbers based on carbon fibers and carbon black powders for stealth applications. The specially prepared absorbers are characterized using the partially filled waveguide technique for the complex permittivity, and the return loss of the sample is measured using the free-space system in the X-band frequency region. A maximum return loss of 29 dB i.e. absorption of 99% at 10.3 GHz is achieved with minimum 97% absorption throughout the X-band frequency region. The fabricated absorber having density of 0.28 gm/cc and thickness of 2 mm makes it a potential candidate for stealth applications especially for the defense targets. A multilevel fast multipole method-based electromagnetic simulation is carried out on the artillery shell model, and on the leading edge model of the aircraft using the measured electromagnetic properties of designed absorber for the radar cross-section (RCS) reduction. The maximum RCS reduct...
TL;DR: In this paper, a new type of printed periodic leaky-wave antenna is proposed, which is able to continuously scan a beam from backward to forward endfire, without being a quasi-homogeneous metamaterial structure.
Abstract: A new type of printed periodic leaky-wave antenna is proposed, which is able to continuously scan a beam from backward to forward endfire. The unit cell consists of a microstrip line loaded with long lengths of transmission line folded as a U-stub and an interdigital capacitor. This U-stub geometry, which is characterized by a compact longitudinal size, permits operation at frequencies lower than other conventional periodic leaky-wave antennas. At the same time, the presence of the interdigital capacitor makes the radiating U-stub discontinuity self-matching, thus allowing for an elimination of open-stopband effects and for an achievement of an almost constant gain while the beam is scanned through broadside. A noteworthy aspect of the present design is that it represents the first periodic leaky-wave antenna that scans through broadside by radiating from the fundamental harmonic, without being a quasi-homogeneous metamaterial structure.
TL;DR: A universal methodology for designing a ultra-wideband (UWB) diversity antenna using only a familiar symmetrical UWB antenna, a UWB diversity antenna with a compact size, wide impedance bandwidth and good isolation between two feeding ports can be designed conventionally.
Abstract: A universal methodology for designing a ultra-wideband (UWB) diversity antenna is presented in this paper. The main advantage of the methodology is that by using only a familiar symmetrical UWB antenna, a UWB diversity antenna with a compact size, wide impedance bandwidth and good isolation between two feeding ports can be designed conventionally. Another advantage of the methodology is that the distance between two radiators is almost equal to the distance between two feeding lines, thus a complicated structure to decouple the mutual interaction between two radiators is not necessary in the antenna design, and the configuration of the UWB diversity antenna is simple. As an example, a UWB diversity antenna with a compact size of 36 mm × 36 mm operating at a frequency range of 3.1–10.6 GHz designed by using a circular disc monopole UWB antenna is constructed, measured and analysed. The simulated and measured results show that across the UWB, the antenna can achieve a broad impedance bandwidth with good iso...
TL;DR: In this paper, the authors summarize and compare recent advances regarding the technical operation of reconfigurable SIW antennas and the construction of their various topologies, namely half-mode SIW (HMSIW), quarter-mode SiW (QMSIW), and eighth-mode SEW, with respect to the tunable frequency, radiation pattern and polarization.
Abstract: Reconfigurable substrate-integrated waveguide (SIW) technology is considered to be promising for the development of antennas operating in the microwave and millimeter wavebands. The main aim of this study is to summarize and compare recent advances regarding the technical operation of reconfigurable SIW antennas and the construction of their various topologies, namely half-mode SIW (HMSIW), quarter-mode SIW, and eighth-mode SIW, with respect to the tunable frequency, radiation pattern, and polarization. The classic development of SIW components is concisely described, and a comparative analysis of the simulation results for the different SIW topologies is also presented, focusing on how SIW antennas are reconfigured as per system needs.
TL;DR: In this work, a narrowband fully passive printable RFID chipless tag, working in the UHF band, is presented, which uses spectral signatures to encode data, and hence provides a unique ID for every tagged object.
Abstract: In this work, a narrowband fully passive printable RFID chipless tag, working in the UHF band, is presented. The tag consists of two cross-polarized transmitting and receiving microstrip broadband circular monopole antennas, loaded with multiple cascaded resonators, each one unambiguously corresponding to one data bit. The proposed antenna has a compact size, a low cost of fabrication, and a very compact frequency bandwidth. It uses spectral signatures to encode data, and hence provides a unique ID for every tagged object. The antenna has been designed using a general purpose 3D CAD, CST Microwave Studio, and measured results are in very good agreement with the simulations. The designed RFID tag has been tested in anechoic chamber, and the unique spectral signature of the tag has been correctly detected. The proposed tag design is suitable for mass deployment for low cost items.
TL;DR: In this paper, the conservation laws for optical solitons with spatio-temporal dispersion are obtained and three conserved quantities that are reported in this paper are the power, linear momentum and the Hamiltonian.
Abstract: The conservation laws for optical solitons with spatio-temporal dispersion are obtained in this paper. There are three conserved quantities that are reported in this paper. They are the power, linear momentum, and the Hamiltonian. The conserved quantities, from their respective densities, are obtained from 1-soliton solution that was reported earlier. Five types of nonlinear media are taken into account.
TL;DR: In this paper, a perfect electrically conducting strip placed in homogeneous isotropic chiral medium is investigated using Kobayashi potential (KP) method for left and right circularly polarized electromagnetic plane waves.
Abstract: Scattering of left and right circularly polarized electromagnetic plane waves from a perfect electrically conducting strip placed in homogenous isotropic chiral medium is investigated using Kobayashi Potential (KP) method. The KP method is being employed for the first time to investigate the scattering phenomenon in homogeneous isotropic chiral medium. In the problem formulation, we encounter dual integral equations which are solved using discontinuous properties of Weber–Schafheitlin’s integral. Far zone scattered co- and cross-components are determined numerically using steepest descent method. Dependence of scattered co- and cross-components on angle of incidence and the chirality parameter has been demonstrated through numerical results.
TL;DR: In this article, a power divider with flltering responses is presented, which uses quarter-wavelength resonators with a novel feeding structure, both power division and bandpass responses are obtained, and compact size is realized.
Abstract: This paper presents a novel power divider with flltering responses. By using quarter- wavelength resonators with a novel feeding structure, both power division and bandpass responses are obtained, and compact size is realized. Discriminating coupling is utilized to suppress the third harmonic to obtain wide stopband. The isolation resistor is connected at two ends of the input feed line, and good isolation is obtained. Two transmission zeros are generated at two edges of the passband, resulting in high selectivity. For demonstration, a flltering power divider is implemented. Comparisons of the measured and simulated results are presented to verify the theoretical predications.
TL;DR: In this article, a new method is proposed to be used in designing array antennas in which the slot shape of DGS in the ground plane of the antenna is assumed to be a polygon, and its shape is obtained by using the enhanced genetic algorithm (GA) and ant colony optimization (ACO).
Abstract: The surface wave propagation is a significant problem in designing microstrip array antennas that causes the mutual coupling between array elements. There are several methods to suppress this effect and decrease the propagation of surface waves,such as using defected ground structures (DGS). Determining the shape of DGS is the main difficulty when using these structures. In this paper,a new method is proposed to be used in designing array antennas in which the slot shape of DGS in the ground plane of the antenna is assumed to be a polygon, and its shape is obtained by using the enhanced genetic algorithm (GA) and ant colony optimization (ACO). In this case, an array antenna with two elements is designed to work in 9.5 GHz and the gain, return loss and mutual coupling of this antenna is optimized. Finally, the design procedure is verified by simulation and measurement.
TL;DR: In this article, a rigorous approach is introduced for the exact integration of the complete expressions for the time-harmonic fields of a vertical electric dipole situated on a homogeneous lossy half-space.
Abstract: A rigorous approach is introduced for the exact integration of the complete expressions for the time-harmonic fields of a vertical electric dipole situated on a homogeneous lossy half-space. Analytical integration is made possible by applying the residue theorem after replacing the square root terms of the integrands in the field integrals with their rational function representations according to the Babylonian square root algorithm. As a result, the EM field is explicitly expressed as a superposition of cylindrical waves. The obtained formulas allow to relax all the assumptions underlying King’s formulation for the same Sommerfeld half-space problem. Numerical results are presented to show the validity of the proposed formulation.
TL;DR: A generalized 3-D imaging algorithm is presented for TWI with multiple-input multiple-output (MIMO) radar which is real time in data collection and provides high-quality focused images in various wall-target scenarios.
Abstract: One of the main drawbacks of three-dimensional (3-D) through-the-wall imaging (TWI) with synthetic aperture radar is the long data acquisition time. The movement of the target during the long data collection time in TWI causes smearing and target displacement in the image. In this paper, a generalized 3-D imaging algorithm is presented for TWI with multiple-input multiple-output (MIMO) radar which is real time in data collection. The far field layered medium Green’s function is incorporated in the MIMO through-the-wall beamformer to take into account and compensate for the wall effects. This makes the imaging algorithm simply applicable to the imaging of targets behind either single- or multilayered building walls, which has promising potential application in urban sensing of building interior targets. The MIMO through-the-wall beamformer can also be simply applied to two-dimensional TWI. Numerical results show that the through-the-wall MIMO beamformer provides high-quality focused images in various wall-...
TL;DR: In this paper, the effect of apertures on shielding effectiveness was studied with both circuit modelling method and the finite-difference time-domain (FDTD) method, and the results of SE predictions obtained by the analytical formulation and FDTD method are compared and validated with full-field simulations using the software CST/EMC.
Abstract: Apertures in a rectangular enclosure can be the coupling path of electromagnetic interference. This paper is devoted to the development of approximating phenomenological models in order to estimate the electromagnetic energy coupling through apertures into enclosures. The effect of apertures on shielding effectiveness (SE) of the enclosure is studied with both circuit modelling method and the finite-difference time-domain (FDTD) method. The results of SE predictions obtained by the analytical formulation and FDTD method are compared and validated with full-field simulations using the software CST/EMC. The software code is based on the finite integration technique. The investigation includes accurate calculation of both magnetic and electric shielding as a function of frequency, enclosure dimensions, apertures shapes, position within the enclosure, plane wave incidence mode and the “loaded aperture” approach.
TL;DR: In this paper, the design, analysis, and measurement of a novel frequency selective surface (FSS) is proposed, which works with high selectivity in X-band and wide out of band rejection in C-, C-, and Ku-band.
Abstract: The design, analysis, and measurement of a novel frequency selective surface (FSS) are proposed, which works with high selectivity in X-band and wide out of band rejection in C-band and Ku-band. The proposed FSS is achieved by cascading two-layer periodic arrays of unit cells based on square loop structure. Multiple transmission zeros are obtained for broadening the stopband on the both sides of the passband. The presented double-layer FSS is insensitive to the variation of incident angle and polarization of a striking plane electromagnetic wave. By studying the electric fields and currents excited in the proposed structure, it explains the passband characteristics and the multiple transmission zeros in the two stopbands. Experimental verifications are carried out, which are consistent with the simulated results.
TL;DR: In this paper, a balanced diplexer and a balun Diplexers with high common-mode suppression and differential-mode isolation were proposed for the two channels of 2.45 GHz WLAN and 3.55 GHz WiMAX.
Abstract: A balanced diplexer and a balun diplexer, both designed for the two channels of 2.45-GHz WLAN and 3.55-GHz WiMAX, are proposed with high common-mode (CM) suppression and differential-mode (DM) isolation in this paper. For the balanced diplexer, balanced BPFs for the two desired channels were first designed using stepped-impedance slot-line resonators (SISLRs). Through two T-junctions, the two BPFs were subsequently combined to form a three-balanced-port diplexer having six single-ended ports. Such a balanced diplexer can be easily converted into a balun diplexer with one single-ended and two balanced ports. For that purpose, one of the T-junctions and its associated two feeding lines are removed, and the feeding lines connected to the other T-junction are modified. For both diplexers, the measured CM suppressions (DM isolations) are larger than 54.3 (39.5), 52.2 (44.5), and 40.7 (38.7) dB, respectively, in the lower channel, the upper channel, and the displayed frequency range of 1–6 GHz. A satisfactory a...
TL;DR: In this paper, a multiphysics simulation for a waveguide X-band Fin Taper (FT) Spatial Power Combiner is presented, which uses Fin Lines to microstrip transition (FLuS) to convert the energy from a rectangular waveguide (WG) TE10 fundamental mode to a microstrip (μS) transmission line (TL) quasi-TEM (q-tEM) mode, in order to be amplified by Solid-State Power Amplifiers.
Abstract: This paper describes the design based on a Multiphysics simulation for a waveguide X-Band Fin Taper (FT) Spatial Power Combiner. The proposed device uses Fin Lines to microstrip transition (FLuS) to convert the energy from a rectangular waveguide (WG) TE10 fundamental mode to a microstrip (μS) transmission line (TL) quasi-TEM (q-TEM) mode, in order to be amplified by Solid-State Power Amplifiers. An alteration of the electromagnetic behavior can be produced by the temperature increase and the geometrical displacement induced by the thermal expansion of the structure due to the power dissipation of the MMIC amplifiers. A proper multiphysics model is proposed to select materials and shapes of the probes and their support (carrier), considering the thermo-mechanical operative condition. A virtual prototyping technique is proposed: electric field and S-parameters’ computation in such critical conditions are shown. The proposed study has allowed for the proper thermo-mechanical design for such amplifiers; henc...