Using an overlapping T-block method based on mode-matching technique and virtual current cancellation, the scattering formulations for a metal-only reflectarray antenna composed of multiple rectangular grooves are rigorously presented in fast convergent integrals. By matching normal boundary conditions at boundaries, we get simultaneous equations TE TM modal coefficients plane-wave incidence Hertzian dipole excitation. A metallic-rectangular-grooves fed by pyramidal horn was fabricated...

Abstract A multiplexed Cassegrain reflector antenna with a 2 × open-ended rectangular waveguide (OERW) matrix feed and an orbital angular momentum (OAM) mode mux is proposed for the simultaneous generation of three OAM modes ( l = 0, ±1). The (OMM) was designed using sequential combinations quadrature hybrids, crossovers, phase shifters to multiplex demultiplex at same time. OERW OMM were separately measured their performances verified according theories. near-field measurement conducted...

A dielectric superstrate layer above a microstrip patch antenna has remarkable effects on its gain and resonant characteristics. This paper experimentally investigates the effect of for high antennas. We measured antennas with without found that single was enhanced by about 4 dBi over one at 12 GHz. The impedance bandwidths VSWR < 2 were 11%. designed 2×8 array using had 22.5 dB wide bandwidth 17%.

The scattering solutions for a metallic-rectangular-grooves based two-dimensional (2D) reflectarray antenna excited by an open-ended parallel-plate waveguide are obtained using overlapping T-block method and the Stratton-Chu formula. design formulas of to obtain high directivity beam-tilting effect also proposed in view phase matching condition. characteristics 2D computed terms gain focus offset. We manufactured <i xmlns:mml="http://www.w3.org/1998/Math/MathML"...

A parabolic reflector antenna with an azimuthally deformed Cassegrain subreflector is proposed to effectively generate arbitrary orbital angular momentum (OAM) modes. The dual‐reflector was fabricated for 18 GHz and measured in the near‐field range. far‐field transformed radiation phase around a full azimuth shows that generates fields l = 1 OAM mode. Simulated feed reflection coefficients are below −10 dB 15.1–21.2 GHz, even though distance between horn 15.6 mm, thus it expected structure...

Orbital angular momentum (OAM) mode combining and canceling in the near-field was investigated using a Cassegrain dual-reflectarray antenna composed of multiple microstrip patches on main sub-reflectarrays. Microstrip dielectric substrates were designed to radiate particular OAM modes for arithmetic combining, where two wave-generating reflectarrays are very closely placed near-field. We conducted measurements at 18 [GHz] by manually replacing sub-reflectarray with different numbers 0, ±1,...

Generalization of a Friis transmission equation for orbital angular momentum (OAM) radios is rigorously formulated using the Lorentz reciprocity theorem and near-and-far-field convolution integral (NFCI). Based on discretization NFCIs, we computed generalized to obtain power-receiving behaviors practical helicoidal parabolic reflector antennas (HPRAs) with continuously deformed surfaces. A simplified also used computing link budget approximate Rayleigh length discrete uniform circular arrays...

A T-block (TB) approach is proposed to analyze the dispersion relation of a ridge waveguide. The field representations TB are obtained with Green's function and mode-matching technique. Rigorous, yet simple equations for symmetric asymmetric waveguides presented using superposition overlapping TBs. rapid convergence characteristics equation illustrated in terms cutoff wavenumbers. closed-form relation, based on dominant-mode approximation, shown be accurate most practical applications such...

Transverse magnetic plane-wave scattering from finite rectangular grooves in a conducting plane is systematically analyzed with the overlapping T-block method. Multiple are divided into several T-blocks to obtain fast CPU time, simple applicability, and wide versatility. The field representations within expressed using Green's function relation mode-matching scattered fields obtained closed forms including fast-convergent integral.

The radiation quality factors of vertically and horizontally polarized single-mode dipole antennas over a ground plane are investigated compared with their free-space counterparts. theoretical Q results validated using simulation measurement small spherical helix antennas. For antennas, the bandwidth can be enhanced approximately by factor two.

Using the surface micromachining technology composed of thick photoresist patterning and Cu-metal plating process, Q-band micro-patch antennas were implemented on high resistivity silicon (HRS) substrate. Because application frequency is sufficiently high, monolithically integrated, miniaturized micro find applications in many systems. 42-GHz fed by coupling from micro-strip feeder under patch part. parasitic capacitance posts contacted with HRS substrate, sizes decreased slight decreasing...

We investigate the characteristics of a wideband and high-gain cavity-backed slot antenna in terms reflection coefficients, radiation patterns, gain. A structure includes baffles, reflectors, thick ground planes. The measured gain bandwidth 10-dB return loss 2 × array with h1 = mm, d mm are 15.5 dBi nearly 27%, respectively, at 42 GHz. Baffles reflectors used to increase gain, thus reducing coupling among slots on plane.

The transverse magnetic plane-wave scattering equations for infinite and semi-infinite rectangular grooves (RGs) in a conducting plane are proposed terms of the overlapping T-block method Floquet theorem. By utilising theorem taking limit multiple RGs as number becomes infinity, simultaneous solutions RG then analytically obtained. Combining analyses large yields approximate yet numerically efficient RG. Numerical computations performed to verify that converge fast agree with mode-matching method.

Novel floating-patch micro-electro-mechanical system (MEMS) antennas are proposed for millimetre-wave applications. The MEMS fabricated on a high resistivity silicon (HRS) substrate using surface micromachining technology. Simulation and experimental results reflection coefficients radiation patterns presented.

A flanged parallel-plate waveguide is used for the detection of a two-dimensional surface crack on metal plate. The Fourier transform and mode-matching technique are to obtain simultaneous equations, which solved represent characteristic signal. characteristics crack, such as position, width, depth, material in discussed terms

In this paper, the gain of single patch with superstrate is compared to that without and experimental results 2/spl times/8 array antenna superstrate, 4/spl are shown. Details proposed design presented.

To achieve efficient field formulations and fast numerical computations, the reciprocal relations equivalence between tangential normal boundary conditions for electromagnetic fields are discussed in terms of Maxwell's differential equations. Using each condition, we propose six essential conditions, which may be applicable to matching discontinuities efficiently design RF devices. In order verify our approach, reflection characteristics a rectangular waveguide step compared with respect conditions.

Arbitrarily polarized plane-wave difiraction equations for semi-inflnite periodic rectangular grooves (RG) in a perfectly conducting plane are approximately proposed. To obtain RG, we utilize an overlapping T-block method as proposed the analyses of flnite and inflnite numbers subtraction technique with solutions. The solutions then applied to RG very large number difiracting elements. For veriflcation our approach, performed numerical computations compared based on previously published...

A novel technique based on the Fourier transform is applied to analyze a ridge waveguide and rectangular coaxial line. On basis of image theorem line are transformed into guide with an infinite number grooves. The dispersion relations for obtained in rigorous, yet simple series forms. Numerical computations show that our solutions converge fast agree others.

Scattering solutions of an H-plane T-junction in a parallel-plate waveguide are investigated. The iterative procedure and Green's function relation used to obtain the equations for Ez field modal coefficients, thus resulting matrix solutions. scattering characteristics reflection transmission powers presented compared with other existing results.