In this letter, we report on the design, fabrication, measurement, and analysis of a tunable low-frequency broadband radar absorber applied in frequency range 1-12 GHz. Numerical simulations indicate that absorbers based resistor-loaded selective surface (FSS) can be resistively tuned to give absorption exceeding -10 dB between 1 12 Moreover, superior absorbing performance achieved by introducing capacitance paralleled with resistance. Measurement results show absorber, way configuration...

Frequency selective rasorber (FSR) is a special absorber with transmission window. Due to the characteristics of in-band and out-of-band absorption, FSR considered as candidate for stealth radome. By breaking through technical barrier traditional windows design, we implement double lossy layers first time in public reports. The configured by cascading two above lossless layer air spaces separate them. It has independent absorption bands, which are provided their layers, respectively....

At frequencies below 2 GHz, conventional microwave absorbers are limited in application by their thickness or narrow absorption bandwidth. In this paper, we propose and fabricate an ultra-thin broadband active frequency selective surface (AFSS) absorber with a stretching transformation (ST) pattern for use the ultrahigh-frequency (UHF) band. This is loaded resistors varactors to produce its tunability. To expand tunable bandwidth, applied ST various coefficients x y unit cell pattern. With...

A hedgehog-like hollow Ni-Mn precursor with uniform ordered 1D nanostructures is prepared by a facile directional Mn-induced approach. The oxides and sulfides are obtained after thermal treatment vulcanization for the studied retain morphology. excellent electrochemical performance of two products has promising potentials future energy storage systems.

In this article, a frequency-selective surface (FSS) rasorber based on four metallic FSS functional layers is proposed. The consists of two absorption layers, transmission and corresponding dielectric isolation layers. top layer third are applied to generate wide band at high frequency low frequency, respectively. second bottom adopted low-pass bandpass band, multilayer structure the guarantees great span, broad bandwidth, stable scattering characteristics. Moreover, we adopt equivalent...

A frequency-selective rasorber (FSR) with a high selectivity transmission passband and two absorption bands is proposed in this letter. The design method introduced based on the equivalent circuit model (ECM). This structure consists of lossy layer lossless layer. composed Jerusalem elements parallel resonance unit center, load resistors metal branch. integrated by multilayer frequency selective surface to realize wide band. current distributions loss density were illustrated explain working...

In ultra-high frequency (UHF) band, conventional microwave absorbers are limited in application by their thickness or weight. order to solve this problem, a novel double-sided and dual-tuned active selective surface (AFSS) absorber for the UHF band is designed implemented first time. The physical mechanism analyzed equivalent circuit method (ECM) current distribution. Non-coplanar bias circuits of p-i-n diodes varactors proposed achieved structure. Fano resonance introduced structure...

Currently, high-temperature ceramic-based microwave-absorbing composites face limitations such as a limited range of material systems and narrow effective absorption bandwidth, which hinder their further application in electromagnetic wave field under environments. Herein, guided by simulation, lightweight (1.61 g/cm3), ultra-broadband (32.45 GHz) (800 °C) meta-structure TiCxN1-x fibers/Si3N4 composite was prepared combining composition structural design with the quick gel casting process...

Abstract This paper presents a novel method for fabrication of honeycomb absorbers by assembling step cylindrical resistive films into the holes. The process begins creating conductive film through screen printing. Next, this is wrapped around foam to form resistive. Finally, integrated structures, resulting in honeycomb-integrated microwave absorber with film. Excellent impedance matching and low reflection are achieved controlling square resistance provide transition between air metal...

Abstract A theoretical study was carried out by first‐principles calculations using plane‐wave pseudopotential method to investigate the crystal structures, relative stabilities, and elastic properties of seven known titanium dioxide (TiO 2 ) polymorphs. Our calculated equilibrium structural parameters TiO polymorphs are in good agreement with experimental results. Firstly, it is worth note that from our energy‐minimized generalized gradient approximation (GGA) calculations, four phases –...

A flexible design of a wideband double-layer microwave absorber is proposed. In order to break through the limitation single-layer absorbers at finite resonant frequencies, special double-layered structure adopted. The middle layer functional frequency selective surface core absorber. It exhibits two functions, which are or lossy in low and strong reflective high frequency. As result, coupling between layers weak, this feature leads having different absorption bands provided by (named as...

A convenient fabrication process about the ultrathin broadband composite microwave absorption material (MAM), which involves a frequency selective surface (FSS) sandwiched between two different magnetic sheets, is presented in this letter. The FSS consists of an array elements with geometry square-loop having split each edge (denoted as edge-split FSS). top and bottom sheets were prepared based on silicon rubber filled sphere-shaped flake-shaped carbonyl iron powders, respectively. It...

A method for designing and fabricating a dual-section step-impedance frequency selective surface (DSSI-FSS) absorber oblique incidence applications is proposed. The features of are realized by using two dielectric layers, which show better impedance matching characteristics compared with single-section layer. We also propose transmission line model that can be used DSSI-FSS at different angles. especially helpful the rapid design broadband wide-angle absorbers. proposed structure has −10 dB...

In this article, a patterned honeycomb absorber (PHA) with an embedded frequency-selective surface (FSS) was proposed for broadband applications. The impedance of the FSS in homogeneous (HA) first analyzed, which suggested that directly combining HA unreliable. Subsequently, PHA developed to adjust input impedance. Using PHA, structure wide absorption band developed. consistency between simulated and measured results verifies analysis design principle. may be very suitable various microwave...

An adjustable polarization-independent electromagnetic absorber based on a frequency-selective surface is proposed for both C and X microwave-band applications. The design using symmetric fan-shaped pattern significantly reduces the sensitivity to different polarizations of normal incident microwaves. To achieve adjustability, PIN diodes are connected between patterned unit cells. By incorporating inductors into metal patterns, an S-shaped series bias provides voltage diodes. tuning working...

The design, fabrication, and measurement of a metamaterial with broadband microwave absorption properties in the low frequency range are presented this paper. has layered structure thickness 2.2 mm, consists conventional printed circuit board (PCB) process fabricated cross array on surface flake-shaped carbonyl iron (CI) powder-filled silicon rubber composite magnetic substrate backed by metal plane. results indicate that bandwidth (defined as reflection coefficient below −10 dB) proposed is...

In this letter, a kind of composite radar absorption material consisting gradient and spiral square resistor frequency selective surface (FSS) magnetic sheets is designed by HFSS. The use FSS makes significant increase operating bandwidth compared to single materials (mRAMs). Under the condition normal incident electromagnetic wave, it has remarkable absorptive performance with reflectivity below -10 dB thin thickness 2 mm in range 6-18 GHz. addition, mRAMs exhibits high angular stability...

In this paper, we demonstrate a multimode and broadband absorber that is fabricated directly on PET substrate using commercial direct-to-garment (DTG) inkjet printer. A design procedure of kind presented. Based the theory characteristic mode, underlying modal behaviors structure are firstly analyzed to guide absorber. Two modes designed resonate around 1.83 GHz 4.28 cover working frequency range. Simulation measurement results show with total thickness 0.0883λL at lowest operating can...

Abstract A multisection step-impedance honeycomb absorbing structure is investigated both theoretically and experimentally. Excellent intrinsic impedance matching low reflection are realized by providing a transition between air metal in the microwave band. The wideband absorption mechanism of analyzed using model, particle swarm optimization algorithm used to obtain optimal step impedance. Two structures were simulated: double-layer had an frequency band 3.9–12.4 GHz thickness 9 mm,...