Beam scanning antenna brings new opportunities to reduce the data collision of multinode communication in Internet Things (IoT). This article proposes a type design scheme that can be used for IoT relay communication. A programmable beam without phase shifters operating X-band is designed evaluate feasibility this scheme. The integrated excitation source and phase-modulated structure greatly reduces profile improves degrees freedom with other equipment. By switching state PIN diode loaded on...

With the small sampling length, a novel Direction-of-Arrival (DOA) estimation method based on single programmable metasurface sensor is proposed in this article. Serving as physical random receiver, dynamic generates series of radiation patterns to sense incident signals, which subsequently processed by compressive sensing (CS) orthogonal matching pursuit (OMP) algorithm recover DOA information. A mathematical model first built for theoretical analyses. Furthermore, numerical simulations are...

This article presents a high-selectivity frequency-selective rasorber (FSR) with an adjustable out-band absorptivity property. is composed of dynamic absorptive surface (AFSS) on the top, p-i-n diodes employed to achieve tunable absorptivity, and high-quality ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> )-factor bandpass FSS in bottom, aperture-coupled resonators (ACRs)...

Radiating twisted beams, orbital angular momentum (OAM) based radar provides a new perspective for present techniques. However, estimation methods now used has demerit of resolution. Thus, we raised multiple signal classification (MUSIC) algorithm to improve resolution ability on this innovative concept. The echo model uniform circular array MUSIC was first built. In contrast uncorrelated signals in classical algorithm, from targets are fully coherent with each other. Spatial smoothing...

Uniform circular array (UCA) is a pioneering approach to generate radio twisted beams carrying orbital angular momentum (OAM). However, faulty antenna elements in UCA could render the into an imperfect (IUCA), consequently creating distortion for OAM-based communication or radar systems. To analyze effects of IUCA on generating OAM, elementary wave function and transformation are derived obtain field equations general array. Further derivation shows that superposition OAM modes, which caused...

This paper presents an energy selective surface (ESS) for high-power microwave (HPM) protection in waveguide, which has a nonlinear transmission response and can adaptively react to the power intensity of incident wave. A prototype four unit cells loaded with p-i-n diodes is designed fabricated L -band. The adaptive characteristics are demonstrated by waveguide measurements both time domain frequency domain. On condition signal below 35 dBm, wave interested band propagate through low...

A novel single-layer substrate integrated waveguide (SIW) corrugated technique, consisting of an SIW slot and two grooves, is proposed in this letter, based on which high-gain low-mutual-coupling Ka-band multiple-input-multiple-output (MIMO) antennas are demonstrated. The mechanism gain enhancement basic element elaborated first before the analyses MIMO antennas. simulated measured results show that elements 1 2 have average 1.6 GHz (5.8%) bandwidth from around 26.8 to 28.4 GHz, gains can be...

A terahertz metamaterial with switching characteristics from optical buffering to absorbing performance is realized by incorporating a phase-change film of vanadium dioxide. By introducing the electromagnetically induced transparency behavior based on simple strip pairs, slow light effect group delay up 3.5 ps obtained. When dioxide in insulator state, remarkable can be observed as incident pulse transmits through designed structure. Once tuned metallic switched absorber and maximum...

In this paper, a new type of terahertz (THz) metamaterial (MM) modulator has been presented with bifunctional properties based on vanadium dioxide (VO2). The design consists VO2 resonator, polyimide substrate, frequency selective surface (FSS) layer, and film. Based the metal-insulator transition (MIT) VO2, structure integrated material can achieve dynamic modulation both transmission reflection waves at 2.5 THz by varying electrical conductivity value VO2. Meanwhile, it also exhibits...

Field-induced nonlinear materials, with extended abilities of manipulating electromagnetic waves, have been widely employed in protection, absorption, and detection. Until now, it was found that the field-induced nonlinearity mainly shows optical terahertz frequency bands. Applying microwave band into such technical activities is hampered due to a lack investigations on caused by electric fields, especially ultrawideband high-frequency In this paper, metamaterial (NLMM) concept based...

A novel design method for ultra-broadband energy selective surface (ESS) is presented in this article based on the equivalent theory from filter circuits to metamaterial units. This provides a new way of designing ESS with low insertion loss (IL) and high shielding efficiency perspective circuit topology. It illustrated verified three layer ESS. Firstly, third-order switching bandpass bandstop C Ku-band designed optimized. Then, mapped physical model three-layer which has nonlinear...

In this article, a PIN-diode-based high-intensity radiation fields (HIRF) protection method was proposed and the sensitivity to field intensity of incident wave has been verified by printed dipole antenna loaded with three pairs PIN diodes at S-band. To illustrate method, an equivalent linear circuit raised analyze basic operation principle antenna. With low-power wave, are in off-state gain remains unaffected; while it drops considerably as triggered HIRF. Furthermore, extensive parametric...

Without any relative moves or beam scanning, the novel Orbital-Angular-Momentum- (OAM-) based radar targets detection technique using uniform concentric circular arrays (UCCAs) shows azimuthal estimation ability, which provides new perspective for system design. However, main method, that is, Fast Fourier Transform (FFT), under this scheme suffers from low resolution. As a solution, paper rebuilds OAM-based model and introduces multiple signal classification (MUSIC) algorithm to improve...

A high-efficiency reconfigurable element for dynamic metasurface antennas (DMA), consisting of a complimentary electric-LC (CELC) resonator fed through the cavity from waveguide slot, is proposed in this paper, with positive- intrinsic-negative (PIN) diodes loaded to realize coding performance. To begin with, low efficiency problem traditional CELC demonstrated before introduction element. Subsequently, an equivalent circuit illustrated analyse resonant performance, extensive parametric...

This letter proposes a frequency selective rasorber (FSR), whose transmission and absorption bands can be controlled independently by the Schottky barrier diode (SBD) stepper motor, respectively. The FSR is composed of resistive sheet, switchable bandpass surface (FSS), four motors. band switched to stopband with SBD turned on. And location adjusted Both simulated measured results show that do not affect each other.

In this paper, a novel mode composite waveguide based on hybrid substrate integrated and spoof surface plasmon polariton (SIW-SSPP) is proposed. Through different feeding methods, the odd even of SSPP are excited simultaneously operate at same frequency band. Thus, co-frequency multiplexing achieved for proposed odd-even (OEMCW). The design principle characteristics OEMCW analyzed in work. A prototype fabricated measured to demonstrate its transmission performance. results indicate that can...

Flexible metamaterial absorber manufactured with a layer-by-layer screen-overprinting methodology has been theoretically and experimentally studied in this letter. The effective absorption of the is X-band (8.3-10.9 GHz) its working principle verified analyzed. Benefiting from elimination parasitic effect brought by package-free direct-contacted planar resistors, high agreement between simulations measurements achieved. frequency band can be easily tuned replacing different supporting...

This article presents an adaptive high-impedance surface (A-HIS) that can be applied in the prevention of high-intensity wave propagating <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula> -band waveguide. Once embedded diodes loaded on A-HIS are switched from OFF- to ON-states by incident wave, boundary condition waveguide's bottom wall would adaptively change a perfect...

It remains a typical engineering problem demanding prompt solution to measure the electromagnetic radiation of equipments accurately in complicated environment. A new measurement method for ambient interferences suppression an situ radiated emission test is proposed. Technologies signal processing such as side lobe cancellation and frequency section have been adopted filter background smart way. The effects on different kinds are studied. simulation results show that can simultaneously...

This paper presents a waveguide energy-selection-filter switch (ESFS) array for high-power microwave protection, which has nonlinear transmission response depending on the power intensity of incident wave.A prototype nine unit-cells loaded with pin diodes is designed and measured.First, relationship between unit-cell dimension frequency analyzed by full-wave simulation, an equivalent circuit studied numerical fitting.Then, non-linear characteristics different levels are observed using...

In this paper we address a novel method of eliminating ambiguity for planar array. It is known that appears in the direction arrivals (DOA) estimation when aperture array large enough. We propose rotating to solve problem. Firstly, use multiple signal classical algorithm (MUSIC) estimate DOA. Then rotate an angle and MUSIC again obtain spatial spectrum. Later, rotary (R-MUSIC) defined as root two spectrums product proposed, which can suppress pseudo peaks Furthermore, Improved R-MUSIC...

An improved substrate integrated waveguide corrugated technique with grounded coplanar (GCPW) transition is presented in this letter, based on which three antennas are designed and tested. Compared to our previous antenna, more bandwidth higher gain can be achieved the first design. Probes at slot grooves used monitor in-phase responses, provide guidance for an efficient parameter optimization. Subsequently, a further minor enhancement second design, employs two neighboring each side. A...

A novel Energy Selective Filter (ESF) mounted in waveguide is presented based on nonlinear element, which sensitive to the power intensity of incident wave achieving frequency selection as well energy selection. The proposed ESF consists three parts, middle circuit board with diode loaded, upper and bottom ground metallic patches. mechanism analyzed through equivalent model its performance investigated numerically experimentally. According measurement, a shielding effectiveness 13 dB...