The concept of distributedly modulated capacitors (DMC) is proposed as a form time-varying transmission-line structure offering nonreciprocal propagation and coupling characteristics. nonreciprocity achieved by taking advantage the additional dimension time-variance in property. complete theory, based on: 1) distributed parametric effect on transmission line 2) capacitive mixers, presented with emphasis theoretical bounds isolation insertion performances DMC. Simulations are carried out...

Pt nanoparticles play an essential role in a wide variety of catalytic reactions. The activity the particles strongly depends on their three-dimensional (3D) structure and exposed facets, as well reactive environment. High-resolution electron microscopy has often been used to characterize nanoparticle catalysts but unfortunately most observations so far have either performed vacuum and/or using conventional (2D) situ microscopy. latter however does not provide direct 3D morphological...

Abstract Achieving non-reciprocity through unconventional methods without the use of magnetic material has recently become a subject great interest. Towards this goal time switching strategy known as Sequentially-Switched Delay Line (SSDL) is proposed. The essential SSDL configuration consists six transmission lines equal length, along with five switches. Each switch turned on and off sequentially to distribute route propagating electromagnetic wave, allowing for simultaneous receiving...

A rising interest in entropy-stabilized oxides recent years has been driven by their attractive functional properties. Their synthesis usually requires prolonged exposure at high temperature to promote solid-state diffusion without the application of pressure. In this work, we report a entropy perovskite, Sr((Zr0.94Y0.06)0.2Sn0.2Ti0.2Hf0.2Mn0.2)O3−x, relatively short time (minutes instead hours) using spark plasma sintering (SPS) furnace. Comparative analysis showed that conventional...

A novel gate diode triggered silicon-controlled rectifier (GDTSCR) with dual-direction high-voltage (HV) electrostatic discharge (ESD) protection and a low snap-back voltage is proposed investigated. Compared to conventional MOS SCR (MTSCR), the GDTSCR has two diodes one additional n-p-n. Superior MTSCR, exhibits high holding of 15 V, small trigger 17 strong ESD robustness 6000 V in an area <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML"...

With the increasing demands of wireless communication and sensing such as mobile cellular networks Internet Things, radio spectrum is becoming a scarcer resource more than ever. The electromagnetic waves emitted from transmitter typically occupy certain information channel that divided into either time [e.g., division duplex (TDD)] or frequency [e.g. (FDD)], and, within this channel, all receivers sensors colocated with are normally paralyzed.

Verification of physical (PHY) layer and medium access control (MAC) procedures the fifth-generation (5G) specifications with real hardware prototypes is important in commercialization 5G mobile communication systems challenging as well. In this paper, we propose a flexible software-defined-radio (SDR)-based prototype design for user equipment (TIE), which can be used to implement novel concepts. The proposed architecture featured by using baseband signal processing module two independent...

Single and cascaded microstrip step discontinuity problems are studied. Modal formulations numerical solution procedures investigated in an effort to determine computationally efficient techniques for the of such problems. The enforcement a model orthogonality criterion, boundary enlargement/reduction concept, convergence as function number modes their accuracy considered. Theoretical experimental results presented scattering parameters several sample geometries.< <ETX...

Localized corrosion in AA2024‐T3 specimens was investigated by ex situ transmission electron microscopy (TEM) studies to determine an experimental window for real TEM studies. In the as‐prepared specimens, intermetallic phases leading local galvanic couples were classified based on size and composition. The behavior of two kinds corrosive environments, 1 M NaCl oxygen bubbled through aqueous HCl pH = 3. exposed a environment duration 30 min, remnant copper‐rich particles as result...

We have experimentally demonstrated a wavelength-tunable passively mode-locked all-fiber laser at 1.5 μm wavelength by using an erbium-doped fiber amplifier, fiber-pigtailed semiconductor saturable absorber mirror, and tunable birefringence Sagnac filter. In our work, properly setting the polarization state of propagating light in filter, lasing can be continuously tuned from 1544.1 to 1560.8 nm, corresponding tuning range 16.7 nm. At central 1548.5 delivers pulses as short 713.2 fs with...

In this paper, the problem of blind equalization high-order quadrature amplitude modulation (QAM) signals is tackled by using a batch equalizer based on support vector regression (SVR). Anew set error functions weighted neighborhood symbol decisions and augmented generalized power factors p q, are proposed to be used as penalty terms in SVR, optimal values q determined. addition, we propose method remove high online computational complexity incurred inclusion new function. Simulation results...

In this letter, ridge regression, which is a regularization method, explored for relaxing the requirements on number and maximum amplitude of training samples in digital predistortion. An effective method proposed to determine parameter, essential regression used regularize predistorter identification. Experiments demonstrate that required can be relaxed by 95% 30%, respectively, with tolerable linearization performance loss.

5G communication systems promise high data rates over Gbits/S and minimum delay in transfer. Millimeter wave band, due to its abundant spectrum that is available, considered be the key enabling technique for such links. However, propagation loss poor penetration through obstacles of electromagnetic waves at millimeter (mmWave) makes it difficult outdoor-to-indoor communication. On other hand, signals microwave band can easily penetrate buildings, but single channel capacity limited by narrow...

The thrust toward 5G communication has placed an increasing weight upon the performance bounds of current technologies. As number spectrum users continues to grow, need for efficient use spectral resources grows along with it. SSDL, which stands Sequentially-Switched Delay Lines, provides a solution this issue. SSDL concept is time-switching strategy, uses set switches and transmission lines simultaneously route transmitted received waveforms their respective ports over broad bandwidth. does...

Cooperative jamming is envisioned as a key technique to enhance the wireless secrecy. With help of cooperative node, confidential communications are ensured by emitting signal combat against eavesdropping. Concurrently, this also propagates into legitimate node through multipath channel, then becomes self-interference (SI). In letter, nonlinear SI cancellation scheme proposed jointly taking account frequency offset, power amplifier nonlinearity, and effect. These practical imperfections...

In the practice of terahertz upstream and downstream systems, inconsistency up/downstream channels frontends, unpredictable nonideality transceivers, crosstalk between lead to short communication range limits application scenarios systems. this article, an all-solid-state full-duplex systems working in 220 GHz band is proposed with a 630 m distance. Frequency division multiplexing orthogonal frequency are employed. Terahertz frontend real-time demodulation baseband circuit designed,...

In the communication mechanism of co-time co-frequency full-duplex (CCFD), digital self-interference cancellation (SIC) is used for suppressing residual (SI) after antenna and radio frequency (RF) SICs, as well low-power multipath SI. this study, CCFD LTE verification experiment presented, which adopts SIC with SI signal reconstructed in domain. For Rayleigh channel, expression capability derived relationship among channel estimation error, received power, analyzed. Experimental results show...

In full-duplex communication systems, reflections of transmitted waves as a result the antenna mismatch may leak into receiver and create strong on-site interferences. Such cannot be suppressed by conventional frontend isolation techniques even with ideal circulators. Indented arrays are thus proposed to destructively combine reflection from each element prevent them negatively impacting sensitivity. The essential idea is break symmetry between transmitting receiving paths using an aperture...

This paper presents a T/R isolation enhancement technique that takes advantage of the different phase delay characteristics paths in an indented antenna array. The purpose is to enhance from what offered by circulators as well overcome reflection power without limiting choices polarizations and radiation patterns. essential idea array offset element away broadside aperture so leakage signal each individual cancelled when combined. An eight-element designed co-simulated with feeding network...

An indented quasi-Yagi antenna array is proposed for the purpose of achieving better impedance match by creating and combining out-of-phase return losses from each individual element. The architecture, jointly with non-reciprocal components such as circulators, can provide higher isolation between transmitting receiving paths in a full-duplex radio, without limiting choices polarizations radiation patterns. four meandered dipole elements feeding network designed fabricated on Rogers 4350...