This study concerns the in‐motion alignment in strapdown inertial navigation system (SINS) with large misalignment angles. As non‐linear filtering method applied model is quite computer intensive, which has a significant impact on accuracy and speed. To solve this problem, robust H‐infinity cubature Kalman filter (CKF)/KF hybrid (RHCHF) proposed to lower computational burden strengthen robustness. By virtue of idea decomposition, RHCHF could estimate linear parts model, respectively. Through...

Accurate analysis of electromagnetic problems including inhomogeneous or anisotropic structures requires solving volume integral equations (VIEs) in the integral-equation approach. When are electrically large dimensions constitutively complicated materials, fast numerical algorithms desirable to accelerate solution process. Traditionally, such solvers developed based on method moments (MoM) with divergence-conforming Schaubert-Wilton-Glisson basis function curl-conforming edge function, but...

Converter transformer is the key important equipment in HVDC transmission system, and its life span depends heavily on insulation design. subjected to several types of voltage during factory testing operation, including AC, DC, combined AC-DC polarity reversal voltage, which makes systems converter significantly differs from AC transformer. Design major system realized through analysis electric field distribution with FEA software at critical locations a Three stresses should be analyzed...

A hybrid inversion approach based on the quantum-behaved particle swarm optimization (QPSO) method is presented in this article to solve electromagnetic inverse problems. Inverse scattering problems are ill-posed and often transformed into by defining a suitable cost function, which can be minimized evolutionary algorithms. This aimed at assessing effectiveness of customized QPSO reconstructing 2-D dielectric scatterers. The bottleneck that restricts application algorithm large-scale its...

The THz frequency band offers an exceptionally wide bandwidth, making it ideal for ultra-high-data-rate communication using simple modulation schemes like amplitude-shift-keying (ASK) [1–5]. By avoiding complex schemes, we can simplify the system architecture, reducing complexity of analog mixed-signal processing components, including high-speed multi-bit ADCs and DACs, which tend to be power-hungry area-consuming. However, challenges arise due amplitude nonlinearity, significantly reduce...

A low radar cross section (RCS) planar antenna using phase gradient metasurface is proposed in this paper. The works the X-band and fed by a parallel plate waveguide power divider. designed coplanar with feeding structure couples guided waves divider to radiation waves. According generalized reflection law, frequency scanning beam direction can be steered slightly from 16.6° 13°. linearly polarized, however, RCS reduced significantly for arbitrary polarized incident was simulated,...

Directional modulation (DM) is a physical layer security technology based on the multiantenna structure. Similar to traditional transmitters, DM transmitter also faced with problem of high peak-to-average power ratio (PAPR) and nonlinear distortion. The existing peak clipping methods for crest factor reduction (CFR) are not suitable transmitter. This letter proposes two-step (TPC) scheme specifically decrease signals' PAPRs presents highly efficient digital predistortion (DPD). Using 16-QAM...

We have demonstrated a frequency multiplier-based multiplying transmitter (MT) architecture, which shows the transmission of wideband modulated signals from lower band to millimeter-wave (mm-wave) through multiplier directly is viable option. To compensate for severe nonlinear distortions exhibited by in more efficient way, two-stage cascaded digital predistortion (DPD) scheme with constrained feedback bandwidth proposed. The complexity-reduced generalized memory polynomial (GMP) and...

Valve side lead exit is a key important part of converter transformer, by which bushing terminal connects with the transformer valve winding. consists and surrounding barrier system, it usually installed in ascending flange where resin impregnated paper (RIP), oil (OIP) co-exist compact place. So insulation requires focused analysis design stage. It not only withstands AC voltage, but also DC polarity reversal voltage during factory testing operation. In this paper, to ensure reliability...

A novel method is proposed for measuring the frequency response of photodiodes. This calculates photodiode based on gain peaks phase-modulated interferometric detection using a microwave network analyzer, and half-wave voltage phase modulator, which calibrated by intensity ratio modulated optical side-bands with spectrum analyzer. The experimental results show good match between measured Mach-Zehnder intensity-modulated direct demodulation, as well data provided manufacturer. It provides an...

A large power rectenna array has been designed and tested in S-band for applications involving microwave wireless transmission(WPT). The consists of a 16-element antenna rectifier based on GaAs. structure is printed F4B-2 substrate with the dielectric constant 2.55 thickness 1mm. Conventional rectifying circuits use schottky diode as chip,but output DC single circuit still stays mW levels. In this paper, theoretical analysis theory, efficient using GaAs transistors chip designed....

To image dielectric objects by integral equation approach, the forward scattering (FSIE) and inverse (ISIE) are alternatively solved in an iterative scheme. For solving FSIE, we propose a meshless method that changes volume integrals into boundary based on Green-Gauss theorem. The uses set of discrete points without connection to describe domain, yielding much convenience discretizing imaging domain. In addition, transformation can greatly simplify numerical solution FSIE allow initial guess...

In general, the carrier phase of orthogonal frequency division multiplexing (OFDM) signals is not tracked for at least two reasons. First, dc component most baseband OFDM symbols a null subcarrier so as to avoid effect bias reception. Second, generation and transmission are independent from one symbol next. As result, no continuity required be maintained any subcarriers. For communications, demodulation with cyclic prefix (CP) tolerant small timing errors insensitive absolute but relative...

A novel method for measuring modal power distribution (MPD) in multimode fibers is proposed using built-in tilted fiber Bragg gratings (TFBGs). For each degenerated guided mode group, a portion of the can be coupled to corresponding radiation through TFBG imprinted into same fiber, and then measured separately with spatial filter. The coupling coefficients between modes are obtained by solving set linearly independent equations acquired under number launching conditions. With these obtained,...

A nonresonant structure composed of metal cut-wires for realization metamaterials is proposed. This kind metamaterial works at an ultra broad bandwidth with uniform permittivity. Theoretical analysis and numerical simulations are carried out to study this inclusion expression the effective permittivity given. Several methods studied enhance a ultra-high obtained. demonstration shows that can be as high 145.

Abstract Low biasing technique has been used recently to reduce the relative intensity noise of microwave optical fiber links.In this article, possibility reducing phase opto‐electronic oscillator (OEO) by using low‐biased link is verified. Theoretical and experimental results show that single sideband (SSB) OEO can be reduced at maximum 2.8 dB in links when compared with conventional quadrature‐biased links. The optimal angle corresponding minimum SSB increases power into modulator. © 2012...

Electromagnetic analysis with $S$ -parameter characteristic is carried out for a tunable bandpass filter magnetodielectric perturber controlled by piezoelectric transducer. The consists of hairpin-like microstrip resonator and as superstrate, which composed thin ferrite film high permeability Rogers dielectric material permittivity in sandwich style. structure multiscale feature because the thickness very small but cannot be ignored also multimaterial property there are three strongly...

This paper proposes a frequency-doubling optoelectronic oscillator employing novel three-arm dual-output Mach-Zehnder modulator (MZM). One output of the MZM generates fundamental-frequency signal which is recycled by microwave optical fiber link for oscillation, and other can generate frequency-doubled signal. Experiment was conducted using commercial two-arm MZM, phase modulator, an 89 meters in length. A 19-GHz successively obtained with fundamental suppression more than 36 dB.

Time-domain analysis for transient electromagnetic scattering from dielectric objects is formulated through time-domain electric field integral equations (TDEFIEs). The TDEFIEs are usually solved by combining the method of moments (MoM) in space domain and march-on-in-time (MoT) scheme time domain. In space-domain MoM, current density represented with Rao-WiltonGlisson (RWG) basis function, while magnetic expanded n̂×RWG which may not be good, since it divergenceor curl-conforming. Also, MoT...

High-speed, high power-handling photodiodes with sufficiently low amplitude-to-phase (AM-to-PM) conversion coefficients are critical components in the systems that generate ultra-stable microwave signals. This paper reports AM-to-PM modified uni-traveling carrier (MUTC-PDs) 20 µm and 40 diameters. The contributions of conversions from transit-time impedance were quantified systematically based on a photocurrent-dependent nonlinear equivalent circuit model. It is found PD dominated by...