We investigated the measurement techniques of nonlinear vector network analyzer (NVNA) test bench, to fully characterize behavior radio frequency (RF) power amplifiers (PAs) driven by complex modulated signals. In order extend baseband measurements, two kinds NVNA phase reference approaches are developed as alternative solutions, so that measurements can be achieved with those components at multiharmonic RF bands. first approach, a signal is combined another one become desired reference....

This study considers the target identification problem for linear frequency modulation (LFM) radars interfered by smart noise, which is a newly proposed active jamming pattern much effective against LFM radars. An adaptive suppression algorithm utilizing atomic decomposition method. The means of establishing appropriate atoms dictionary firstly provided according to characteristics analysis dense false targets formed signal. return and noise are then decomposed as different atoms. Finally,...

Spraying a coating on the surface of wet parts solid-liquid two-phase flow centrifugal pump could effectively increase its service life.To research effect thickness performance pump, with speed n s = 81.5 was chosen, and polyurethane coatings different thicknesses were sprayed blades impeller.The influence tested under condition water medium.Combined numerical simulation, internal flow, pressure fluctuations radial force model further analysed in detail.Keeping blade outlet angle unchanged,...

A high energy 3.75 μm nano-second KTiOAsO4 (KTA) optical parametric oscillator (OPO) at a critical angle is demonstrated in this letter. The OPO pumped by 1.064 laser and the KTA crystal cut 41.2° XZ plane. phase matching edge of match curve absorption region for mid-infrared lasers. cavity signal resonant oscillator. spatial distribution pump light quasi-plane wave pulse width 10 ns. 218 mJ 1.484 60 idler are achieved with 795 mJ, corresponding to conversion efficiency 35%. 7 divergence...

In this article, a nonlinear vector network analyzer (NVNA) measurement setup is developed to characterize frequency modulated continuous wave (FMCW) signals in the domain. Thanks use of precisely synchronized multisine phase reference and pulsed-RF calibration standards, such NVNA validated for high-accuracy wideband FMCW at millimeter-wave test bands. According method validation 24 60 GHz with maximum bandwidth 2 GHz, proposed has lower errors uncertainties than commercial real-time...

In this article, we present a vector network analyzer (VNA)-based measurement scheme and setup to obtain repeatable phase spectrum measurements of 75–110-GHz modulated radio frequency (RF) signals. order remove the random contribution sweeping local oscillator (LO) in harmonic downconversion, LO signal is coupled out into an auxiliary channel where its at fundamental can be derived after additional modulation downconversion treatments. Afterward, user-defined math equation used inside VNA...

In this article, we present a novel nonlinear vector network analyzer (NVNA) setup for charactering the in-band full-duplex (IBFD) performance of millimeter-wave antenna systems. To achieve modulated measurements on dense spectral grids, NVNA utilizes user-defined: 1) digitally-modulated test stimuli; 2) multisine phase reference; and 3) pulsed-radio frequency (RF) calibration standards bench establishment calibration. create IBFD scenario, special design stimuli is developed...

In this study, reverberation chamber (RC) was used as a wireless channel simulator root mean square delay spread (RMS-DS) between antennas adjusted through applying different loadings. Based on the measurement and theoretical analysis, an approximate close-form solution has been developed to explain quantitative relationship RMS parameters of loading. This proved be valid in loading conditions with wider frequency band.

Abstract Copper, as one of the most hazardous metals to transformer insulation systems, has attracted a great deal interest from scholars at home and abroad. Unfortunately, specific type copper that causes catalytic aging oil-paper is still controversial. Therefore, in this paper, effect electronic state evolution different oxidation states on performance systems was investigated by characterization techniques evaluation. Cu 2 O stronger oxidizing system than CuO. This study elucidates its...

In this paper, we present a novel Nonlinear Vector Network Analyzer (NVNA) setup for generating and measuring digital modulation signal at millimeter-wave test bands. The first difference between commercial NVNAs is the use of user-defined multisine as phase reference, in order to enable more precise synchronization denser spectral grid. To achieve this, single 12.S-GHz microwave source used both 64-QAM which not only triggers arbitrary waveform generator intermediate frequency (IF)...

In this paper, we investigate the signal processing method of time-base correction for a sampling oscilloscope, so that eye diagram high-speed digital can be accurately characterized under different measurement modes. To achieve precise synchronization, single 12-GHz microwave reference is used not only as clock pattern generator generating pseudo-random binary sequence (PRBS), but also to provide two quadrature sinusoidal waves needed by oscilloscope correction. mode, free-run trigger...

The communication between the satellites and terminals on ground can profit from significant research achievements in area of terrestrial MIMO technology. In this paper, a novel linear prediction based FIR channel estimator is proposed to estimate outdated CSI introduced by long distance on-ground effectively. spatial correlation property temporal land mobile satellite model are investigated firstly. During process design, MMSE criterion adopted ensure its feasibility. After that, minimum...

In this paper, we investigate the precoder design for MIMO multicasting, where two data streams are sent from transmitter and minimum mean-squared-error decision feedback equalizer is performed at all users. To improve receiving quality of streams, focus on maximizing minimal signal-to-interference-plus-noise ratio (SINR) via precoding. Considering that composed a transformation matrix rotation matrix, separate into stages. Firstly calculate under criterion throughput multicast channel....

Broadband wireless channels are frequency selective in nature. In this paper, a novel precoder with finite impulse response (FIR) structure is proposed to maximize the throughput of multiple-input multiple-output (MIMO) frequency-selective multicast channel. An iteration mechanism investigated obtain desired FIR precoding matrix. iterative process, two associated parameters, namely innovation orientation and step size, jointly derived by convex optimization program traditional Gauss-Newton...

Finite impulse response (FIR) precoders are efficient precoding framework for frequency-selective multiple-input multiple-output (MIMO) channels. In this paper, the optimal linear FIR precoder is investigated to maximize capacity of MIMO channel under average transmit power constraint. We use Kronecker product regenerate nonconvex optimization problem and propose a semidefinite programming (SDP) relaxation scheme with Gaussian randomization provide approximate solutions. Numerical results...

In next-generation wireless communication systems, multimedia multicast could improve spectrum efficiency markedly. this paper, a angle-based limited feedback model is built for downlink multi-group systems. Two parts of the channel state information (CSI), i.e., quantized direction (CDI) and accurate quality (CQI) are fed back to base station (BS) simultaneously, where proper codebook shared by all users in system BS. With imperfect CSI available at BS, Quality Service (QoS) problem systems...

This paper proposes a measurement strategy to remove the random contributions of local oscillator (LO) phases from multi-tone radio frequency (RF) phase measurements based on down-conversion, so that stable spectrum result can be obtained for each run tone-by-tone sweeping measurement. To achieve this, LO used down-conversion is coupled out an extra path, and modulated become wideband multisine signal. For sweep, baseband modulating signal unaltered, hence multi-sine are only changed by...

In this paper, we present a vector network analyzer (VNA) based measurement scheme and setup to obtain repeatable phase spectrum measurements of millimeter-wave modulated signals. order remove the random contribution sweeping local oscillator (LO) in harmonic down-conversion, LO signal is coupled out into second channel where its at fundamental can be derived after additional modulation down-conversion treatments. The key point proposed cancellation technique measuring test LO-channel same...