Two-channel Structures Research Articles

STRUCTURAL ANALYSIS OF ON-BOARD MULTIMODE AUTO TRACKING SYSTEM

Two variants of two-channel structures of tracking systems has been introduced into consideration, which are sequentially used in two modes of operation of the on-board automatic tracking system. Taking into account the fact of quantization according to the level of signals for measuring the angles of mismatch of each of the channels, it is justified to use not one, but two different structures in the second auto-tracking mode. Using mathematical modeling, the expediency of increasing the number of two-channel structures from two to three, used in a single auto-tracking process according to the criterion of the provided dynamic accuracy, have been demonstrated. This paper presents a two-channel structures investigation for tracking systems operating in tracking mode of maneuverable targets, taking into account various systems of carrier operations. Considered multichannel complex control system (CCS) structure that include precise channel (PC) and coarse channel (CC). CC use the carrier and the flight control system (FCS) to make rude tracking. The PC function implemented by an optoelectronic device (OED) has placed in a traditional angular mechanical suspension, which act with high accuracy. Described three CCS operation modes classified by target mark fall inside or outside direction finder (DF) CC or PC field of view. At the capture mode can be used only information from the CC DF. At the complex control mode becomes possible to use information from both CC DF and PC DF. At the precision mode, it is advisable to use information only from the PC DF. Developed CCS functioning math model to check main points of this work. Math model makes possible to carry out simulation tests for each mode in a separate operation, as well as when they are integrated into a single complex automatic target tracking mode. Has been described efficiency factor as the total time of satisfactory accuracy relative to entire experiment time. On math model modes efficiency has compared to each other. As result precision mode have higher efficiency and capture mode lowest. As conclusion recommended use a precision mode to achieve higher accuracy at auto tracking tasks.

Anti-clogging performance optimization for dentiform labyrinth emitters

It is of great scientific significance to reveal the flow characteristics of dentiform emitters and to optimize the channel structure of emitters to improve the anti-clogging properties of emitters, which contribute to improving the working performance of irrigation systems. The study was carried out using computational fluid dynamics (CFD) simulations, combined with the physical test in the laboratory. First, this paper analyzes the distributions of flow velocity, kinetic energy in turbulence, and physical particle trajectories inside the different structural emitters based on CFD simulations, and based on the simulation results, a dentiform emitter optimization scheme was proposed, and two-channel structures, including the structurally improved emitter, were arranged to conduct indoor tests for verification. The result shows that the maximum kinetic energy in turbulence in the flow channel appeared in the main flow area and that the area of strongest energy dissipation in turbulence was at the tooth tip. The main flow area was largest for the emitter with the triangular channel, and the turbulence energy of the low-speed region was highest for the circular trapezoidal structure. The results suggested a scheme for further optimization of the dentiform emitter. For the optimized channel structure, the maximum value of turbulent kinetic energy was increased by about 19–101% compared with the other four flow channels. The area of the main flow region and the kinetic energy in turbulence in the low-speed area in the emitter were increased. In addition, the range of kinetic energy in turbulence was increased by 52–200% in the low-speed region of the channel. The transport rate of physical particles was increased, and the transport distance and residence time of the particles were reduced. The physical test results show that the optimized channel structure emitter achieved a decrease in the clogging probability compared with the other four structures. Therefore, increasing the area of the main flow region and the low-speed area in the flow channel is an effective physical way of physically improving the anti-clogging performance of the emitter.

Scalable Bandwidth-Tunable Micro-Ring Filter Based on Multi-Channel-Spectrum Combination

We propose and experimentally demonstrate a scalable bandwidth-tunable bandpass filter on silicon. Its spectrum is combined by that of four channels and each channel is formed by two cascaded micro-ring resonators (MRRs). By tuning the center wavelength spacing of the eight MRRs and the phase shifts of four channels, a wide bandwidth tuning range from 37.5 GHz to 227.5 GHz can be achieved with a shape factor between 0.2 and 0.73 and an in-band ripple less than 1 dB. By comparing with the performance of three-channel and two-channel structures, we can draw the conclusion that inducing more channels can effectively improve the bandwidth tunability. The filter also has a wide free spectral range (about 1.2 THz) and small footprint (0.12 mm2).

Broadband mixing of {mathscr{P}}{mathscr{T}}-symmetric and {mathscr{P}}{mathscr{T}}-broken phases in photonic heterostructures with a one-dimensional loss/gain bilayer

Combining loss and gain components in one photonic heterostructure opens a new route to efficient manipulation by radiation, transmission, absorption, and scattering of electromagnetic waves. Therefore, loss/gain structures enabling {mathscr{P}}{mathscr{T}}-symmetric and {mathscr{P}}{mathscr{T}}-broken phases for eigenvalues have extensively been studied in the last decade. In particular, translation from one phase to another, which occurs at the critical point in the two-channel structures with one-dimensional loss/gain components, is often associated with one-way transmission. In this report, broadband mixing of the {mathscr{P}}{mathscr{T}}-symmetric and {mathscr{P}}{mathscr{T}}-broken phases for eigenvalues is theoretically demonstrated in heterostructures with four channels obtained by combining a one-dimensional loss/gain bilayer and one or two thin polarization-converting components (PCCs). The broadband phase mixing in the four-channel case is expected to yield advanced transmission and absorption regimes. Various configurations are analyzed, which are distinguished in symmetry properties and polarization conversion regime of PCCs. The conditions necessary for phase mixing are discussed. The simplest two-component configurations with broadband mixing are found, as well as the more complex three-component configurations wherein symmetric and broken sets are not yet mixed and appear in the neighbouring frequency ranges. Peculiarities of eigenvalue behaviour are considered for different permittivity ranges of loss/gain medium, i.e., from epsilon-near-zero to high-epsilon regime.

High transformer ratio of multi-channel dielectric wakefield structures

Dielectric wakefield (DWA) accelerator concepts are receiving attention on account of their promising performance, mechanical simplicity, and anticipated low cost. Interest in DWA physics directed toward an advanced high-gradient accelerator has been enhanced by a finding that some dielectrics can withstand very high fields (>1GV/m) for the short times during the passage of charged bunches along dielectric-lined channels. In a two-channel structure, a drive bunch train propagates in a first channel, and in the second adjacent channel where a high gradient wakefield develops, a witness bunch is accelerated. Compared with single-channel DWA׳s, a two-beam accelerator delivers a high transformer ratio, and thereby reduces the number of drive beam sections needed to achieve a given final test beam energy. An overview of multi-channel DWA structures will be given, with an emphasis on two-channel structures, presenting their advantages and drawbacks, and potential impact on the field. Studies aimed to examine charging rate and charge distribution in a thin walled dielectric wakefield accelerator from a passing charge bunch and the physics of conductivity and discharge phenomena in dielectric materials useful for such accelerator applications are presented in a separate paper in the EAAC-2015 conference proceedings.

Theoretical analysis of coherent perfect absorption in one-dimensional anti-laser

Detailed analyses and the correlations of coherent perfect absorption (CPA) in single-channel and two-channel structures are performed by the transfer matrix and scattering matrix method. The results show that there are many possibilities for single-channel and two-channel structures to satisfy the occurring of CPA. Moreover, with the same incident wavelength and refractive index of dielectric, the length of dielectric for two-channel CPA is twice that for single-channel. For instance, it is 3.701 m/7.402 m for single-/two-channel CPA as 756 nm wavelength is incident on Si material. Our results facilitate the application of CPA in optical modulator, switches, detector, etc., and they are also of significance for Si-based integration of optical circuits in optical communication and computer.