Search

For analysing the oblique incident plane wave on periodic structures, an unconditionally stable finite-difference time-domain technique is presented to improve the split-field method. By splitting only one field component, the transformed Maxwell's equations can be subdivided into two sub-steps using the alternating-direction-implicit scheme. The accuracy and efficiency of the proposed method is verified by comparing with the original split-field method. [ABSTRACT FROM AUTHOR]

A perfectly matched layer (PML) implementation for the unconditionally stable Laguerre based BOR-FDTD is presented. To validate the presented method, the scattering from a PEC cylinder is calculated. Compared with Mur's absorbing boundary, the presented PML shows better absorbing performance. [ABSTRACT FROM AUTHOR]

A frequency doubling approach for optical generation of tunable microwave and millimetre-wave signals is proposed and verified experimentally. The experimental setup is based on an optical phase modulator and a simple uniform fibre Bragg grating. The generated signal is of high quality and can be tuned. [ABSTRACT FROM AUTHOR]

Demonstrates a novel broadband multichannel polarization-insensitive wavelength converter in a periodically poled MgO-doped LiNbO3 waveguide and with two pump waves advantageously located out of the signal band. Cascaded frequency generation and difference frequency generation.

A reconfigurable band-notched ultra-wideband antenna is proposed. The antenna mainly consists of a modified rectangle radiating element, a staircase ground plane and two simple pin diode switches, and its entire size is 33.0×28.0×1.0mm. The presented antenna has nearly omnidirectional patterns, stable gain, small group delay and an available impedance bandwidth ranging from 3.1 to 12.5 GHz, including dual band-notched bands centred at 3.5 and 5.5 GHz, respectively. By reconfiguring the states of pin diode switches, the dual notched bands can be reconfigurable. That is to say, the reconfigurable antenna is able to switch among four operative modes (none or 3.5GHz or 5.5GHz or dual band-rejected). [ABSTRACT FROM AUTHOR]

The near-infrared quantum efficiency of pin photodetectors based on a lattice-matched type-II InGaAs/GaAsSb absorption region has been measured. The quantum efficiencies for these devices are 80.2 and 57.8% at 1064 and 1550 nm, respectively. These results are comparable to the more commonly-used InGaAs/InP photodetectors. [ABSTRACT FROM AUTHOR]

Recently, an adaptive generalised likelihood ratio test-linear quadratic (AGLRT_LQ) detector has been proposed for MIMO radar in the presence of non-homogeneous clutter. However, this method suffers a large performance loss when the amount of secondary data available is small. In this reported work, a full data GLRT detector is derived by utilising not only the primary data but also the secondary data in the design process and the covariance matrix estimation process to decrease this loss. [ABSTRACT FROM AUTHOR]

An anisotropic-medium perfectly matched layer (PML) for efficient Laguerre-based finite-difference time-domain (FDTD) method is presented. To verify the validity of the presented method, a numerical example of scattering from a two-dimensional rectangular conductor is given. Compared with Mur's absorbing boundary condition, the presented PML shows better absorbing performance. [ABSTRACT FROM AUTHOR]

A temporal error concealment technique referred to as the selective motion field interpolation is investigated. Simulation was conducted on the H.263 codec and experimental results show that the proposed method significantly outperforms other concealment techniques. [ABSTRACT FROM AUTHOR]

For analysing the 3D periodic structures at the oblique incident, a weakly conditionally stable finite-difference time-domain method is proposed by applying the Crank-Nicolson (CN) scheme to the field transformation technique. By splitting the space operator matrix in a special way, the transformed Maxwell's equations can be subdivided into two sub-steps for an efficient implementation. The proposed method does not need to introduce additional field components to handle the extra time terms and the time step size is only determined by one space discretisation. [ABSTRACT FROM AUTHOR]

Dual-band filtiers are common in dual-band transceivers, to attenuate interfering signals, and transmit the main signal in the desired passband. Reported is a compact low-temperature co-fired ceramic (LTCC) dual-band filter, constructed with a vertically folded structure and stepped-impedance stubs. The novel vertical interconnection scheme with its multilayered structure reduces the area of the filter by half. A 2.4/5.8 GHz dual-band experimental filter has been designed and assembled to verify the proposed design concept. S-parameter test results demonstrated good agreement between simulation and measurement. [ABSTRACT FROM AUTHOR]

A novel scheme using Brillouin optical time-domain reflectometry (BOTDR) and a fibre Bragg grating (FBG) sensor array simultaneously for long distance strain monitoring and accurate strain measurement of some key position is presented. BOTDR and FBG sensing parts are integrated into one system and a strain experiment is carried out. Experimental results show that the whole sensing system can work simultaneously without reference and achieve a strain distribution measurement as well as the point to point precise strain detection along a 20 km sensing fibre. The strain resolution of the system is 50 µℇ for BOTDR and 1 µℇ for FBG, respectively, along 20 km distance, while a spatial resolution of 2 m can be achieved for the BOTDR part. [ABSTRACT FROM AUTHOR]