The mid-infrared spectra of large PAHs ranging from C54H18 to C130H28 are determined computationally using Density Functional Theory. Trends in the band positions and intensities as a function of PAH size, charge and geometry are discussed. Regarding the 3.3, 6.3 and 11.2 μm bands similar conclusions hold as with small PAHs. This does not hold for the other features. The larger PAH cations and ...

Photonic band-gap (PBG) crystals offer new dimensions of freedom in controlling propagation of electromagnetic waves. The existence of stop-bands in the transmission characteristic of these crystals makes them a suitable element for the realization of many useful microwave and optical subsystems. In this paper, we calculate the propagation constant of a one-dimensional (1-D) photonic crystal by...

Novel tetrachiral honeycomb structures are evaluated for the first time from the vibroacoustic point of view. A numerical method based on Bloch wave approximations for Finite Element models of the unit cells is applied to simulate the pass-stop band characteristics of these cellular solids. Experimental modal analysis and modal densities are measured on honeycomb panels and sandwich plate, and ...

In this paper, we present the smallest form factor microstrip-fed ultra-wideband antenna with quintuple rejection bands for use in wireless sensor networks, mobile handsets, and Internet of things (IoT). Five rejection bands have been achieved at the frequencies of 3.5, 4.5, 5.25, 5.7, and 8.2 GHz, inseminating four rectangular complementary split ring resonators (RCSRRs) on the radiating patch...

Fast and efficient spectrum sensing is vital for multiradio multi-channel cognitive radio (CR) networks where unlicensed secondary users (SUs) have to sense and opportunistically transmit on multiple spectrum bands without causing any harmful interference to the licensed primary users (PUs) of those spectrum bands. Accordingly, this paper presents a smart, practical and efficient wideband spect...

We investigate both experimentally and theoretically the waveguiding properties of a novel double trench waveguide where a conventional single-mode strip waveguide is embedded in a two dimensional photonic crystal (PhC) slab formed in silicon on insulator (SOI) wafers. We demonstrate that the bandwidth for relatively low-loss (50dB/cm) waveguiding is significantly expanded to 250nm covering alm...