Single-Port Coherent Perfect Loss in a Photonic Crystal Nanobeam Resonator

We numerically demonstrated single-port coherent perfect loss (CPL) with a Fabry–Perot resonator in a photonic crystal (PC) nanobeam by using a perfect magnetic conductor (PMC)-like boundary. The CPL mode with even symmetry can be reduced to a single-port CPL when a PMC boundary is applied. The boundary which acts like a PMC boundary, here known as a PMC-like boundary, and can be realized by adjusting the phase shift of the reflection from the PC when the wavelength of the light is within the photonic bandgap wavelength range. We designed and optimized simple Fabry–Perot resonator and coupler in nanobeam to get the PMC-like boundary. To satisfy the loss condition in CPL, we controlled the coupling loss in the resonator by modifying the lattice constant of the PC used for coupling. By optimizing the coupling loss, we achieved zero reflection (CPL) in a single port with a PMC-like boundary.

Modified Theory of Physical Optics Approach to Diffraction by an Interface between PEMC and Absorbing Half-Planes

The scattering of electromagnetic plane waves by an interface, located between perfect electromagnetic conductor and absorbing half-planes is investigated. The perfect electromagnetic conductor half-plane is divided into perfect electric conductor and perfect magnetic conductor half-screens. The same decomposition is done for the absorbing surface. Then four separate geometries are defined according to this approach. The scattered fields by the four sub-problems are obtained with the aid of the modified theory of physical optics. The resultant scattering integrals are combined in a single expression by using key formulas, defined for the perfect electromagnetic conductor and absorbing surfaces. The scattering integral is asymptotically evaluated for large values of the wave-number and the diffracted and geometric optics fields are obtained. The behaviors of the derived field expressions are analyzed numerically.

High power and immunity high Q PMC packaged dual notch high power suspended defected stripline filter

In this paper, a novel high power high selective and high-Q packaged dual band air suspended stripline notch filter is presented. The notch frequencies, at 2.4 and 3.5 GHz, were designed using defected suspended stripline (DSS). Moreover, the filter was packaged and shielded using perfect magnetic conductor (PMC). The DSS were designed using two frequency independent non-coupled cascaded U shape resonators. It has been proved that the filter attenuation has a sharp rejection characteristic (measured) at the two resonance frequencies (27 dB at 2.4 GHz) and (30 dB at 3.5 GHz) with Quality factor = (18). So, the sharp measured filter attenuation performance was further enhanced to become 38 dB at the two frequencies. The achieved results are discussed and confirmed using different circuit, 3D EM and experimental measurements. The designed filter can find many medium powers up to 20 kW applications.

Ka-Band Diplexer for 5G mmWave Applications in Inverted Microstrip Gap Waveguide Technology

A new cost-efficient, low-loss Ka-band diplexer designed in inverted microstrip gap waveguide technology is presented in this paper. Gap waveguide allows to propagate quasi-TEM modes in the air between two metal plates without the need for contact between them by using periodic metasurfaces. The diplexer is realized by using a bed of nails as AMC (Artificial Magnetic Conductor), first modeled with a PMC (Perfect Magnetic Conductor) surface for design simplification, and two fifth order end-coupled passband filters (BPFs) along with a power divider. The experimental verification confirms that the two channels centered at 24 GHz and 28 GHz with 1 GHz of bandwidth show measured insertion losses of 1.5 dB and 2 dB and 60 dB of isolation between them. A slight shift in frequency is observed in the measurements that can be easily explained by the variation in the permittivity of the substrate.

Reconfigurable epsilon-near-zero metasurfaces via photonic doping

The next generation of flat optic devices aspires to a dynamic control of the wavefront characteristics. Here, we theoretically investigated the reconfigurable capabilities of an epsilon-near-zero (ENZ) metasurface augmented with resonant dielectric rods. We showed that the transmission spectrum of the metasurface is characterized by a Fano-like resonance, where the metasurface behavior changed from perfect magnetic conductor to epsilon-and-mu-near-zero material responses. The abrupt variation between these two extreme material responses suggests potential applications in dynamic metasurfaces. We highlighted the causality aspects of ENZ metasurfaces with a transient analysis and numerically investigated different reconfigurable mechanisms. Thus, this work introduces a new strategy for dynamic wavefront engineering.

A Triangular-shaped Quarter-mode Substrate Integrated Waveguide based Antenna for WBAN Applications

<p class="Abstract">In this study, a compact quarter-mode substrate integrated waveguide (QMSIW) based dual-band antenna is proposed for wireless body area network applications. A QMSIW resonator is realised by splitting the full-mode substrate integrated waveguide cavity along the perfect magnetic conductor walls. The proposed antenna preserves the fundamental mode TE110 and the third order mode TE220 of the square SIW cavity. The proposed antenna is linearly polarised in the lower band at 2.45 GHz and circularly polarised in the higher frequency band at 5.8 GHz. The on-body performance of the antenna is validated on a piece of pork muscle tissue and it has been found to be stable with respect to surroundings. The proposed antenna covers the ISM bands 44 MHz (2.445 GHz - 2.489 GHz) and 225 MHz (5.730 GHz - 5.955 GHz) at 2.45 GHz and 5.8 GHz, respectively. The measured gain of the antenna on pork tissue is 1.87 dBi and 5.5 dBi at two bands. In addition, the specific absorption rate is obtained of 0.65 mW/g and 1.51 mW/g at two bands (wext = 2 mm), averaged over 1 g of muscle with 100mW input power. Moreover, the simulated and experimental results demonstrate a good agreement.</p>