Proximity effects of a layered periodic structure on miniaturization of patch antennas

A miniaturized microstrip antenna on a planar layered periodic structure is proposed, designed and fabricated. The proposed structure miniaturizes patch antennas in the microwave band. With varying the parameters of the proposed structure, the achieved miniaturization factor can be adjusted in the range 2.6–4.2. Numerical and experimental results are presented. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.     

Study of a Surface Plasmon Resonance Optical Fiber Sensor Based on Periodically Grating and Graphene

Silicon - In this paper an optical fiber sensor based on plasmonic resonance of graphene and periodically grating is designed and investigated. The proposed sensor consists of an optical fiber core...     

A new spatiotemporal filtering method for single-trial estimation of correlated ERP subcomponents

A novel spatiotemporal filtering method for single trial estimation of event-related potential (ERP) subcomponents is proposed here. Unlike some previous works in ERP estimation [1], , the proposed method is able to estimate temporally correlated ERP subcomponents such as P3a and P3b. A new cost function is, therefore, defined which can deflate one of the correlated subcomponents. The method is applied to both simulated and real data and has shown to perform very well even in low signal-to-noise ratio situations. In addition, the method is compared to spatial principal component analysis and its superiority has been confirmed by using simulated signals. The approach can be especially useful in mental fatigue analysis where the relative variability of P300 subcomponents is the key factor in detecting the level of fatigue.     

Miniaturized low‐profile antenna based on uniplanar quasi‐composite right/left‐handed metamaterial

In this article, a metamaterial‐based broadband low‐profile antenna is presented. The proposed antenna employed an array of uniplanar quasi‐composite right/left‐hand (CRLH) metamaterial cells. This structure contributes to exciting the operating modes in lower frequencies. The antenna has an overall electrical size of 0.75 × 0.60 × 0.07 λ₀³ (λ₀ is the center operating wavelength in free space) and provides a 25% measured bandwidth with the center frequency of 5.1 GHz and maximum gain of 6.6 dB. The proposed antenna is an appropriate candidate for WLAN, WiMAX, and other wireless communication applications.     

Genetic algorithm design for nonperiodic planar graphene leaky-wave antennas in THz

The aim of this paper is proposing a new fast designing method for planar graphene leaky-wave antennas without periodical changes. Thus, Floquet theory cannot be used for designing, an optimization in numerical EM solver is needed. Since leaky-wave antennas are electrically long, their simulation using commercial EM simulators needs a large number of meshes, also the optimization of the large number of parameters (slot lengths and their distances) needs huge amount of memory and computation time. To resolve this problem, the method of Moments, implemented in MATLAB, which has been accelerated by applying some techniques, has been used in the design procedure. The antenna comprises a slotted graphene micro ribbon with a specific pattern, which is placed on two dielectric substrates and a PEC reflector. Graphene is used in the proposed LWA, instead of the electric conductor, because of its wonderful properties. The suitable pattern of slots on the graphene microstrip, is obtained using optimization by MATLAB Genetic algorithm tool. The usefulness and performance of the proposed designing approach, is verified in one example. It has been shown that the presented antenna, compared with one of the new successful similar antennas, has a better gain, radiation efficiency, and a wider range of beam scanning.