Journal of Microwaves, Optoelectronics and Electromagnetic Applications 

About: Journal of Microwaves, Optoelectronics and Electromagnetic Applications is an academic journal published by Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo. The journal publishes majorly in the area(s): Antenna (radio) & Microstrip antenna. It has an ISSN identifier of 2179-1074. It is also open access. Over the lifetime, 539 publications have been published receiving 2715 citations.

Study of different shape Electromagnetic Band Gap (EBG) structures for single and dual band applications

Abstract: In this paper, single and dual band EBG structures for wider bandwidth are proposed. In each of the discussed EBGs, a metallic patch of regular geometry is chosen for the unit element. The patch is further modified by cutting slots to get extra inductance and capacitance which results into lower cut-off frequency and larger bandwidth. The proposed EBG structures are compared with the standard mushroom type EBG with respect to surface wave attenuation. The -20 dB cut-off frequencies and bandwidths of the various EBGs are compared. The effect of unit element size, gap between unit elements and via diameter on the transmission response is presented. Among the discussed EBGs, the swastika type structure is compact, single band and has wider bandwidth. The square patch with a single disconnected loop type slot EBG and the Fractal EBG are dual band. While square patch is more compact, the fractal EBG has wider bandwidth. All the EBGs can be useful in the design of antenna and other microwave circuits.

Unified method for the prediction of rain attenuation in satellite and terrestrial links

Abstract: In this paper, a semi-empirical method for the prediction of rain attenuation in slant paths and terrestrial links is proposed. The method uses the same simplified model of equivalent rain cell that is the basis for the ITU-R rain attenuation prediction methods but, additionally, the concept of an effective rain rate is introduced. This allows the use of the full rainfall rate distribution for the prediction of the rain attenuation distribution and the unification of the slant path and terrestrial links prediction algorithms. The numerical coefficients in the method’s expressions were derived by multiple non-linear regressions using the experimental data currently available in the ITU-R data banks. Test results indicate that the proposed method provides significant improvement over the current ITU-R methods.

Etched fiber bragg gratings sensors for water-ethanol mixtures: a comparative study

Abstract: In this work is evaluated the performance of etched fiber Bragg gratings, assembled in different configurations to operate as a refractometric sensor, in the analysis of water-ethanol mixtures. Two fiber Bragg gratings operating close to 1300 nm and 1500 nm were wet-etched and employed in the sensor design. Four configurations for the refractometric sensor were studied, in dual-wavelength and single-wavelength operation modes, and at two sample temperatures. Calibration curves were determined for the range between 0.0 and 100.0 % v/v of water in ethanol, and the sensor performance for each configuration was analyzed by comparing its sensitivity, conformity, repeatability and combined uncertainty. The best results showed that the sensor can be used to measure the ethanol-water concentration with combined uncertainty of 2.8 % v/v for the range up to 80.0 % v/v of ethanol concentration and 7.0 % v/v of uncertainty for the range above 80.0 % v/v of ethanol concentration for the single-wavelength operation mode at two temperatures.

Investigation on Metamaterial Antenna for Terahertz Applications

Abstract: In this paper, the metamaterial based rectangular microstrip patch antenna is proposed and designed for THz applications. The proposed antenna is designed with the help of circular split ring resonator as unit cell which is considered as metamaterial. By incorporating metamaterial in the conventional microstrip patch antenna, the size is reduced and the performance of antenna is improved. The proposed antenna has the dimensions of 180 × 212 ×10 µm 3 which is designed on Quartz substrate which is fed by microstrip line feed technique. Additionally, the performance of the metamaterial antenna is analyzed by varying unit cell gap size and thickness. The antenna resonates at 1.02 THz which gives the return loss of -65 dB. Thus, the proposed antenna can be utilized in THz region.

On the design of nano-arm fractal antenna for UWB wireless applications

Abstract: This paper presents the design of a nano-arm fractal antenna suitable for ultra wide band applications. The CPW-feed and fractal concept have been used to achieve the ultra wide bandwidth. The shape of the fractal geometry, the number of iterations and the number of nano-arms are the deciding factors for achieving wider impedance bandwidth. The experimental result of the fractal antenna exhibits ultra wideband characteristics in the frequency range of 2.55 GHz to 11.84 GHz corresponding to an impedance bandwidth of 131.77%. The measured radiation patterns of the proposed antenna are nearly omni-directional in the H - plane and bidirectional in the E-plane. The antenna can be useful for modern wireless communication, medical imaging and ground penetrating radar.