Kumud Ranjan Jha

A SIMPLE SYNTHESIS TECHNIQUE OF SINGLE- SQUARE-LOOP FREQUENCY SELECTIVE SURFACE

In this manuscript, a simple synthesis method of single square loop frequency selective surface (SSLFSS) is discussed, which may flnd the suitable application in the fast analysis and fabrication of the frequency-selective surface. The presented technique is used to design SSLFSS at 3GHz, 15GHz, 22GHz and 26GHz. At every frequency of interest, the analytical result is very close to the required result. Moreover, a way to control the re∞ection at any frequency is discussed, which may flnd an application in controlling the re∞ection level at any frequency. However, we have proposed two simple, cheaper and lightweight structures at 3GHz and 22GHz for the application in various satellite communications. The proposed process has been extended to the analysis of bandpass structure and desired results have been achieved, which indicates the utility of the method of synthesis of both the bandpass and bandstop structures.

Terahertz Planar Antennas for next generation communication

Terahertz Sources and Antennas.- Multilayered microstrip transmission-line.- Microstrip Antenna Design by using Electromagnetic Bandgap Material.- Patch Array Antenna on EBG Substrate.- Ring-resonator Integrated Hemi-elliptical Lens Antenna.- Design of Highly Directive Cavity type Terahertz Antenna.- Performance Analysis of an Open-Loop Resonator Loaded Terahertz Microstrip Antenna.- Comparison Method to Predict the Directivity of Terahertz Patch Antenna.- THz Frequency Selective Surface.- Development in the Terahertz Communication System.

Design of compact printed antenna for 5.2/5.8 GHz WLAN and 3.5/5.5 GHz WiMAX wireless USB Dongle application

In this manuscript, a small reduced ground plane printed antenna to be used in WLAN/WiMax is analyzed. The reduced ground plane antenna is designed on the FR-4 substrate whose length width and thickness are 30 mm, 15 mm and 0.8 mm, respectively. The length and width of the antenna are 10 mm and 15 mm respectively. The compact antenna offers a wide bandwidth and may be used in WiMAX and WLAN Dongle applications.

Microstrip patch antenna on photonic crystal substrate at terahertz frequency

In this paper, a dielectric slab with the periodic implantation of the air gap in the host passive substrate material has been analyzed. The effective permittivity of the photonic crystal with host material PTFE at 600GHz has been extracted with the help of robust method to retrieve the constitutive effective parameters of the metamaterials. Based on the extracted effective permittivity, a rectangular microstrip patch antenna at terahertz regime of the electromagnetic spectrum on the 2-D photonic crystal has been designed and simulated by using CST Microwave Studio, a commercially available simulator based on the finite integral technique.

Circular ring frequency selective surface: A novel synthesis technique

In this paper, a simple synthesis method of the circular ring frequency selective surface has been discussed. However, the proposed technique is used to design circular ring frequency selective surface at 3GHz, 15 GHz and 26 GHz and analytical results of each frequency of interest has been supported by simulation results, which has been performed by using CST Microwave Studio a commercially available simulator based on the finite integral technique. For validation of the results, Ansoft Circuit Simulator has also been used to obtain the reflection and transmission coefficient through the values of inductance and capacitance, which have been achieved in the analysis process. Moreover, the effect of dielectric substrate as well as the effect of conductor thickness on the performance of frequency selective surface has also been discussed.

Terahertz dipole antenna in Fabry-Perot cavity with two side-walls to enhance the directivity

In this paper, the directivity enhancement mechanism of a dipole antenna placed in the Fabry-Perot type cavity is presented. The directivity of the antenna has been increased upto 19 dBi at 610 GHz. To validate the analysis, the antenna has been simulated by using two different commercially available simulators CST Microwave Studio and Ansoft HFSS.

Improved Performance Analysis of Square Patch Microstrip Antenna at Terahertz Frequency

In this paper improved performance microstrip square patch antenna at terahertz frequency range has been analyzed. The antenna has been designed to radiate at any frequency point in the frequency band of 0.5 to 0.7THz with high gain and radiation efficiency. The effect of various parameters of substrate on radiating patch has been investigated. Gain and radiation efficiency of 21.87 dB and 94.45% have been achieved respectively.

Constructive interference in Yagi-Uda type printed terahertz antenna on photonic crystal substrate

In this paper, a Yagi-Uda type printed antenna on the photonic crystal substrate at terahertz frequency regime has been investigated. An equivalent circuit model of the antenna has been proposed and a methodology to investigate various electrical parameters is discussed. A particular set of tuneable parameters of the structure has been used to investigate the effect of constructive interference. The effect of this mechanism helps to increase the gain, radiation efficiency and reduction in side-lobes significantly. The analysis is also compared by using two simulators, CST Microwave Studio based on finite integral technique and Ansoft HFSS based on finite element method. The gain of proposed antenna is 16.71 dB and minor lobes are suppressed by 9.3 dB in comparison to the main beam in the end-fire direction. The radiation efficiency of the proposed structure is 91.93 %.

Analysis of Dielectric Permittivity and Losses of Two-layer Substrate Materials for Microstrip Antenna at THz Frequency

In this paper, an effective dielectric permittivity and losses of two-layer substrate for rectangular microstrip patch antenna at THz frequency has been analyzed and simulated in the terahertz frequency regime surveillance system. The proposed antenna has been optimized at 600GHz frequency by CST Microwave Studio a commercially available simulator based on finite integral technique. To validate the design the structure has also been re-simulated with finite element based Ansoft HFSS commercial simulator.

Angular Stable, Dual-Polarized and Multiband Modified Circular Ring Frequency Selective Surface

Abstract In this paper, a single-layer multiband slot-type frequency selective surface (FSS), which consists of a modified circular ring loaded with concentric conventional circular ring, is discussed. We have emphasized to design an angular as well as polarization stable multiband FSS structure with reflection characteristics in S-band (2–4 GHz)/Ku (12–18 GHz) and transmission characteristics in X-band (8–12 GHz)/Ka-band (24–28 GHz). A novel synthesis technique is used to obtain the geometrical parameters of the proposed multiband FSS structure, which reduces the number of iterations in the computation process. The proposed multiband FSS structure satisfies the design issues of the frequency response in chosen frequency band of the electromagnetic spectrum and provides significant frequency stability as well as 3-dB bandwidth for both the perpendicular and parallel polarized wave incidence up to 50°. The slot-type modified circular ring FSS structure has been experimentally tested at X-band to validate the synthesis approach.