Jayashree P. Shinde

On the design of CPW-fed square octal shaped fractal UWB antenna

This paper presents the design of an ultra wide band (UWB) antenna with CPW-fed. The antenna has been designed on FR4 substrate εr = 4.3 and thickness 1.53 mm. The antenna has been fabricated and tested using VNA. The experimental results of this antenna offer ultra wide bandwidth from 2.86 GHz to 14.38 GHz. This corresponds to the impedance bandwidth 11.42 GHz and 132.48 %. The experimental results also exhibits the first band from 0.62 GHz to 1.657 GHz corresponds to 1.037 GHz bandwidth. The radiation pattern of this antenna is nearly omni directional. This type of antenna can be used for ultra wide band system, positioning system, microwave imaging and Radar application.

Circular polarization in transparent circular patch with defected structure

This paper presents an optically transparent circular shaped microstrip patch antenna. The transparent circular microstrip antenna comprises a thin sheet of soda lime glass substrate with conductive ITO film coating for radiating patch and ground plane and is feed through a CPW feeding technique. The circular shaped patch is modified by inserting inset slit, rectangular slit in patch and nearly rectangular slot in the ground plane for more optical transparent characteristics and shifting resonating frequency toward lower side as well. The targeting frequency of this antenna is 2.4 GHz. The impedance bandwidth of proposed antenna is 3.6 GHz(2GHz-5.6GHz), while the radiation efficiency is 89%. The peak gain over the operating bandwidth is 3.6 dB. The optical transparency is enhanced from 90% to 94.44% due to the use of defected structures both in patch and ground plane. The antenna is circular polarization in nature with axial ratio bandwidth of 1.91 GHz and is a candidate of S-band application.

CPW feed electromagnetic Y shaped feeding technique for circular polarization & bandwidth enhancement

This paper presents planar modified circular slot antenna with asymmetric Y-shaped feeding technique. The CPW asymmetric Y-shaped feeding structure is electromagnetically coupled to the modified circular shaped radiating patch. The proposed antenna is made circularly polarized by innovative Y-shaped asymmetric arm feeding structure. The antenna covers the impedance bandwidth of 2.04GHz–4.38GHz with center frequency 2.49 GHz. The impedance bandwidth of the proposed antenna is improved and enhanced compared with the reference antenna. The circular polarization purity at resonant frequency is achieved by the proposed feeding technique. The fractional bandwidth achieved is of 72.89%, while the axial ratio bandwidth is 73.33MHz. The radiation patterns are bipolar in nature in E & H plane. The peak gain 5.13dB and the VSWR bandwidth 2.4GHz (2.02GHz–4.4GHz)of the proposed antenna finds the wireless application, such as 802.11b/2.5GHz and 802.16e/3.5GHz.

Circularly polarized transparent equilateral triangular shaped antenna with defected ground

This paper presents an optically transparent equilateral triangular shaped microstrip patch antenna made of transparent ITO (Indium Tin Oxide) film. The transparent triangular microstrip antenna comprises a thin sheet of soda lime glass substrate with conductive ITO film coating radiating patch and ground plane and is feed through a CPW feeding technique. The inverted L-shape slot in the ground is used to make the patch more optically transparent and to shift the resonating frequency toward lower side. The targeting frequency of this antenna is 2.5 GHz. The reflection coefficient of resonating frequency is observed −56 dB. The impedance bandwidth of proposed antenna is 2.19 GHz (2.12GHz – 4.31GHz), while the radiation efficiency is of 89%. The peak gain over the operating bandwidth is 3.10 dB. The antenna is circular polarization in nature with axial ratio bandwidth of 1.97 GHz and is a candidate of S-band application.

Effect of superstrates on the resonant frequency of a circularly polarized nearly circular annular ring patch

This paper presents the effect on resonant frequency of multilayer circular annular ring microstrip antenna. Three nearly circular annular ring microstrip antennas (ARMSA) have been fabricated on FR4 substrate of dielectric constant 4.3 and thickness 1.53mm of various dimensions. Experimental resonant frequency of simple circular ARMSA, covered circular ARMSA, spaced dielectric circular ARMSA and circular ARMSA with two superstrates have been measured and compared with the calculated resonant frequency from full wave analysis. The average % deviation of all these ARMSA are respectively found as -0.278%, 1.03%, -0.535% and 0.5%. The measured and calculated resonant frequencies are in good agreement. The Simple nearly circular ARMSA, fed diagonally at the center of the radiating patch is studied for circular polarization (CP) with 3dB Axial Ratio bandwidth. The three types of ARMSA has been designed and fabricated and found to have a CP-3 dB axial ratio bandwidth of 5.2%, 4.16% and 2.06% at their center fundamental resonant frequency. This type of study is useful for wideband, high gain antenna and to calculate the radome and environmental effect on resonant frequency.