Design an ultra-wideband modified wilkinson power divider fed-by balanced antipodal vivaldi antenna array for imaging applications

In this paper, design of compact and modified geometrical structure of 1-to-4 way ultra-wideband Wilkinson power divider used as a feeding network for 4-element of balanced antipodal Vivaldi antenna (BAVA) array has introduced. The proposed Wilkinson power divider has been designed and printed on low-cost Epoxy laminate substrate FR4 along with the thickness of 1.6mm and relative permittivity of ɛr =4.3 respectively. The transformation of power divider network which are based on bent corners as a replacement of sharp corners or edges used for the decrement in unintended radiation and employing a single radial stub on each branch to encounter the antenna-specifications. Further some adjustments in the dimension of stubs matching in order to increase the reflection of the power divider network. The design presents the model of a power divider and maintains an equal power splitting at different ports with practical insertion loss and conventional return loss below -10dB. The reasonable impedance matching has achieved at every single port with acceptable isolation performance values over the (3-to-10 GHz) frequency range. The divider as well as antenna elements design and its optimization are practicable via computer simulation technology (CST) simulation software. The experimental results are revealed to encounter the array-specifications under ultra-wideband frequency range

Carbon nanotube bumps for the flip chip packaging system

Carbon nanotube [CNT] interconnection bump joining methodology has been successfully demonstrated using flip chip test structures with bump pitches smaller than 150 μm. In this study, plasma-enhanced chemical vapor deposition approach is used to grow the CNT bumps onto the Au metallization lines. The CNT bumps on the die substrate are then 'inserted' into the CNT bumps on the carrier substrate to form the electrical connections (interconnection bumps) between each other. The mechanical strength and the concept of reworkable capabilities of the CNT interconnection bumps are investigated. Preliminary electrical characteristics show a linear relationship between current and voltage, suggesting that ohmic contacts are attained

Comparative analysis of UWB balance Antipodal Vivaldi Antenna for array configuration

In this paper, an Ultra-wideband Balance Antipodal Vivaldi Antenna in planar and h-plane array configuration is presented. The comparison of four elements of BAVA array in both planes has been observed. Each element of an antenna printed on the glass-reinforced epoxy laminate material (FR4) with a thickness of 1.5mm and relative permittivity of 4.3. The dimension of every single element is 60.75mm x 66mm approximately. The array elements of both planes almost cover the whole UWB frequency range with the reflection coefficient of -10dB. Based on the simulation results, the array elements in planar configuration showing good reflection and works well at 3.2GHz frequency while the configuration in h-plane the array elements works well at 7GHz of frequency. In planar configuration, the operating frequency of antenna elements is shifting as a result of the distance between inter elements which intensification in wavelength. The array elements in h-plane produce more gain up to 10.2 dB with good radiation patterns as compared to the planar plane. The antenna design and optimization development are verified using CST simulation software

Design and parametric evaluation of UWB antenna for array arrangement

This paper has introduced the concept of UWB antenna in array arrangements. The four elements of Balance Antipodal Vivaldi Antenna (BAVA) has been used for planar and H-plane array configuration in this research. Each single element of BAVA Antenna is printed on the glass-reinforced epoxy laminate material (FR4) along an overall thickness of 1.57mm and εr=4.3 respectively. The optimized measurement of each particular element is 60.75mm x 66mm approximatel. Further the parametric evaluation of four BAVA elements in different planes has been observed in this paper. The placement of array elements has almost coverd entire UWB frequency range and appropriate reflection coefficient which is better than -10dB has been established in both combinations. According to simulation results, the array elements in planar arrangement presenting a suitable reflection and works well at 3.2GHz frequency while the arrangement in H-plane the array elements works well at 7GHz of frequency. In planar arrangement, the operating frequency of antenna elements is shifting as results of the distance among inter elements which increase in wavelength. In H-plane arrangement an antenna elements generate additional gain up to 10.2 dB with good radiation patterns as compared to the planar plane. The CSTMWS simulation software has been used for antenna structural design and parametric verification

UWB antenna based time-domain approach for through the walls gap estimation

This paper has introduced a novel experimental system adopted a time domain approach for estimating through wall distance and recognizes buried objects behind the wall. The designed and fabricated balanced antipodal Vivaldi antenna (BAVA) has been used for the development of UWB system. The working mechanism of an intended detection system based on time domain reflectometry (TDR) and ground-penetrating radar (GPR). A miniature pulse in the UWB range is generated by the vector network analyzer (VNA) to irradiate a barrier made of two walls separated by airgap between them. The signal radiations reflect partially from the front wall while remaining goes through for getting reflected from the rear wall. The VNA is used for measuring the time interval passed between the instant when an incident signal irradiates the first wall and the instant when the incident signal gets reflected from the rear wall. The investigational process of a system is carried out by UWB antenna probe. The detected information is attained using the values of reflection coefficient (S 11 ) represented in time domain measurements. Experimental results have been proved the ability to detect wall gap as well as the width estimation between two walls with high accuracy. The maximum percentage error has been found to not exceeding 4.5% in the worst condition

3D Radio-frequency to millimeter wave heterogeneous system integration: emerging nanotechnologies for RF nanopackaging

International audienc

Carbon Nanotubes as Microbumps for 3D Integration

International audienc

Tunable micro-machined combine filter.

International audienc

Thermal transport in C 20 fullerene-chained carbon nanobuds

International audienceCarbon nanobuds, which are hybrid fullerene-nanotube structures, have previously shown glimpses of their potential in nanotechnology applications. By performing molecular dynamics simulations, a novel study of thermal conduction in a compact form of carbon nanobuds is presented. We demonstrate that nanobuds conduct thermal energy relatively well, within an order compared to nanotubes. Alike their close relatives--the carbon peapod, this essentially extends the dimensionality of thermal management applications. A ..