Now showing items 21-27 of 27
| Abstract: | This paper presents the design of a new type of corner reflector (CR) antenna and the experimental investigation of its radiation characteristics. The design involves the addition of planar parallel periodic strips to the two sides of a CR antenna. The position, angular orientation, and number of strips have a notable effect on the H-plane radiation characteristics of the antenna. Certain configurations of the new antenna are capable of producing very sharp axial beams with gain on the order of 5 dB over the square corner reflector antenna. A configuration that can provide symmetric twin beams with enhanced gain and reduced half-power beam width (HPBW) is also presented. |
| URI: | http://dyuthi.cusat.ac.in/purl/2980 |
| Files | Size |
|---|---|
| Dyuthi-P00415.pdf | (146.7Kb) |
| Abstract: | HIV/AIDS is one of the most destructive epidemics in ever recorded history claims an estimated 2.4 –3.3 million lives every year. Even though there is no treatment for this pandemic Elisa and Western Blot tests are the only tests currently available for detecting HIV/AIDS. This article proposes a new method of detecting HIV/AIDS based on the measurement of the dielectric properties of blood at the microwave frequencies. The measurements were made at the S-band of microwave frequency using rectangular cavity perturbation technique with the samples of blood from healthy donors as well as from HIV/AIDS patients. An appreciable change is observed in the dielectric properties of patient samples than with the normal healthy samples and these measurements were in good agreement with clinical results. This measurement is an alternative in vitro method of diagnosing HIV/AIDS using microwaves. |
| URI: | http://dyuthi.cusat.ac.in/xmlui/purl/2052 |
| Files | Size |
|---|---|
| A novel method of detecting...pdf | (156.8Kb) |
| Abstract: | In this paper we have investigated the effect of cavity diameter and wall height on resonance and radiation characteristics of a circular microstrip patch antenna. Experiments were conducted using a fabricated prototype placed inside a cylindrical cavity. The results were compared and verified with simulated data obtained using an electromagnetic simulator. About 9.6 to 10.5 dBi peak gain was obtained from measured and simulated data |
| URI: | http://dyuthi.cusat.ac.in/purl/1088 |
| Files | Size |
|---|---|
| APSYM-08 (G).zip | (27.35Mb) |
| Abstract: | A simple and efficient method for determining the complex permittivity of dielectric materials from both reflected and transmitted signals is presented. It is also novel because the technique is implemented using two pyramidal horns without any focusing mechanisms. The dielectric constant of a noninteractive and distributive (NID) mixture of dielectrics is also determined |
| URI: | http://dyuthi.cusat.ac.in/purl/1374 |
| Files | Size |
|---|---|
| Dyuthi-P00418.pdf | (452.6Kb) |
| Abstract: | The radiation characteristics of a new type of hollow dielectric H-plane sectoral horn antenna are presented. Metallic strips of optimum length are loaded on the H-walls of the sectoral horns. The effects of strip loading for producing square patterns in the H plane are discussed. |
| URI: | http://dyuthi.cusat.ac.in/purl/2977 |
| Files | Size |
|---|---|
| Dyuthi-P00412.pdf | (115.5Kb) |
| Abstract: | Despite its recognized value in detecting and characterizing breast disease, X-ray mammography has important limitations that motivate the quest for alternatives to augment the diagnostic tools that are currently available to the radiologist. The rationale for pursuing electromagnetic methods are based on the significant dielectric contrast between normal and cancerous breast tissues, when exposed to microwaves. The present study analyzes two-dimensional microwave tomographic imaging on normal and malignant breast tissue samples extracted by mastectomy, to assess the suitability of the technique for early detection ofbreast cancer. The tissue samples are immersed in matching coupling medium and are illuminated by 3 GHz signal. 2-D tomographic images ofthe breast tissue samples are reconstructed from the collected scattered data using distorted Born iterative method. Variations of dielectric permittivity in breast samples are distinguishable from the obtained permittivity profiles, which is a clear indication of the presence of malignancy. Hence microwave tomographic imaging is proposed as an alternate imaging modality for early detection ofbreast cancer. |
| URI: | http://dyuthi.cusat.ac.in/purl/2739 |
| Files | Size |
|---|---|
| Dyuthi-P00373.pdf | (1.186Mb) |
| Abstract: | A trapezoidal strip grating surface that eliminates specular reflections almost over the entire X -band frequency range for TM polarization is reported This new grating structure overcomes the bandwidth limitation of conventional rectangular strip grating surfaces |
| URI: | http://dyuthi.cusat.ac.in/purl/1348 |
| Files | Size |
|---|---|
| Wideband trapez ... of specular reflection.PDF | (808.9Kb) |
Now showing items 21-27 of 27
Dyuthi Digital Repository Copyright © 2007-2011 Cochin University of Science and Technology. Items in Dyuthi are protected by copyright, with all rights reserved, unless otherwise indicated.