Now showing items 81-92 of 92
| Abstract: | A novel dual frequency dual-polarized square microstrip patch antenna embedded with a slot is presented. The proposed antenna offers tunability of the frequency ratio between the two frequencies by adjusting the slot dimensions. This configuration also provides a size reduction up to -51 and 35% for the two modes as compared to a square micro strip patch antenna |
| URI: | http://dyuthi.cusat.ac.in/purl/1371 |
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| Single-feed dua ... are microstrip antenna.PDF | (1.456Mb) |
| Abstract: | A novel dual frequency design of a square microstrip antenna coaxially fed along the diagonal with a chip capacitor mounted at the bottom of the stub is introduced. This design provides enhanced area reduction and good cross-polarization levels. The antenna design can be used as a compact antenna system where limited size is a major requirement. The details of the antenna design and experimental results are presented |
| URI: | http://dyuthi.cusat.ac.in/purl/1382 |
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| Slot coupled sq ... al-frequency operation.PDF | (1.351Mb) |
| Abstract: | Dual frequency operation is achieved from a compact microstrip antenna by loading a pair of narrow slots close to its radiating edges. The two frequencies have parallel polarization planes and similar radiation characteristics. The ratio between the two operating frequencies can be tuned in the range (1.14-1. 24), which is much smaller than that of similar designs. The above excellent radiation characteristics are achieved along with an area reduction of - 75% compared to the standard rectangular patch |
| URI: | http://dyuthi.cusat.ac.in/purl/1378 |
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| Slot-loaded com ... al-frequency operation.PDF | (1.081Mb) |
| Abstract: | The use of a split-ring resonator (SRR)-loaded waveguide for the design of a band-rejection filter with adjustable bandwidth is reported. The width of the stopband can be adjusted by suitably positioning the SRR array in the waveguide. The rejection band can be made very narrow by placing the array at the electric-field minimum. The stopband attenuation depends on the number of unit cells in the array. |
| URI: | http://dyuthi.cusat.ac.in/purl/2737 |
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| Dyuthi-P00371.pdf | (206.8Kb) |
| 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 |
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| Dyuthi-P00373.pdf | (1.186Mb) |
| Abstract: | An ultra-wideband (UWB) printed slot antenna, suitable for integration with the printed circuit board (PCB) of a wireless universal serial-bus (WUSB) dongle is presented. The design comprises a near-rectangular slot fed by a coplanar waveguide printed on a PCB of width 20 mm. The proposed design has a large bandwidth covering the 3.1-10.6 GHz UWB band, unaffected by the ground length, and omnidirectional radiation patterns. A linear phase response throughout the band further confirms its suitability for high-speed wireless connectivity. |
| URI: | http://dyuthi.cusat.ac.in/purl/2723 |
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| Dyuthi-P00360.pdf | (240.7Kb) |
| Abstract: | A compact ultra-wideband (UWB) printed slot antenna is described, suitable for integration with the printed circuit board (PCB) of a wireless, universal, serial-bus dongle. The design comprises of a near-rectangular slot fed by a coplanar waveguide (CPW) printed on a PCB of size 20 × 30 mm2. It has a large bandwidth covering the 3.1–10.6 GHz UWB band, with omnidirectional radiation patterns. Further, a notched band centered at 5.45 GHz wireless local area network bands is obtained within the wide bandwidth by inserting a narrow slot inside the tuning stub. Details of the antenna design are described, and the experimental results of the constructed prototype are presented. The time domain studies on the antenna shows a linear phase response throughout the band except at the notched frequency. The transient analysis of the antenna indicates very little pulse distortion confirming its suitability for high speed wireless connectivity. |
| URI: | http://dyuthi.cusat.ac.in/purl/2719 |
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| Dyuthi-P00354.pdf | (401.1Kb) |
| Abstract: | In this paper, we introduce a novel feeding technique for bandwidth enhancement of a rectangular microstrip antenna This antenna offers an impedance bandwidth of 22% without degrading the effciencv. The effect of the feed parameters upon patch characteristics such as resonant frequency, impedance bandwidth, and radiation pattern are studied in detail. The experimental results are verified using the FDTD results |
| URI: | http://dyuthi.cusat.ac.in/purl/1415 |
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| Wideband micros ... using hook-shaped feed.PDF | (1.285Mb) |
| Abstract: | The design and development of an L-band printed dipole antenna. optimized for wide-band applications near first resonance, is reported. This design has achieved more than 48% impedance bandwidth (VSWR 2:1), without degrading its overall radiation efficiency |
| URI: | http://dyuthi.cusat.ac.in/purl/1363 |
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| WIDE-BAND PRINTED DIPOLE ANTENNA.PDF | (1.256Mb) |
| Abstract: | A simple electromagnetically coupled wideband printed microstrip antenna having a 2:1 VSWR bandwidth of 38% covering the 5.2/5.8-GHz WLAN, HIPERLAN2, and HiSWANa communication bands is presented. The large bandwidth is obtained by adding a rectangular metal strip on a slotted square microstrip antenna. The antenna occupies an overall dimension of 42 times 55 times 3.2 mm3 when printed on a substrate of dielectric constant 4. It exhibits good radiation characteristics and moderate gain in the entire operating band. Details of the design along with experimental and simulation results are presented and discussed. |
| URI: | http://dyuthi.cusat.ac.in/purl/2717 |
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| Dyuthi-P00355.pdf | (587.6Kb) |
| Abstract: | An electromagnetically coupled T-shaped microstrip feed used to enhance the impedance bandwidth of a rectangular microstrip antenna is reported. The proposed antenna offers a 2:1 VSWR bandwidth of -36% with an increase in gain of 0.8 dB |
| URI: | http://dyuthi.cusat.ac.in/purl/1400 |
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| A wideband rect ... ymmetric t-shaped feed.PDF | (804.7Kb) |
| 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 |
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| Wideband trapez ... of specular reflection.PDF | (808.9Kb) |
Now showing items 81-92 of 92
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