The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Subrata Sanyal - One of the best experts on this subject based on the ideXlab platform.
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Compact harmonic suppression branch-Line coupler using signal-interference technique
2016 Asia-Pacific Microwave Conference (APMC), 2016Co-Authors: Vamsi Krishna Velidi, A. V. G. Subramanyam, V. Senthil Kumar, Yateendra Mehta, Subrata SanyalAbstract:A novel application of signal-interference technique to branch-Line coupler design is proposed for miniaturization and wideband harmonic passband suppression. The coupler's second, third and fourth harmonic passband responses are attenuated due to a pole at each of these harmonics. Design equations and graphs are provided using Lossless Transmission Line model. A prototype coupler, having a compact (λ g /6)2 area, that is 44.4% of the (λ g /4)2 conventional coupler area, is fabricated in microstrip form for validation purposes. The input matching, isolation, amplitude and phase balance bandwidths of the proposed coupler are comparable to those of the conventional coupler.
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Dual-Transmission-Line Microstrip Equiripple Lowpass Filter with Sharp Roll-Off
ETRI Journal, 2011Co-Authors: Vamsi Krishna Velidi, Subrata SanyalAbstract:A novel application of a dual-Transmission Line is proposed to design a lowpass filter (LPF). The proposed structure uses only Transmission Line elements to produce an equiripple LPF response with sharp roll-off. Design equations are derived using a Lossless Transmission Line model. Controlling the electrical lengths, three Transmission-zeros are realized in the stopband to obtain a sharp roll-off rate and wide stopband bandwidth. A single unit microstrip LPF with a 3-dB cut-off frequency at 1.0 GHz having a roll-off of 135 dB/GHz along with a stopband bandwidth of 69.5% is designed for validation.
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A compact-size microstrip rat-race coupler with high performance
IEEE Technology Students' Symposium, 2011Co-Authors: Vamsi Krishna Velidi, Sarika Shrivastava, Subrata SanyalAbstract:A compact slow-wave microstrip rat-race coupler is presented. The present asymmetrical T-structure slow-wave loading achieves size reduction more than that obtained using traditional symmetrical T-structure along with wide range harmonic suppression performance. Lossless Transmission Line model is used to derive the design equations. A compact RRC occupying only 34% of the conventional RRC at 1.0 GHz with no harmonic passband up to 6.0 GHz is demonstrated for validation using two fullwave electromagnetic simulators and the results are in good agreement.
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Sharp-rejection microstrip bandpass filters with multiple Transmission zeros
AEU - International Journal of Electronics and Communications, 2010Co-Authors: Vamsi Krishna Velidi, Subrata SanyalAbstract:A simple design of a sharp-rejection microstrip bandpass (BPF) filter is presented. By creating multiple Transmission zeros in the lower and upper stopbands, sharp rejection characteristics are obtained. The basic filter unit consists of a single parallel coupled-Line section and an open-ended stub. A Lossless Transmission Line model approach is used to derive the design equations for frequency responses and Transmission zero positions. The bandwidths are controllable by the zero locations that in turn are controlled by varying the impedances of the configuration. To validate theoretical predictions, two prototype BPFs operating at lower band 2.4 GHz of WLAN are fabricated in microstrip form.
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Sharp-Rejection Ultra-Wide Bandstop Filters
IEEE Microwave and Wireless Components Letters, 2009Co-Authors: Vamsi Krishna Velidi, Ajay Babu Guntupalli, Subrata SanyalAbstract:In this letter, a modified optimum bandstop filter (BSF) design is presented. Broad stopband and sharp rejection characteristics are achieved by realizing three Transmission zeros near the passband edges. Stopband rejection depth and bandwidth can be controlled by the impedances of the configuration. A Lossless Transmission Line model analysis is used to derive design equations. Further, a compact geometry is chosen by replacing the low impedance section with its equivalent dual-high impedance Lines, which facilitates convenient folding. To validate the theoretical prediction, a single unit sharp-rejecting prototype BSF having a 20 dB rejection bandwidth of 126% at 1.5 GHz has been fabricated.
Mrinal Kanti Mandal - One of the best experts on this subject based on the ideXlab platform.
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miniaturization of a 90 hybrid coupler with improved bandwidth performance
IEEE Microwave and Wireless Components Letters, 2016Co-Authors: Sudini Reshma, Mrinal Kanti MandalAbstract:This letter presents a compact hybrid coupler having wider bandwidth compared to a conventional 90° branch Line coupler. Coupling between two closely spaced branches is utilized for the improvement. Closed form expressions are derived using a Lossless Transmission Line theory. Further, graphs are presented to determine size of the coupler with the required bandwidth specifications. In the bandwidth calculation, input matching, isolation, phase and amplitude imbalances, all conditions are considered simultaneously. A coupler is fabricated on a 1.58 mm thick FR4 substrate. It occupies 33% area of a conventional branch Line coupler. The measured fractional bandwidths for the input matching, isolation, phase and amplitude imbalance conditions are 19.6%, 12.4%, 41.9% and 35.2%, respectively, which is higher than a conventional one.
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Miniaturization of a 90° Hybrid Coupler with Improved Bandwidth Performance
IEEE Microwave and Wireless Components Letters, 2016Co-Authors: Sudini Reshma, Mrinal Kanti MandalAbstract:This letter presents a compact hybrid coupler having wider bandwidth compared to a conventional 90° branch Line coupler. Coupling between two closely spaced branches is utilized for the improvement. Closed form expressions are derived using a Lossless Transmission Line theory. Further, graphs are presented to determine size of the coupler with the required bandwidth specifications. In the bandwidth calculation, input matching, isolation, phase and amplitude imbalances, all conditions are considered simultaneously. A coupler is fabricated on a 1.58 mm thick FR4 substrate. It occupies 33% area of a conventional branch Line coupler. The measured fractional bandwidths for the input matching, isolation, phase and amplitude imbalance conditions are 19.6%, 12.4%, 41.9% and 35.2%, respectively, which is higher than a conventional one.
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Compact Wideband Bandstop Filter With Five Transmission Zeros
IEEE Microwave and Wireless Components Letters, 2012Co-Authors: Mrinal Kanti Mandal, K. Divyabramham, Vamsi Krishna VelidiAbstract:A compact parallel-coupled Transmission Line section, connected at their both ends, is presented to obtain multiple Transmission zeros. As much as five Transmission zeros can be obtained. The zeros can be arranged to design a sharp rejection wideband bandstop filter (BSF). A Lossless Transmission Line model is used to analyze the structure and hence to obtain closed form expressions for the -parameters and design graphs to facilitate the filter synthesis procedure. Theoretical predictions are validated by fabricating a BSF in microstrip Line technology. The single filter unit provides 29 dB stopband over a fractional bandwidth of 60% at the mid-band frequency of 1.47 GHz.
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design of dual band bandpass filters using stub loaded open loop resonators
IEEE Transactions on Microwave Theory and Techniques, 2008Co-Authors: Priyanka Mondal, Mrinal Kanti MandalAbstract:In this paper, open-loop resonators loaded by shunt open stubs are proposed to design compact dual-band bandpass filters with improved out-of-band rejection characteristics. The second passband of the dual-band filter is obtained by tuning higher resonant modes of the open-loop resonator by the stub length and position. A tapped-Line input/output feed structure is used for external coupling. Required external coupling is obtained by adjusting the tapping position and dimension of the stub-loaded resonator. A Lossless Transmission Line model is used to determine the resonance properties of the resonator and the external quality factor. Theoretical predictions are verified by the experimental results of three dual-band filters.
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Compact, Wideband Bandstop Filters With Sharp Rejection Characteristic
IEEE Microwave and Wireless Components Letters, 2008Co-Authors: Mrinal Kanti Mandal, K. Divyabramham, Subrata SanyalAbstract:A compact unit of parallel coupled Transmission Line is presented for design of a compact, sharp-rejection, wideband bandstop filter (BSF). The rejection depth and bandwidth can be easily controlled by the coupled-Line parameters. A Lossless Transmission Line model is used for filter analysis. Design equations and graphs are presented in order to facilitate the design procedure. Theoretical prediction is verified in microstrip Line by fabricating a prototype single section coupled-Line BSF.
Kyu-pyung Hwang - One of the best experts on this subject based on the ideXlab platform.
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A total-variation-diminishing finite-difference scheme for the transient response of a Lossless Transmission Line
IEEE Transactions on Microwave Theory and Techniques, 1998Co-Authors: Kyu-pyung HwangAbstract:Total-variation-diminishing (TVD) finite-difference schemes have been used in computational fluid dynamics for accurate solutions of fluid problems involving shock phenomena. This paper investigates the possibility of their application in transient electromagnetic-wave problems. A Lossless Transmission Line with a resistive load is considered to illustrate the application. A TVD Lax-Wendroff finite-difference scheme is presented for the numerical solution of Transmission-Line equations in time domain. Numerical results show that the TVD scheme can approximate the discontinuous waveforms with remarkable accuracy.
Liu Nan - One of the best experts on this subject based on the ideXlab platform.
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a method to judge demand of uhv Transmission Lines on steady state over voltage device based on Lossless Transmission Line theory
Power system technology, 2011Co-Authors: Liu NanAbstract:Based on Lossless Transmission Line theory,a formula to calculate the voltage distribution along ultra high voltage(UHV) Transmission Line,which is connected to power grid under no-load condition,is derived.During the derivation of the formula,the parameters of UHV Transmission Line and configuration of high voltage reactor in disconnected no-load Transmission Line are comprehensively considered,and the extreme length of UHV Transmission Line under different grid voltage connected to no-load UHV Transmission Line.Under the same voltage connected to no-load UHV Transmission Line,if actual length of UHV Transmission Line exceeds the extreme length,it is necessary to configure steady-state overvoltage device to avoid such a condition that the voltage along the connected no-load UHV Transmission Line exceeds 1000kV.The proposed method remedy the defect of exising judging methods that depend on power system simulation software and a lot of simulations have to performed.Comparison of the judged result by the proposed method with the result from PSD-BPA simulation software shows that the proposed method can give accurate and reliable result.
Vamsi Krishna Velidi - One of the best experts on this subject based on the ideXlab platform.
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Compact harmonic suppression branch-Line coupler using signal-interference technique
2016 Asia-Pacific Microwave Conference (APMC), 2016Co-Authors: Vamsi Krishna Velidi, A. V. G. Subramanyam, V. Senthil Kumar, Yateendra Mehta, Subrata SanyalAbstract:A novel application of signal-interference technique to branch-Line coupler design is proposed for miniaturization and wideband harmonic passband suppression. The coupler's second, third and fourth harmonic passband responses are attenuated due to a pole at each of these harmonics. Design equations and graphs are provided using Lossless Transmission Line model. A prototype coupler, having a compact (λ g /6)2 area, that is 44.4% of the (λ g /4)2 conventional coupler area, is fabricated in microstrip form for validation purposes. The input matching, isolation, amplitude and phase balance bandwidths of the proposed coupler are comparable to those of the conventional coupler.
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Compact Wideband Bandstop Filter With Five Transmission Zeros
IEEE Microwave and Wireless Components Letters, 2012Co-Authors: Mrinal Kanti Mandal, K. Divyabramham, Vamsi Krishna VelidiAbstract:A compact parallel-coupled Transmission Line section, connected at their both ends, is presented to obtain multiple Transmission zeros. As much as five Transmission zeros can be obtained. The zeros can be arranged to design a sharp rejection wideband bandstop filter (BSF). A Lossless Transmission Line model is used to analyze the structure and hence to obtain closed form expressions for the -parameters and design graphs to facilitate the filter synthesis procedure. Theoretical predictions are validated by fabricating a BSF in microstrip Line technology. The single filter unit provides 29 dB stopband over a fractional bandwidth of 60% at the mid-band frequency of 1.47 GHz.
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Dual-Transmission-Line Microstrip Equiripple Lowpass Filter with Sharp Roll-Off
ETRI Journal, 2011Co-Authors: Vamsi Krishna Velidi, Subrata SanyalAbstract:A novel application of a dual-Transmission Line is proposed to design a lowpass filter (LPF). The proposed structure uses only Transmission Line elements to produce an equiripple LPF response with sharp roll-off. Design equations are derived using a Lossless Transmission Line model. Controlling the electrical lengths, three Transmission-zeros are realized in the stopband to obtain a sharp roll-off rate and wide stopband bandwidth. A single unit microstrip LPF with a 3-dB cut-off frequency at 1.0 GHz having a roll-off of 135 dB/GHz along with a stopband bandwidth of 69.5% is designed for validation.
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A compact-size microstrip rat-race coupler with high performance
IEEE Technology Students' Symposium, 2011Co-Authors: Vamsi Krishna Velidi, Sarika Shrivastava, Subrata SanyalAbstract:A compact slow-wave microstrip rat-race coupler is presented. The present asymmetrical T-structure slow-wave loading achieves size reduction more than that obtained using traditional symmetrical T-structure along with wide range harmonic suppression performance. Lossless Transmission Line model is used to derive the design equations. A compact RRC occupying only 34% of the conventional RRC at 1.0 GHz with no harmonic passband up to 6.0 GHz is demonstrated for validation using two fullwave electromagnetic simulators and the results are in good agreement.
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Sharp-rejection microstrip bandpass filters with multiple Transmission zeros
AEU - International Journal of Electronics and Communications, 2010Co-Authors: Vamsi Krishna Velidi, Subrata SanyalAbstract:A simple design of a sharp-rejection microstrip bandpass (BPF) filter is presented. By creating multiple Transmission zeros in the lower and upper stopbands, sharp rejection characteristics are obtained. The basic filter unit consists of a single parallel coupled-Line section and an open-ended stub. A Lossless Transmission Line model approach is used to derive the design equations for frequency responses and Transmission zero positions. The bandwidths are controllable by the zero locations that in turn are controlled by varying the impedances of the configuration. To validate theoretical predictions, two prototype BPFs operating at lower band 2.4 GHz of WLAN are fabricated in microstrip form.
