The Experts below are selected from a list of 3084 Experts worldwide ranked by ideXlab platform
Hawal Rashid - One of the best experts on this subject based on the ideXlab platform.
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Wideband Planar Hybrid With Ultralow Amplitude Imbalance
IEEE Microwave and Wireless Components Letters, 2017Co-Authors: Hawal Rashid, Parisa Yadranjee Aghdam, Denis Meledin, Vincent Desmaris, Victor BelitskyAbstract:We present a new design approach for the 90° directional coupler with very low Amplitude Imbalance. The primary feature of this quadrature coupler is the introduction of a controllable ripple in the operational band for achieving a better overall Amplitude balance. This design concept is demonstrated through a 90° branch-line hybrid for the 4–7.9 GHz band (65% fractional bandwidth) using microstrip transmission lines. Our simulations indicate that the Amplitude Imbalance of the designed hybrid is better than 0.3 dB over the most of the 4–7.9 GHz band with a phase Imbalance better than ±8.5°. Experimental verification of the hybrid shows excellent agreement with simulations.
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Design of Wideband Waveguide Hybrid With Ultra-Low Amplitude Imbalance
IEEE Transactions on Terahertz Science and Technology, 2016Co-Authors: Hawal Rashid, Vincent Desmaris, Victor Belitsky, Marcel Ruf, Thilo Bednorz, Andreas HenkelAbstract:We present a design and synthesis procedure for a new 90 ° waveguide hybrid with ultra-low Amplitude Imbalance. This novel hybrid design is based on Reed's multiple branch waveguide hybrid. The primary feature of this quadrature hybrid design is the introduction of a controllable ripple in the operational band by, firstly changing the heights of the input and output branches and, secondly, by introducing three waveguide-height discontinuity sections placed symmetrically in the main waveguide. This layout allows ultra-low Amplitude Imbalance over a wide operational band. At the same time, it permits a greater input/output branch height as compared to the Reed's 5-branch waveguide hybrid, which should ease fabrication for short-mm and sub-mm wavelengths. This design concept is demonstrated through a 90 ° waveguide hybrid for the 159-216 GHz band (30% fractional bandwidth). Our simulations indicate that the Amplitude Imbalance of the hybrid is better than 0.2 dB over the most of the 159-216 GHz band with a phase Imbalance better than ±4°. Experimental verification of the hybrid shows excellent agreement with the simulations.
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Novel Waveguide 3 dB Hybrid With Improved Amplitude Imbalance
IEEE Microwave and Wireless Components Letters, 2014Co-Authors: Hawal Rashid, Denis Meledin, Vincent Desmaris, Victor BelitskyAbstract:We present a new design concept for a 90° waveguide hybrid and its implementation. This novel hybrid design is based on a multiple branch waveguide hybrid. The primary feature of this quadrature waveguide hybrid is the introduction of a controllable ripple in the operational band for achieving a better overall Amplitude Imbalance. This design concept is verified by implementation of a 90° waveguide hybrid for the 166-208 GHz band and can be used for waveguide hybrids up to several THz. Our simulations indicate that the Amplitude Imbalance of the designed hybrid is better than 0.11 dB over the most of the 166-208 GHz band with a phase Imbalance better than ± 2.3°. Experimental verification of the hybrid shows excellent agreement with simulations with an Amplitude Imbalance better than 0.15 dB and phase Imbalance of ± 2.5° over most of the band being achieved.
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Superconducting 4–8 GHz IF Hybrid for Low Noise mm-Wave Sideband Separation SIS Receiver
IEEE Microwave and Wireless Components Letters, 2012Co-Authors: Bhushan Billade, Hawal Rashid, Vincent Desmaris, Victor BelitskyAbstract:We present the design and performance of a superconducting 90° hybrid covering a full octave bandwidth from 4 to 8 GHz. The hybrid is designed using the Lange coupler layout. The novel features of this quadrature hybrid include superconducting niobium (Nb) transmission lines, air bridges to connect the fingers of the coupler and a bias-T integrated with the coupler. Our simulations indicate that the Amplitude Imbalance of the designed hybrid is less than 0.8 dB over the entire 4-8 GHz band with negligible phase Imbalance. Experimental verification of the hybrid at 4 K, shows very good agreement between the simulations and the measurement results. The measured Amplitude Imbalance of the hybrid is less than 0.8 dB over 98% of the band and the maximum phase Imbalance is ±4 degrees.
Victor Belitsky - One of the best experts on this subject based on the ideXlab platform.
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Wideband Planar Hybrid With Ultralow Amplitude Imbalance
IEEE Microwave and Wireless Components Letters, 2017Co-Authors: Hawal Rashid, Parisa Yadranjee Aghdam, Denis Meledin, Vincent Desmaris, Victor BelitskyAbstract:We present a new design approach for the 90° directional coupler with very low Amplitude Imbalance. The primary feature of this quadrature coupler is the introduction of a controllable ripple in the operational band for achieving a better overall Amplitude balance. This design concept is demonstrated through a 90° branch-line hybrid for the 4–7.9 GHz band (65% fractional bandwidth) using microstrip transmission lines. Our simulations indicate that the Amplitude Imbalance of the designed hybrid is better than 0.3 dB over the most of the 4–7.9 GHz band with a phase Imbalance better than ±8.5°. Experimental verification of the hybrid shows excellent agreement with simulations.
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Design of Wideband Waveguide Hybrid With Ultra-Low Amplitude Imbalance
IEEE Transactions on Terahertz Science and Technology, 2016Co-Authors: Hawal Rashid, Vincent Desmaris, Victor Belitsky, Marcel Ruf, Thilo Bednorz, Andreas HenkelAbstract:We present a design and synthesis procedure for a new 90 ° waveguide hybrid with ultra-low Amplitude Imbalance. This novel hybrid design is based on Reed's multiple branch waveguide hybrid. The primary feature of this quadrature hybrid design is the introduction of a controllable ripple in the operational band by, firstly changing the heights of the input and output branches and, secondly, by introducing three waveguide-height discontinuity sections placed symmetrically in the main waveguide. This layout allows ultra-low Amplitude Imbalance over a wide operational band. At the same time, it permits a greater input/output branch height as compared to the Reed's 5-branch waveguide hybrid, which should ease fabrication for short-mm and sub-mm wavelengths. This design concept is demonstrated through a 90 ° waveguide hybrid for the 159-216 GHz band (30% fractional bandwidth). Our simulations indicate that the Amplitude Imbalance of the hybrid is better than 0.2 dB over the most of the 159-216 GHz band with a phase Imbalance better than ±4°. Experimental verification of the hybrid shows excellent agreement with the simulations.
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Novel Waveguide 3 dB Hybrid With Improved Amplitude Imbalance
IEEE Microwave and Wireless Components Letters, 2014Co-Authors: Hawal Rashid, Denis Meledin, Vincent Desmaris, Victor BelitskyAbstract:We present a new design concept for a 90° waveguide hybrid and its implementation. This novel hybrid design is based on a multiple branch waveguide hybrid. The primary feature of this quadrature waveguide hybrid is the introduction of a controllable ripple in the operational band for achieving a better overall Amplitude Imbalance. This design concept is verified by implementation of a 90° waveguide hybrid for the 166-208 GHz band and can be used for waveguide hybrids up to several THz. Our simulations indicate that the Amplitude Imbalance of the designed hybrid is better than 0.11 dB over the most of the 166-208 GHz band with a phase Imbalance better than ± 2.3°. Experimental verification of the hybrid shows excellent agreement with simulations with an Amplitude Imbalance better than 0.15 dB and phase Imbalance of ± 2.5° over most of the band being achieved.
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Superconducting 4–8 GHz IF Hybrid for Low Noise mm-Wave Sideband Separation SIS Receiver
IEEE Microwave and Wireless Components Letters, 2012Co-Authors: Bhushan Billade, Hawal Rashid, Vincent Desmaris, Victor BelitskyAbstract:We present the design and performance of a superconducting 90° hybrid covering a full octave bandwidth from 4 to 8 GHz. The hybrid is designed using the Lange coupler layout. The novel features of this quadrature hybrid include superconducting niobium (Nb) transmission lines, air bridges to connect the fingers of the coupler and a bias-T integrated with the coupler. Our simulations indicate that the Amplitude Imbalance of the designed hybrid is less than 0.8 dB over the entire 4-8 GHz band with negligible phase Imbalance. Experimental verification of the hybrid at 4 K, shows very good agreement between the simulations and the measurement results. The measured Amplitude Imbalance of the hybrid is less than 0.8 dB over 98% of the band and the maximum phase Imbalance is ±4 degrees.
Quan Xue - One of the best experts on this subject based on the ideXlab platform.
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Planar Reconfigurable Balanced Rat-Race Coupler With Improved Amplitude Imbalance Performance and Common-Mode Noise Absorption
IEEE Transactions on Microwave Theory and Techniques, 2020Co-Authors: Xiangguan Tan, Feng Lin, Houjun Sun, Quan XueAbstract:In this article, the design method for absorptive balanced rat-race couplers with reconfigurable power-dividing ratio is proposed for the first time. First, the differential-mode (DM) and common-mode (CM) port equivalent impedances of the eight-port balanced network is derived by the even–odd mode method under the mixed-mode isolation and matching conditions. The power-dividing ratio is tuned by changing the admittance ratio of the network components, which greatly extends the Amplitude Imbalance bandwidth. Then, a nonabsorptive reconfigurable balanced rat-race coupler that consists of transmission lines with adjustable characteristic impedance is proposed. Furthermore, based on the derived DM and CM port equivalent impedances, an absorptive network is designed. Finally, the absorptive reconfigurable balanced rat-race coupler is achieved by attaching the absorptive network at the balanced ports of the designed nonabsorptive reconfigurable balanced rat-race coupler. For verification, the 2-GHz nonabsorptive and absorptive reconfigurable balanced rat-race couplers are designed and measured. The measured results agree well with the simulations. For the nonabsorptive coupler, the measured power-dividing ratio is tuned from −8.5 to 8.9 dB, while the 15-dB DM matching and isolation bandwidth is greater than 370 MHz. For the absorptive coupler, the measured power-dividing ratio is tuned from −8.3 to 9.0 dB, while the 15-dB DM matching and isolation bandwidth and 15-dB CM matching bandwidth are greater than 450 and 1150 MHz, respectively. The measured 0.5-dB Amplitude Imbalance bandwidths of the nonabsorptive and absorptive couplers are 6%–14.5% and 7%–15.6%, respectively.
Abdel-razik Sebak - One of the best experts on this subject based on the ideXlab platform.
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Wideband Printed Ridge Gap Rat-Race Coupler for Differential Feeding Antenna
IEEE Access, 2020Co-Authors: Islam Afifi, Abdel-razik SebakAbstract:In this paper, a wideband 3 dB hybrid 180° rat-race coupler is introduced in the printed ridge gap waveguide technology. It has simultaneous wide matching and isolation bandwidth with low output Amplitude Imbalance. It operates in the millimeter wave band from 25.8 to 34.2 GHz (27.96%) with 15 dB return loss and isolation, and ±0.5 dB output Amplitude Imbalance. The proposed design employing an open stub at the middle of the $3 \lambda /4$ branch line and quarter wavelength lines at all the ports of the coupler. The objective of the added open stub is to separate the output ports Amplitudes around the -3 dB level by certain values depending on the required Amplitude Imbalance. The analytical derivation for the role of the added open stub is presented along with a parametric study on its effect on Amplitude Imbalance, matching, and isolation. This results in having two intersection points for the output ports instead of one of the conventional coupler and hence the Amplitude Imbalance bandwidth increases. The objective of the added quarter wavelength lines is to improve the matching and isolation bandwidths. First, the conventional rat-race coupler is presented and a bandwidth of 14.25% at 30 GHz is achieved. After that the rat-race with the added quarter wavelength lines is presented to illustrate the objective of the added quarter wavelength lines and a bandwidth of 19.44% is achieved. Finally, the rat-race with the quarter wavelength lines and the added stub is presented and a prototype is fabricated and measured. The s-parameters measurements are in a good agreement with the simulated ones.
Andreas Henkel - One of the best experts on this subject based on the ideXlab platform.
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Design of Wideband Waveguide Hybrid With Ultra-Low Amplitude Imbalance
IEEE Transactions on Terahertz Science and Technology, 2016Co-Authors: Hawal Rashid, Vincent Desmaris, Victor Belitsky, Marcel Ruf, Thilo Bednorz, Andreas HenkelAbstract:We present a design and synthesis procedure for a new 90 ° waveguide hybrid with ultra-low Amplitude Imbalance. This novel hybrid design is based on Reed's multiple branch waveguide hybrid. The primary feature of this quadrature hybrid design is the introduction of a controllable ripple in the operational band by, firstly changing the heights of the input and output branches and, secondly, by introducing three waveguide-height discontinuity sections placed symmetrically in the main waveguide. This layout allows ultra-low Amplitude Imbalance over a wide operational band. At the same time, it permits a greater input/output branch height as compared to the Reed's 5-branch waveguide hybrid, which should ease fabrication for short-mm and sub-mm wavelengths. This design concept is demonstrated through a 90 ° waveguide hybrid for the 159-216 GHz band (30% fractional bandwidth). Our simulations indicate that the Amplitude Imbalance of the hybrid is better than 0.2 dB over the most of the 159-216 GHz band with a phase Imbalance better than ±4°. Experimental verification of the hybrid shows excellent agreement with the simulations.
