The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform
Herbert J. Shaw - One of the best experts on this subject based on the ideXlab platform.
-
Large-scale interferometric fiber sensor arrays with multiple optical amplifiers
Optics letters, 1997Co-Authors: Craig W. Hodgson, Michel J. F. Digonnet, Herbert J. ShawAbstract:We report what we believe to be the first laboratory prototype of a fiber sensor array using multiple low-gain (5dB) remotely pumped amplifiers in a 10-rung ladder structure. Incorporating amplifiers improves the System Noise Figure to less than 20dB, compared with 32dB in an optimized passive array of the same size. Scalability to more than 300sensors per fiber pair while a high dynamic range (1microrad/ sensitivity) is maintained is demonstrated.
-
Novel fiber sensor arrays using erbium-doped fiber amplifiers
Journal of Lightwave Technology, 1997Co-Authors: Jefferson L. Wagener, Craig W. Hodgson, Michel J. F. Digonnet, Herbert J. ShawAbstract:We examine the signal-to-Noise ratio (SNR) performance of a novel type of time domain multiplexed sensor arrays in which low gain (1-10 dB) fiber amplifiers are incorporated to compensate for splitting losses between sensors. The System Noise Figure for passive and amplified sensor arrays is presented, along with expressions to optimize the array parameters for high SNRs. We show that practical amplified sensor arrays exhibit low System Noise Figures that allow much larger arrays (hundreds of sensors) than passive arrays.
Gabriel M. Rebeiz - One of the best experts on this subject based on the ideXlab platform.
-
A High-Linearity 76–85-GHz 16-Element 8-Transmit/8-Receive Phased-Array Chip With High Isolation and Flip-Chip Packaging
IEEE Transactions on Microwave Theory and Techniques, 2014Co-Authors: Bon-hyun Ku, Ozgur Inac, Hyun-ho Yang, Michael Chang, Gabriel M. RebeizAbstract:An SiGe transmit-receive phased-array chip has been developed for automotive radar applications at 76-84 GHz. The chip is based on an all-RF beamforming approach and contains 8-transmit channels, 8-receive channels, and a complete built-in-self-test System. Two high-linearity quadrature mixers with an input P1 dB of +2.5 dBm are used and allow simultaneous sum and difference patterns in the receive mode. The chip operates in either a narrowband frequency-modulated continuous-wave (FMCW) mode or a wideband mode with > 2-GHz bandwidth. A high-linearity design results in an input P1 dB of -10 dBm (per channel), a System Noise Figure of 16-18 dB, and a transmit power is 4-5 dBm (per channel). The chip uses a controlled collapse chip connection (C4) bumping process and is flip-chipped on a low-cost printed-circuit board, and results in > 50-dB isolation between the transmit and receive chains. To our knowledge, this work represents the state-of-the-art in terms of complexity at millimeter-wave frequencies and with simultaneous transmit and receive operation for high-performance FMCW radars.
-
Improving 3G/4G receiver sensitivity (TIS) using antenna impedance matching networks
2014 IEEE MTT-S International Microwave Symposium (IMS2014), 2014Co-Authors: Hsin-chang Lin, Gabriel M. RebeizAbstract:This paper explores new applications for antenna impedance matching networks. It is seen that a tunable matching network can improve the cell phone System Noise Figure and total integrated sensitivity (TIS) by at ~ 1 dB at 700 MHz - 3 GHz. The reason is that a mismatched low-Noise amplifier has a higher Noise Figure and a lower gain than a Noise-matched LNA, and therefore, a tunable matching network is important for Noise matching in receiver applications. This would lead to shorter download times and more efficient 3G and 4G mobile networks.
-
A 76–84-GHz 16-Element Phased-Array Receiver With a Chip-Level Built-In Self-Test System
IEEE Transactions on Microwave Theory and Techniques, 2013Co-Authors: Sang Young Kim, Ozgur Inac, Choul-young Kim, Donghyup Shin, Gabriel M. RebeizAbstract:This paper presents a 16-element phased-array receiver for 76-84-GHz applications with built-in self-test (BIST) capabilities. The chip contains an in-phase/quadrature (I/Q) mixer suitable for automotive frequency-modulation continuous-wave radar applications, which is also used as part of the BIST System. The chip achieves 4-bit RF amplitude and phase control, an RF to IF gain of 30-35 dB at 77-84 GHz, I/Q balance of and at 76-84 GHz, and a System Noise Figure of 18 dB. The on-chip BIST covers the 76-84-GHz range and determines, without any calibration, the amplitude and phase of each channel, a normalized frequency response, and can measure the gain control using RF gain control. System-level considerations are discussed together with extensive results showing the effectiveness of the on-chip BIST as compared with standard S-parameter measurements.
-
A low-cost 20-22 GHz MIC active receiver/radiometer
1995Co-Authors: S. Mollenkopf, Linda P. B. Katehi, Gabriel M. RebeizAbstract:A microwave integrated circuit active receiver is built and tested at 19-25 GHz. The receiver consists of a planar CPW-fed double folded-slot antenna coupled to a six-stage MESFET amplifier and followed by a planar Schottky-diode detector. The folded-slot antenna on a GaAs half-space results in a wide frequency bandwidth suitable for MMIC amplifiers. The measured System performance show a video responsivity close to 1 GV/W at 20 GHz with a 3-dB bandwidth of 1500 MHz. A novel method which uses the planar video detector after the amplifier stages as an RF mixer is used to measure the Noise-Figure of the direct detection radiometer. The System Noise Figure is 4.8 dB at 22 GHz. The radiometer sensitivity to a hot/cold load is 3.8 μV/K. The measured antenna patterns show a 90% Gaussicity at 20-22 GHz. The active MIC receiver can be integrated monolithically for low-cost applications and is well suited for millimeter-wave linear imaging arrays
Jens Anders - One of the best experts on this subject based on the ideXlab platform.
-
Single-Cycle-PLL Detection for Real-Time FM-AFM Applications
IEEE transactions on biomedical circuits and systems, 2014Co-Authors: Benedikt Schlecker, Maurits Ortmanns, Georg E. Fantner, Maja Dukic, Blake Erickson, Jens AndersAbstract:In this paper we present a novel architecture for phase-locked loop (PLL) based high-speed demodulation of frequency-modulated (FM) atomic force microscopy (AFM) signals. In our approach, we use single-sideband (SSB) frequency upconversion to translate the AFM signal from the position sensitive detector to a fixed intermediate frequency (IF) of 10 MHz. In this way, we fully benefit from the excellent Noise performance of PLL-based FM demodulators still avoiding the intrinsic bandwidth limitation of such Systems. In addition, the upconversion to a fixed IF renders the PLL demodulator independent of the cantilever's resonance frequency, allowing the System to work with a large range of cantilever frequencies. To investigate if the additional Noise introduced by the SSB upconverter degrades the System Noise Figure we present a model of the AM-to-FM Noise conversion in PLLs incorporating a phase-frequency detector. Using this model, we can predict an upper corner frequency for the demodulation bandwidth above which the converted Noise from the single-sideband upconverter becomes the dominant Noise source and therefore begins to deteriorate the overall System performance. The approach is validated by both electrical and AFM measurements obtained with a PCB-based prototype implementing the proposed demodulator architecture.
-
ISCAS - PLL-based high-speed demodulation of FM signals for real-time AFM applications
2013 IEEE International Symposium on Circuits and Systems (ISCAS2013), 2013Co-Authors: Benedikt Schlecker, Maurits Ortmanns, Jens Anders, Georg E. FantnerAbstract:In this paper we present a new architecture for PLL-based high-speed demodulation of frequency-modulated AFM signals. In our approach, we use single-sideband frequency up-conversion to translate the AFM signal from the position sensitive detector to a fixed intermediate frequency of 10 MHz. In this way, we fully benefit from the excellent Noise performance of PLL-based FM demodulators still avoiding the intrinsic bandwidth limitation of such Systems. Furthermore, the System becomes independent of the cantilever's resonance frequency. To investigate if the additional Noise introduced by the single-sideband upconverter degrades the System Noise Figure we present a model of the AM-to-FM Noise conversion in the PLL phase detector. Using this model, we can predict an upper corner frequency for the demodulation bandwidth above which the converted Noise from the single-sideband upconverter becomes the dominant Noise source and therefore begins to deteriorate the overall System performance. The approach is validated by measured data obtained with a PCB-based prototype implementing the proposed demodulator architecture.
Craig W. Hodgson - One of the best experts on this subject based on the ideXlab platform.
-
Large-scale interferometric fiber sensor arrays with multiple optical amplifiers
Optics letters, 1997Co-Authors: Craig W. Hodgson, Michel J. F. Digonnet, Herbert J. ShawAbstract:We report what we believe to be the first laboratory prototype of a fiber sensor array using multiple low-gain (5dB) remotely pumped amplifiers in a 10-rung ladder structure. Incorporating amplifiers improves the System Noise Figure to less than 20dB, compared with 32dB in an optimized passive array of the same size. Scalability to more than 300sensors per fiber pair while a high dynamic range (1microrad/ sensitivity) is maintained is demonstrated.
-
Novel fiber sensor arrays using erbium-doped fiber amplifiers
Journal of Lightwave Technology, 1997Co-Authors: Jefferson L. Wagener, Craig W. Hodgson, Michel J. F. Digonnet, Herbert J. ShawAbstract:We examine the signal-to-Noise ratio (SNR) performance of a novel type of time domain multiplexed sensor arrays in which low gain (1-10 dB) fiber amplifiers are incorporated to compensate for splitting losses between sensors. The System Noise Figure for passive and amplified sensor arrays is presented, along with expressions to optimize the array parameters for high SNRs. We show that practical amplified sensor arrays exhibit low System Noise Figures that allow much larger arrays (hundreds of sensors) than passive arrays.
Georg E. Fantner - One of the best experts on this subject based on the ideXlab platform.
-
Single-Cycle-PLL Detection for Real-Time FM-AFM Applications
IEEE transactions on biomedical circuits and systems, 2014Co-Authors: Benedikt Schlecker, Maurits Ortmanns, Georg E. Fantner, Maja Dukic, Blake Erickson, Jens AndersAbstract:In this paper we present a novel architecture for phase-locked loop (PLL) based high-speed demodulation of frequency-modulated (FM) atomic force microscopy (AFM) signals. In our approach, we use single-sideband (SSB) frequency upconversion to translate the AFM signal from the position sensitive detector to a fixed intermediate frequency (IF) of 10 MHz. In this way, we fully benefit from the excellent Noise performance of PLL-based FM demodulators still avoiding the intrinsic bandwidth limitation of such Systems. In addition, the upconversion to a fixed IF renders the PLL demodulator independent of the cantilever's resonance frequency, allowing the System to work with a large range of cantilever frequencies. To investigate if the additional Noise introduced by the SSB upconverter degrades the System Noise Figure we present a model of the AM-to-FM Noise conversion in PLLs incorporating a phase-frequency detector. Using this model, we can predict an upper corner frequency for the demodulation bandwidth above which the converted Noise from the single-sideband upconverter becomes the dominant Noise source and therefore begins to deteriorate the overall System performance. The approach is validated by both electrical and AFM measurements obtained with a PCB-based prototype implementing the proposed demodulator architecture.
-
ISCAS - PLL-based high-speed demodulation of FM signals for real-time AFM applications
2013 IEEE International Symposium on Circuits and Systems (ISCAS2013), 2013Co-Authors: Benedikt Schlecker, Maurits Ortmanns, Jens Anders, Georg E. FantnerAbstract:In this paper we present a new architecture for PLL-based high-speed demodulation of frequency-modulated AFM signals. In our approach, we use single-sideband frequency up-conversion to translate the AFM signal from the position sensitive detector to a fixed intermediate frequency of 10 MHz. In this way, we fully benefit from the excellent Noise performance of PLL-based FM demodulators still avoiding the intrinsic bandwidth limitation of such Systems. Furthermore, the System becomes independent of the cantilever's resonance frequency. To investigate if the additional Noise introduced by the single-sideband upconverter degrades the System Noise Figure we present a model of the AM-to-FM Noise conversion in the PLL phase detector. Using this model, we can predict an upper corner frequency for the demodulation bandwidth above which the converted Noise from the single-sideband upconverter becomes the dominant Noise source and therefore begins to deteriorate the overall System performance. The approach is validated by measured data obtained with a PCB-based prototype implementing the proposed demodulator architecture.
