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linearisation technique for low-voltage tuneable Nauta's transconductor in G_m-C filter design

IET CIRCUITS DEVICES & SYSTEMS 2018年第4期12卷 347-361页

作者： Khumsat, Phanumas Prince Songkla Univ Fac Engn Dept Elect Engn Hat Yai 90112 Songkhla Thailand

A low-distortion, low-voltage transconductor based on Nauta's inverter-type transconductor is proposed. The transconductor's core MOSFETs are pushed into a strong inversion region under a low-voltage supply utilizing a level shifter consisting of a linear resistor and a MOSFET current source. The transconductor's linearization relies on summing a decreasing G(m) characteristic with an increasing counterpart to obtain an overall flat G(m) characteristic. The non-ideal decreasing G(m) is exploited from a non-linear behaviour of the triode-MOS current source that restricts a |V-GS| increment of the core strongly-inverted MOSFET quartet while its increasing-G(m) counterpart found in another weakly-inverted auxiliary MOSFET quartet. The MOSFET current source plays significant role in the linearization process where it has to be in a triode mode of either a strong, weak or moderate inversion region. Simulation results are provided to verify the feasibility of the proposed transconductor with a 5th-order Chebyshev lowpass filter in a 0.18 mu m CMOS process. The filter operates under a 0.5V supply (the ratio V-DD/V-TH=1.19) with a continuous bandwidth tuning from 500kHz to 2.8MHz. The proposed filter with a nominal 1.4MHz bandwidth and a 430mW power consumption renders the two-tone SFDR of 64.9dB.

关键词： low-pass filters Chebyshev filters linearisation techniques invertors MOSFET circuits triodes constant current sources Monte Carlo methods CMOS integrated circuits bandwidth 1 4 MHz power 430 muW frequency 500 kHz to 2 8 MHz voltage 0 5 V size 0 18 mum total harmonic distortion two-tone spurious-free dynamic range power consumption continuous bandwidth tuning CMOS process fifth-order Chebyshev lowpass filter corner analyses Monte-Carlo analysis post-layout simulation inverted MOSFET quartet triode-MOS current source nonlinear behaviour tunable MOS current source passive linear resistor voltage level shifter low supply voltage strong inversion region transconductor core MOSFETs G(m)-C filter design low-distortion low-voltage tuneable Nauta inverter-type transconductor linearisation technique

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A note on integrated disassembly line balancing and routing problem

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INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH 2023年第9期61卷 3144-3150页

作者： Feng, Jianguang Che, Ada Northwestern Polytech Univ Sch Management Xian 710072 Peoples R China

This note comments on the study of [Diri Kenger, Zulal, cagri Koc, and Eren ozceylan. 2020. "Integrated Disassembly Line Balancing and Routing Problem." International Journal of Production Research 58 (23): 7250-7268.] which studies an integrated disassembly line balancing and routing problem and develops two mixed integer linear programming (MILP) models and three mixed integer nonlinear programming (MINLP) models to handle five different scenarios, respectively. The purpose is twofold. First, we demonstrate that the two MILP models can be separated into two parallel subproblems whose optimal solutions can be combined to obtain the optimal solution of the original models. Second, we show that the three MINLP models can be linearised and propose two different linearisation techniques to reformulate them as equivalent MILP models. Computational results indicate that the linearised model outperforms the original nonlinear model in most cases.

关键词： Disassembly line balancing vehicle routing problem nonlinear programming linearisation technique mixed integer linear programming

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Kalman filtering method for sparse off-grid angle estimation for bistatic multiple-input multiple-output radar

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IET RADAR SONAR AND NAVIGATION 2020年第2期14卷 313-319页

作者： Baidoo, Evans Hu, Jurong Zhan, Lei Hohai Univ Coll Comp & Informat Engn Nanjing Jiangsu Peoples R China

In order to address the off-grid angular estimation of direction of departure and direction of arrival of a target for bistatic multiple-input multiple-output radar, a novel method involving the combined effect of compressive sensing theory and an optimal estimation algorithm is proposed. The proposed method, named as simultaneous orthogonal matching pursuit with Kalman filtering (SOMP-KF) first exploit the sparsity of the target in the spatial domain by discretising the area of detection to formulate a dictionary matrix. Sparse sampling created during the discretisation of the off-grid space leads to a remodelling of the problem where a linearisation technique that inculcates a grid-varying position vector is applied to the Kalman filtering method. The modified Kalman filtering method resolves the off-grid offset, which hence results in achieving the off-grid angle estimation objective. Additionally, the Cramer-Rao lower bounds are derived theoretically for all parameters to explain the estimation performance. Experimental analysis against existing methods indicates the proposed SOMP-KF effectiveness in improving the angle estimation of target whiles, maintaining a minimal computational cost than its competitors.

关键词： compressed sensing Kalman filters iterative methods direction-of-arrival estimation linearisation techniques MIMO radar bistatic multiple-input multiple-output radar direction of arrival optimal estimation algorithm orthogonal matching pursuit off-grid space grid-varying position vector modified Kalman filtering sparse off-grid angle estimation compressive sensing dictionary matrix linearisation technique Cramer-Rao lower bounds direction of departure

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Fully integrated fractional-N phase-locked loop for GNSS standards

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IET MICROWAVES ANTENNAS & PROPAGATION 2019年第13期13卷 2391-2395页

作者： Kashani, Zahra Ghattan Avanji, Seyed Amin Izadi KN Toosi Univ Technol Elect Engn Tehran Iran Shahid Sattari Univ Aeronaut Engn Elect Engn Dept Tehran Iran

This study presents the design of a fully integrated fractional-N phase-locked loop (FNPLL) for the Global Navigation Satellite System (GNSS) applications. A new linearisation technique is presented for a charge pump (CP) circuit to improve the mismatch between the charging and discharging currents. The linearised currents help to reduce the static phase offset and the reference spurs of the FNPLL and the constant current helps to control the PLL dynamics precisely. The presented FNPLL is designed in a 0.18 mu m CMOS technology. The simulation result reveals that the linearity of the CP is enhanced greatly when the technique is enabled and the current mismatch is <0.2 mu A over the output voltage ranging from 0.2 to 1.65 V. The phase noise of the FNPLL at 10 and 100 KHz offset frequencies without the linearised CP are -85 and -90 dBc/Hz, respectively, and with the high linear CP are -90 and -97 dBc/Hz, respectively. The output power spectral density of the FNPLL shows that the power of the highest fractional spur is about -57 dBc. The lock time and the power consumption of the designed FNPLL are 50 mu s and 11 mW from a 1.8 V power supply, respectively.

关键词： charge pump circuits phase locked loops phase noise CMOS integrated circuits satellite navigation integrated circuit design linearised currents static phase offset current mismatch phase noise GNSS standards linearisation technique charge pump circuit fully integrated fractional-N phase-locked loop FNPLL CMOS technology reference spurs global navigation satellite system PLL dynamics constant current output power spectral density power consumption fractional spur time 50 0 mus voltage 1 8 V voltage 0 2 V to 1 65 V power 11 0 mW size 0 18 mum

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Expansion planning for active distribution networks considering deployment of smart management technologies

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IET GENERATION TRANSMISSION & DISTRIBUTION 2018年第20期12卷 4605-4614页

作者： Feng, Changsen Liu, Weijia Wen, Fushuan Li, Zhiyi Shahidehpour, Mohammad Shen, Xinwei Zhejiang Univ Sch Elect Engn Hangzhou 310027 Zhejiang Peoples R China IIT Dept Elect & Comp Engn Chicago IL 60605 USA Tsinghua Berkeley Shenzhen Inst Shenzhen 518055 Peoples R China

In this study, a multi-stage long-term expansion planning model for an active distribution network (ADN) is presented, with the aim of minimising the investment and operation cost in a coordinated manner over an established horizon. The planning model optimises the following alternatives: upgrading the capacities of substations, reinforcing and/or constructing cable circuits, placing voltage regulators (VRs) and/or static VAR generators, and determining the connection points for distributed generators (DGs). The investment decisions are optimised over the entire planning horizon which can be further divided into multiple periods, and the operation strategies, e.g. active management of DG as well as ADN topology reconfiguration, are determined according to the profiles of representative scenarios. To relieve the computational burden, the original model is properly simplified as a mixed-integer quadratic constrained programming problem through linearisation and approximation techniques, and the solution optimality is guaranteed after invoking the off-the-shell solver. A 24-node test system is employed to validate the effectiveness of the proposed model.

关键词： power distribution planning distributed power generation power generation planning quadratic programming static VAr compensators integer programming investment power distribution economics power generation economics power system management power cables substations voltage regulators minimisation approximation theory smart management technologies operation cost cable circuits voltage regulators static VAR generators connection points distributed generators investment decisions operation strategies ADN topology reconfiguration mixed-integer quadratic constrained programming problem active distribution networks substation capacity multistage long-term expansion planning model investment minimisation linearisation technique approximation technique 24-node test system

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Cartesian augmented Hammerstein model for non-linearity and I/Q impairments compensation in concurrent dual-band transmitters

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IET COMMUNICATIONS 2017年第13期11卷 1992-1997页

作者： Lajnef, Souhir Boulejfen, Noureddine Ghannouchi, Fadhel M. Univ Tunis El Manar Dept Phys Elect Lab Fac Sci Tunis 2092 Tunisia Ctr Res Microelect & Nanotechnol Technopole Sousse Sousse 4050 Tunisia Univ Calgary Elect Engn Dept IRadio Lab Schulich Engn Sch Calgary AB T2N 1N4 Canada

In this study, a novel model for the joint compensation of dual-band power amplifier (PA) distortion and in-phase/quadrature (I/Q) imbalance, which are the dominant impairments of wireless signal transmitters, in a complexity reduced structure is proposed. This model is mainly based on the augmented Hammerstein approach in a Cartesian form so that a static block is intended to model the PA non-linearity and the modulator I/Q imbalance while a finite impulse response filter based block is used to model the PA memory effects. The proposed approach reduces significantly the complexity of the proposed model compared with the recently published memory polynomial models. Experiments with and without I/Q modulator impairments have been carried out on a dual-band PA to verify the accuracy and the performance of the linearisation technique based on the proposed model. The experimental results have revealed a good impairments reduction with much less model coefficients compared with the recently published ones.

关键词： radio transmitters radiofrequency power amplifiers FIR filters cartesian augmented Hammerstein model I-Q impairment compensation nonlinearity compensation concurrent dual-band transmitters dual-band power amplifier distortion compensation in-phase-quadrature imbalance compensation finite impulse response filter PA memory effects memory polynomial model linearisation technique wireless communication system

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Payment minimisation auction with security constraints

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IET GENERATION TRANSMISSION & DISTRIBUTION 2017年第6期11卷 1370-1380页

作者： Nouri, Alireza Hosseini, Seyed Hamid Sharif Univ Technol Dept Elect Engn Ctr Excellence Power Syst Management & Control Tehran Iran

Among the different options available for market clearing mechanisms, offer cost minimisation mechanism is being used in most electric power markets. The payments are then calculated based on locational marginal prices (LMPs). The payments can be significantly higher due to the inconsistency of the clearing and pricing mechanisms. Payment cost minimisation (PCM) mechanism which directly minimises the total payment has been recently proposed to solve this issue. In this study, an auction mechanism is proposed for payment to suppliers minimisation (PSM) based on the LMPs instead of consumers payment minimisation (CPM). Using a proper formulation for the supply side reserve LMPs, the complete reserve problem is included in the proposed joint energy and multi-type reserve PSM auction. The formulation is linearised and solved using a standard branch and cut solver. Since the justifiable reserve marginal prices cannot be found at demand side, as will be discussed, and due to the many advantages of PSM mechanism over CPM mechanism, the objective function is fully calculated at the supply side. This causes some difficulties in the linearisation of the formulation which are solved using proper linearisation techniques. Different case studies are conducted and the results of different mechanisms are compared.

关键词： power system security minimisation power markets pricing power system economics demand side management linearisation techniques demand side linearisation technique branch and cut solver joint energy-multitype reserve PSM auction PSM payment to supplier minimisation PCM mechanism pricing mechanism LMP locational marginal price electric power market cost minimisation mechanism market clearing mechanism security constraint payment minimisation auction

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Mid-term vulnerability analysis of power systems under intentional attacks

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IET GENERATION TRANSMISSION & DISTRIBUTION 2016年第15期10卷 3745-3755页

作者： Sayyadipour, Saeed Yousefi, Gholam Reza Latify, Mohammad Amin Isfahan Univ Technol Dept Elect & Comp Engn Esfahan *** Iran

This study addresses the vulnerability analysis of power systems over a time horizon. The authors introduce a model which could be used by system operators to assess where and when, over a specific time horizon, their power systems are most vulnerable to intentional attacks. This new time-phased vulnerability analysis is modelled as a bilevel programming problem in which in the upper level, an attacker determines the best attack plan, including the best locations and the best times over the time horizon, for launching attacks. In the lower level, the system operator minimises the system operation and load shedding costs. Using duality theory, the bilevel optimisation problem is converted into a mathematical programming with equilibrium constraints which is subsequently converted to a single-level mixed integer linear programming problem by means of linearisation techniques. This model is tested on modified Garver 6-bus test system, modified IEEE 24-bus reliability test system, and IEEE 300-bus test system. The results appreciate the capability of the proposed model and show that it is indispensable to consider the time in analysing the vulnerability of power systems.

关键词： integer programming linear programming minimisation power system economics load shedding IEEE standards power system mid-term vulnerability analysis intentional attacks time horizon time-phased vulnerability analysis bilevel programming problem load shedding cost minimisation operation cost minimisation duality theory bilevel optimisation problem mathematical programming single-level mixed integer linear programming problem linearisation technique modified Garver 6-bus test system modified IEEE 24-bus reliability test system IEEE 300-bus test system

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Robust probabilistic optimal voltage sag monitoring in presence of uncertainties

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IET GENERATION TRANSMISSION & DISTRIBUTION 2016年第16期10卷 4240-4248页

作者： Nasiri, Saeed Seifi, Hossein Tarbiat Modares Univ Dept Elect Engn Tehran Iran

This study presents an optimisation model to achieve an optimal voltage sag monitoring programme. To cover the main uncertainty associated with fault impedance, a novel approach termed as probabilistic monitor reach area (PMRA) is developed. Moreover, PMRA is employed to consider reliability of the monitoring equipment impact. Additionally, several indices based on PMRA are defined to distinguish the optimal programme when outage of generators, loading level, line outage and feeder reconfiguration may result in several programmes. Besides, the other advantage of the proposed method is aptitude of modelling large load switching as an influential source of voltage sags. The model determines the number and the location of monitors in such a way that a pre-defined probability of observability is satisfied. Capability of the proposed methodology is checked for several test systems and illustrated here on the 24-bus reliability test system and on the 34-node test feeder. Numerical results and their comparison with the commonly used MRA method reveal that the proposed optimal voltage sag monitoring programme is robust against uncertainties including fault impedance, load variations and outage of the generators/lines.

关键词： power supply quality integer programming nonlinear programming electric impedance observability power system measurement power system reliability linearisation techniques load (electric) probability power system faults uncertain systems robust probabilistic optimal voltage sag monitoring optimisation model fault impedance probabilistic monitor reach area PMRA monitoring equipment impact reliability generator outage loading level line outage feeder reconfiguration large load switching modelling observability mixed integer nonlinear programming problem linearisation technique 24-bus reliability test system 34-node test feeder uncertainty robustness load variations

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Improvement on linearity with iterative calibration technique for multilevel LINC transmitters

Improvement on linearity with iterative calibration techniqu...

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IEEE MTT-S International Microwave Symposium (IMS)

作者： Guan, Junqing Nghiem, Xuan Anh Aref, Ahmed Farouk Negra, Renato Rhein Westfal TH Aachen Fac Elect Engn & Informat Technol Chair High Frequency Elect Aachen Germany

ISBN: (纸本)9781479938698

This paper proposes an iterative calibration technique to enhance the linearity for multilevel LINC transmitters. With this approach, the precision of characterising AM/AM and AMIPM behaviours for discrete levels can be improved, which results in better adjacent channel leakage ratio (ACLR) and error vector magnitude (EVM) performance. An ML-LINC transmitter is built with two PAs in GaN technology, which delivers 40.8 dBm output power with 68% drain efficiency at 2.05 GHz. Up to 5 dB ACLR improvement can be observed by iterative calibration using S1/S2 for a 5 MHz LTE signals. The configuration with 16 levels can give satisfying linearity performance to meet the standard specification, while keep the complexity reasonable. Measurement results show an ACLR of -46 dBc, EVM of 1.9% (QPSK) and 4.2% (64-QAM) at average output power of 35.7 dBm with 51.1 % drain efficiency for a 10 MHz LTE signals with a PAPR of 7.9 dB. The performance of the built ML-LINC tranmitter is compared to the state-of-the-art. Both the linearity and drain efficiency are quite competitive.

关键词： Transmitter LTE Power Amplifier Iterative Calibration linearisation technique LTE Outphasing LINC PA Modeling

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