共查询到8条相似文献,搜索用时 0 毫秒
1.
By using the time modulation technique in antenna arrays, the stringent requirements on excitation error tolerance can be relaxed. However, the sideband signals spaced at multiples of the modulation frequency need to be suppressed in some applications. Multiobjective optimization is an important tool in the design of arrays with conflicting goals, such as low sidelobe level, low sideband level, and narrow beamwidth in the time‐modulated antenna arrays. In this paper, a novel multiobjective evolutionary algorithm based on objective decomposition (MOEA/D) with differential evolution operator and objective normalization technique is employed for the time‐modulated array synthesis, which is typically a problem with disparately scaled conflicting objectives. The effectiveness of the method is demonstrated by comparing the performances obtained by MOEA/D with those of previously reported results obtained by a single‐objective differential evolution algorithm and simulated annealing technique. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
2.
3.
马骥祥 《国外电子测量技术》2008,27(5):36-39
低噪声放大器(简称低噪放)是射频接收前端中的重要部件。设计性能优良的低噪声放大器能够极大的提高通信系统接收机灵敏度和通信质量。本文对微波放大电路的设计方法进行了探讨,并在ADS软件界面上进行了微波窄带滤波器低噪声放大器的优化设计。 相似文献
4.
S. Di Pascoli L. Fanucci B. Neri D. Zito 《International Journal of Circuit Theory and Applications》2003,31(4):351-360
A new topology of bipolar low noise amplifier (LNA) for RF applications, named base coupled differential (BCD), is presented. The proposed approach is compared by simulation against most classical topologies. The BCD configuration has the key advantage to join an integrated matching on a single‐ended input with a differential output. This is done by using down‐bond wiring, so that no integrated inductors are needed. The main advantages of this new topology are a drastic area reduction and an increased linearity range (or a reduced biasing current with the same linearity) together with a noise figure (NF) and voltage supply reduction. Particularly, the BCD LNA presented in this paper has been designed for 2.44GHz frequency operation. It is characterized by a NF of 1.93dB, a voltage gain (Av) of 19.5dB, an input impedance of 50Ωa third Input‐referred Intercept Point (IIP3) of ‐7.25dBm and a dissipated power (PD) equal to 19mW. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
5.
In this paper, we have successfully developed an intellectual parameter‐extraction methodology on the basis of a genetic algorithm (GA), involving the efficient search‐space separation and local‐minima‐convergence prevention schemes. Via an evolutionary simulation tool complemented with appropriate analytic equations, the enhanced approach has been applied to determine the significant figures‐of‐merit (FoMs), including internal quantum efficiency (ηi) as well as transparency current density (Jtr) of semiconductor lasers, minimum noise figure (NFmin) as well as associated available gain (GA,assoc) of low‐noise amplifiers (LNAs), and DC as well as AC characteristics of heterojunction bipolar transistors (HBTs). For the first time, demonstrated FoM‐extraction results, which coincide well with the actually measured data, for state‐of‐the‐art InGaAs quantum‐well lasers, advanced SiGe LNAs, and abrupt ZnSe/Ge/GaAs HBTs are simultaneously presented to validate this multi‐parameter analysis and robust optimization. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
6.
Filiz Güne Salih Demirel Peyman Mahouti 《International Journal of Numerical Modelling》2016,29(1):4-20
In this work, a simple, efficient and multi objective Honey Bee Mating Optimization (HBMO) is presented for the performance characterization of a microwave transistor to deliver maximum power to the load with the required noise Freq. Thus all the possible compatible {Freq ≥ Fmin, Vout = 1, GTmax} triplets and the corresponding source ZS and load ZL = Z*out (ZS) terminations can be obtained in the device operation domain of (VDS, IDS and f) without working analytically for the nonlinear performance and stability equations. HBMO is a recently emerging meta‐heuristic algorithm that combines the powers of the simulated annealing and genetic algorithms. Here, a microwave transistor is chosen as a case study, effectiveness and efficiency of the HBMO are shown by comparing its performance to those of the standard meta‐heuristics Genetic and Particle Swarm algorithms and the mean cost results for 10 runs are found to be 0.22, 1.65 and 1.85, respectively, for the comparable execution times. Furthermore, all the numerical results are found to agree with their analytical counterparts obtained using the microwave, linear circuit and noise theories. The Feasible Design Target Space FDTS can be built by the cross relations among all the possible compatible {Freq ≥ Fmin, Vout = 1, GTmax} triplets together their terminations {ZS, ZL = Z*out (ZS)} covering all the possible amplifier designs where both noise figure and output power are at a premium. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
7.
Mingming Lu Hao Wang Dongpo Zhao Jieqiong Lin Yan Gu Allen Yi 《International Journal of Adaptive Control and Signal Processing》2019,33(7):1066-1078
Vibration‐assisted swing cutting (VASC) is a new precision machining technology. VASC not only inherits the characteristics of EVC intermittent cutting but also alleviates the problem of EVC residual height. However, system identification is key if you want to achieve precise control. In order to solve this problem, a new improved differential evolutionary (IDE) algorithm is proposed to identify and optimize the Hammerstein‐Wiener model parameter in VASC system. IDE algorithm is applied to transform the identification problem of the model into the optimization problem in the parameter space, and the optimal solution of the parameter of the model in the parameter space is obtained. Meanwhile, the IDE algorithm and the conventional five differential evolutionary algorithms perform performance comparison tests on six different test functions. The test results show that the IDE algorithm is strengthening the global search capability, accelerate the convergence rate to the global optimal solution, and indicate that the IDE algorithm can be effectively applied to the parameter optimization of Hammerstein‐winner model. Based on the input and output data collected from the experiment, the accuracy of the identification model can be up to 98%, which prove the superiority of the proposed IDE algorithm for system identification. 相似文献