CST算法理論

CST軟件產(chǎn)品（馬飛亞、微波工作室和電磁工作室）均采用的是一個(gè)算法，即有限積分技術(shù)（Finite Integration Technique －FIT)。
FIT是一套完備的數(shù)學(xué)理論，是麥克斯韋積分方程在網(wǎng)格空間上的離散形式。早在1977年由托馬斯.魏蘭特教授(Prof. Thomas Weiland)引入，進(jìn)而成為其后在電磁仿真領(lǐng)域中一個(gè)重要算法的基石。由FIT所導(dǎo)出的矩陣方程保持了解析麥克斯韋方程各種固有的特性，如：電荷守恒性和能量守恒性。解析下的梯度、散度和旋度算子在FIT下具有一一對(duì)應(yīng)的矩陣。這些矩陣滿足解析形式下的算子恒等式。故FIT保證了非常好的數(shù)值收斂性。另一個(gè)區(qū)別于其他算法的關(guān)鍵之處在于FIT可被用于所有頻段的電磁仿真問(wèn)題中。
以下是一些具有代表性的有關(guān)有限積分技術(shù)的參考文獻(xiàn)：

[tr]1.[td]T. Weiland, A Discretization Method for the Solution of Maxwell`s Equations for Six-Component Fields. Electronics and Communication (AEÜ), vol. 31, no. 3, pp. 116-120, 1977[tr]2.[td]U. van Rienen and T. Weiland, Triangular discretization method for the evaluation of RF-Fields in cylindrically symmetric cavities, IEEE Transactions on Magnetics, vol. MAG-21, no. 6, pp.2317-2320, 1985.[tr]3.[td]T. Weiland, Time domain electromagnetic Field computation with Finite Difference Methods, International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, vol.9, pp. 259-319, 1996[tr]4.[td]R. Schuhmann, M. Clemens, P. Thoma, T. Weiland, Frequency and Time Domain Computations of S-Parameters Using the Finite Integration Technique, Proc. of the 12th Annual Review of Progress in Applied Computational Electromagnetics (ACES Conference), Monterey, 1996, pp. 1295-1302[tr]5.[td]M. Clemens, R. Schuhmann, T. Weiland, Algebraic Properties and Conservation Laws in the Discrete Electromagnetism, FREQUENZ, Band 53 (1999) , Ausg. 11-12, S. 219 - 225[tr]6.[td]R. Schuhmann and T. Weiland, Conservation of discrete energy and related laws in the Fnite Integration Technique, submitted to the Journal of Electromagnetic Waves and Applications, Special volume on "Geometrical Methods in Computational Electromagnetics" of the PIER monograph series, 2000

在CST微波工作室和電磁工作室中，我們還引入了CST的專有技術(shù)－理想邊界擬合（Perfect Boundary Approximation － PBA)。它使得長(zhǎng)方形網(wǎng)格中材料的填充形式可以任意（單連通或復(fù)連通）。由于此技術(shù)，CST軟件不但保持了通常FDTD的快速，而且還使其精度大為提高。即，帶PBA的FIT即快又準(zhǔn)。
換言之，對(duì)同一問(wèn)題達(dá)到同一仿真精度而言，微波工作室或電磁工作室較馬飛亞的計(jì)算時(shí)間短。