Thirdly , one numerical stimulation method - fdtd ( fmite - difference time - domain ) and the transformation of near zone to far zone are introduced , and then the program is verified 接着介绍了时域有限差分法( fdtd )及其近场到远场的变换公式,并对自编的fdtd计算程序进行了验证。
Using the simulation program , far zone radiation of tem - horn array is analyzed . the result of analysis proved that the mutual coupling between elements of array did not affect the main radiation wave of very much 应用这一模拟程序,分析了tem喇叭天线阵列轴上远场辐射,分析表明阵元间互耦对阵列轴上远场主辐射波形影响不大。
In order to validate the feasibility of the novel algorithm , ultrawide band pulse wave is used as incident wave . computational domains are limited by absorbing boundary condition . the transformation technique from near zone to far zone is used when the sampling spot is outside of the computational domains 时域成像技术以超宽带脉冲源作为入射波源,用吸收边界条件来界定计算域,而当采样点远离计算区域时,需要通过近?远场的转换技术把近场等效面上的信息转换到远场,本文采用简单而实用的柱面波外推法作为近?远场的转换方法,收到了较好的效果。
The conformal microstrip antenna with some unique character has been applied in many fields , especialy on speedy objects . in this paper , an efficient fdtd algorithm is introduced to analyse the microstrip antenna . firstly , the fdtd formula in descartes coordinate system and in cylindrical coordinate system are obtained from the time _ dependent maxwell equations using the yee algorithm in a calculating region where the dielectric parameters are independent of time and space . the choice of the space discretization units and the time discretization interval are discussed which are decided by the accuracy and stability respectively . the shape and setup of the excitation source are discussed too . the excitation source is chosen to be gaussian pulse in shape . secondly , the mur ' s first - order and second - order boundary condition are deduced in cylindrical coordinate system . the methods of transforming radiation fields from near zone to far zone in the frequency domain and in the time domain are presented when fdtd is applied to analyse the characteristics of far zone . finally , three kinds of microstrip antennas are analysed . they are a slot antenna that lies on a plane ground of a microstrip , a slot antenna that lies on a cylindrical ground of a microstrip and a microstrip line _ fed aperture coupled stacked rectangular patch antenna in cylindrical coordinate system 本文从麦克斯韦旋度方程出发,建立了笛卡儿坐标下无源空间中均匀无耗媒质的fdtd基本方程和圆柱坐标下无源空间中均匀无耗媒质的fdtd基本方程,详细讨论了fdtd法计算中时间步长和空间步长的选取原则以及激励源的类型和设置;推导了mur一阶和二阶边界条件在圆柱坐标下的差分格式;给出了在用fdtd法计算天线的远场辐射特性时必需采用的频域和时域近场远场变换技术;最后用fdtd法计算了平面微带缝隙天线、柱面共形微带缝隙天线和柱面共形微带层叠天线的输入阻抗和远区辐射场,并分析了天线的一些参数的变化对天线输入阻抗的影响,得出了一些有用的结论。
far: adj. (farther , further; far ...zone: n. 1.【地理】(地)带。 2.区域,范围,界。 3. ...far zone condition: 远区条件far zone field: 远区电磁场as far as: 就而言; 就…而言;至于; 像…那样远,远到,直到,至于; 远达; 远到, 直到, 至于; 远至,到……程度; 直到by far: (后接形容词最高级)得多,最; 大大地; 得多(修饰比较级或最高级); 得多,最最; 得多最; 非常,最(修饰比较级和最高级); 很多,最; 迄今; 远,非常(与比较级或最高级连用); 至今为止; 最,……得多; 最,……得多far: adj. (farther , further; farthest , furthest ) 1.远隔的;离得远的,上远路的,长途的。 2.较远的,远处的。 3.久远的,上了年纪的。 a far country 遥远的国家。 a far traveller 远行者。 the far side of the room 屋子的那一边。 the far side of a horse 马的右边,下马的那边[上马由左边]。 a statesman of far sight 目光远大的政治家。 the far past 太古时候,很久以前。 the Far West (尤指美国)西部地方。 adv. 〔比较形同上〕 1.〔地点〕远,远隔,远在。 ★口语中表示地点时。 far 主要用于疑问句和否定句,肯定句中的表现方式是: We went a long way 〔书面语… went far〕。 The house is a long way off 〔书面语… is far〕。 2.(时间)遥远,久远。 3.(程度)很,极,大,…得多, far ahead 远在前面。far away [off] 远隔,在老远处。 the far distant past 久远以前, far back in the past 远古,在很久以前。 as far back as the 18th century 远在十八世纪。 go so far as to 竟然到…的地步,甚至…。 far into the night 到深夜。 far better 好得很。 I cannot say how far his story is true. 我不能说他的话可靠到什么程度。 a far cry 距离很远;大不相同 (It is a far cry to London. 到伦敦很远。 It is a far cry from a magic lantern to television. 电视与幻灯大不相同)。 as far as 1. 远到,直到 (go as far as Africa 远至非洲)。 2. 就;尽;至于(as far as possible 尽可能,尽量)。 as far as in me lies 尽我的力量。 as [so] far as it goes 就现状来说,就其本身而言。 as far as I know 就我所知 (= so far as I know)。 by far (修饰比较级,最高级,表示数量,程度等)…得多;尤其;更(This is by far the best. 这个尤其好)。 far and apart 远离着,远隔着。 far and away 非常;大大,…得多,肯定的,无疑地 (He is far and away the greatest poet living. 他是目前最最伟大的诗人)。 far and near [nigh] 远近,到处,四面八方。 far and wide 遍,广泛地,到处。 far be it from me 我决不会。 (few and) far between 极少,偶尔。 far from 1. 远离。 2. 决不,决没有,完全不 (far from Paris 远离巴黎的地方。 It's far from perfect. 那还远远算不上完善)。 far from it! 差得远呢! (be) far gone (病等)更加厉害;大醉;(欠债)更多。 far out 〔美俚〕 1. 不寻常的。 2. (政见等)极端的。 3. 奥秘的,秘传的。 from far 从远处。 from far and near 从各处;远近都…。 go far 1. 成功,成名。 2. 长时间保持,大有帮助。 go far towards 大有助于,大有贡献于。 go far with 很能感动…,对…有巨大力量[影响]。 how far 1. (离…)多远 (How far is it to the office 离办公室多远?)。 2. 到什么程度[范围] (I don't know how far to trust them. 我不知道应该相信他们到什么程度)。 in so far as (表示程度、范围)就…,尽…,至于。 so [thus] far 到目前(此地)为止;就此范围[程度]来说。 So far , so good. 到现在为止,一直都还不错。 so far as 尽…说,就…说;只就…说 (So far as I know. 就我知道的说)。 so far as ... concerns 就…说。 n. -ness far as: 那么远; 远至到in as far as: 在...的限度内, 在...的范围内, 到如此程度in the far: 在那遥远的地方is it far: 很远吗that far: 到那里为止,那么远as far as as far as: 大概来说by far by far: 翻了两番t zone: 移行区the zone: 危险地带zone: n. 1.【地理】(地)带。 2.区域,范围,界。 3.〔古、诗〕(腰)带。 4.圈,环带。 5.【数学】(球面)带;【物理学】晶带;晶层。 6.〔美国〕(为计算邮包寄费而划分的)邮包区 (= parcel post zone)。 7.【自动化】(穿孔卡片顶部的)三行区。 the frigid [temperate, torrid] zone 寒[温、热]带。 a fortified zone 要塞地带。 the zone of action 作战区域。 a school [business, residence] zone 学校[商业、住宅]区。 the zone of influence 势力范围。 soil zone 土层。 in the zone 〔俚语〕处于颠峰状态。 loose the maiden zone of 破坏…的处女童贞。 zone out (使)变得昏头昏脑,(使)变得昏昏沉沉。 vt. 1.用带圈绕。 2.把…分成地带。 as far as is known as far as: …那么远far and near; far and wide: 远远近近far arm and far instep: 跪撑中抓握远侧臂腿翻far far place: 很远很远的地方; 郁讵far knee and far instep: 侧握大小腿翻far, far away: 多说无益,就让眼泪和雨水来证明from a far from a far: 从遥远的地方so far as…, as far as…: 就…说,在…范围内,到…程度; 那么远,远到,直到
far zoneとは意味:遠距離帯{えんきょり たい} far zone meaning:[Electronics] See FAR FIELD, 1, 2. fast access storage In a computer memory, the section from which information can be most quickly accessed, depending on the relative speed of other system devices. far zone artinya:mintakat jauhfar zone перевод:зона излучения