濾波器是微波、射頻和通信系統中常用的器件之一,其功能是在系統中把有用的頻率信號分離出來,而把無用的頻率信號給濾除掉。按濾波器的幅頻響應或衰減特性,微波濾波器可以分為低通濾波器、高通濾波器、帶通濾波器和帶阻濾波器四種類型;按濾波器的結構,常用的微波濾波器可以分為集總LC濾波器、傳輸線結構濾波器、腔體濾波器、波導濾波器、交叉耦合濾波器等多種類型。在現代微波濾波器設計方法中,無論上述何種類型的微波濾波器,都可以由低通原型濾波器設計變換而來。
那(nei)么,該門(men)課程就(jiu)來向大(da)家全面、系統地介紹現代微(wei)波(bo)(bo)(bo)(bo)(bo)濾(lv)(lv)(lv)波(bo)(bo)(bo)(bo)(bo)器(qi)設計(ji)所涉及到(dao)的(de)基本的(de)理論知(zhi)識、設計(ji)方法和(he)設計(ji)流程,包括:濾(lv)(lv)(lv)波(bo)(bo)(bo)(bo)(bo)器(qi)的(de)技術參(can)數(shu),低(di)通(tong)原(yuan)型濾(lv)(lv)(lv)波(bo)(bo)(bo)(bo)(bo)器(qi)的(de)分(fen)析設計(ji),把低(di)通(tong)、高(gao)通(tong)、帶(dai)通(tong)、帶(dai)阻(zu)濾(lv)(lv)(lv)波(bo)(bo)(bo)(bo)(bo)器(qi)映(ying)射(she)到(dao)低(di)通(tong)原(yuan)型濾(lv)(lv)(lv)波(bo)(bo)(bo)(bo)(bo)器(qi)的(de)頻率變換,把集總(zong)LC元件(jian)濾(lv)(lv)(lv)波(bo)(bo)(bo)(bo)(bo)器(qi)變換成(cheng)分(fen)布式參(can)數(shu)元件(jian)(微(wei)帶(dai)傳輸線、微(wei)波(bo)(bo)(bo)(bo)(bo)腔體、波(bo)(bo)(bo)(bo)(bo)導(dao)、同軸線)結構(gou)微(wei)波(bo)(bo)(bo)(bo)(bo)濾(lv)(lv)(lv)波(bo)(bo)(bo)(bo)(bo)器(qi)的(de)變化方法(如K,J變換器(qi)、Rachards變換和(he)Kuroda規則(ze))。通(tong)過(guo)課程的(de)學習,為大(da)家設計(ji)實際的(de)微(wei)帶(dai)傳輸線結構(gou)、腔體結構(gou)和(he)波(bo)(bo)(bo)(bo)(bo)導(dao)結構(gou)的(de)微(wei)波(bo)(bo)(bo)(bo)(bo)濾(lv)(lv)(lv)波(bo)(bo)(bo)(bo)(bo)器(qi)打(da)下堅(jian)實的(de)基礎。
高低阻抗線微帶濾波器(又名階梯阻抗或階躍阻抗濾波器,英文名為Stepped Impedence Filter),是一種常用的低通微波濾波器,其結構簡單,易于加工,應用廣泛。
該部分就是專門來講解高低阻抗線微帶濾波器的設計,以及如何使用CST軟件來仿真分析高低阻抗線微帶濾波器的性能。課程從以微波濾波器綜合設計為基礎的原型電路設計法出發,全面透徹地講解了高低阻抗線微波濾波器的工作原理和設計計算;并通過具體的設計實例,詳細介紹了高低阻抗線微帶濾波器的實際設計步驟,同時演示和講解了使用CST微波工作室仿真分析高低阻抗線微帶濾波器的全過程。
通過課程的學習,可以幫助學員快速、全面、透徹地理解高低阻抗線微帶濾波器的設計原理,學會并掌握高低阻抗線微帶濾波器的設計流程和CST仿真分析操作。
1. 課程內容介紹
2. 微波濾波器的主要技術參數
詳細介紹表(biao)征微波濾波器性能的主要技術參數(shu),及其具體定(ding)義
3. 低通原型濾波器
集總元件(jian)低(di)通(tong)(tong)(tong)原(yuan)(yuan)型(xing)濾(lv)(lv)波(bo)器(qi)(qi)(qi)(qi)是(shi)現代網絡綜(zong)合法設(she)計微波(bo)濾(lv)(lv)波(bo)器(qi)(qi)(qi)(qi)的(de)基礎,各種(zhong)類(lei)(lei)型(xing)和各種(zhong)結(jie)構(gou)的(de)微波(bo)濾(lv)(lv)波(bo)器(qi)(qi)(qi)(qi)都是(shi)根據低(di)通(tong)(tong)(tong)原(yuan)(yuan)型(xing)濾(lv)(lv)波(bo)器(qi)(qi)(qi)(qi)變換而來(lai)。本講就(jiu)來(lai)詳細講解什么(me)是(shi)低(di)通(tong)(tong)(tong)原(yuan)(yuan)型(xing)濾(lv)(lv)波(bo)器(qi)(qi)(qi)(qi)以(yi)及(ji)如何得到低(di)通(tong)(tong)(tong)原(yuan)(yuan)型(xing)濾(lv)(lv)波(bo)器(qi)(qi)(qi)(qi),內容包括低(di)通(tong)(tong)(tong)原(yuan)(yuan)型(xing)濾(lv)(lv)波(bo)器(qi)(qi)(qi)(qi)的(de)定義(yi)、結(jie)構(gou)和綜(zong)合設(she)計方法,以(yi)及(ji)三種(zhong)常用的(de)類(lei)(lei)型(xing)低(di)通(tong)(tong)(tong)濾(lv)(lv)波(bo)器(qi)(qi)(qi)(qi)——巴(ba)特沃斯(si)、切比雪夫和橢圓函(han)數低(di)通(tong)(tong)(tong)原(yuan)(yuan)型(xing)濾(lv)(lv)波(bo)器(qi)(qi)(qi)(qi)的(de)分(fen)析設(she)計。
4. 頻率變換
低(di)(di)通(tong)(tong)(tong)、高通(tong)(tong)(tong)、帶(dai)通(tong)(tong)(tong)和帶(dai)阻(zu)濾(lv)(lv)(lv)波(bo)器(qi)(qi)在設(she)計(ji)時(shi),第一(yi)(yi)步是(shi)要找到(dao)滿足其設(she)計(ji)指標(biao)的(de)低(di)(di)通(tong)(tong)(tong)原(yuan)(yuan)(yuan)型(xing)(xing)濾(lv)(lv)(lv)波(bo)器(qi)(qi)。這(zhe)(zhe)一(yi)(yi)講(jiang)主(zhu)要講(jiang)解低(di)(di)通(tong)(tong)(tong)、高通(tong)(tong)(tong)、帶(dai)通(tong)(tong)(tong)、帶(dai)阻(zu)濾(lv)(lv)(lv)波(bo)器(qi)(qi)與低(di)(di)通(tong)(tong)(tong)原(yuan)(yuan)(yuan)型(xing)(xing)濾(lv)(lv)(lv)波(bo)器(qi)(qi)在頻(pin)率(lv)域的(de)映(ying)射關系,即頻(pin)率(lv)變(bian)換(huan);通(tong)(tong)(tong)過頻(pin)率(lv)變(bian)換(huan)可以設(she)計(ji)出與低(di)(di)通(tong)(tong)(tong)、高通(tong)(tong)(tong)、帶(dai)通(tong)(tong)(tong)或帶(dai)阻(zu)濾(lv)(lv)(lv)波(bo)器(qi)(qi)相對應的(de)低(di)(di)通(tong)(tong)(tong)原(yuan)(yuan)(yuan)型(xing)(xing)濾(lv)(lv)(lv)波(bo)器(qi)(qi)。得到(dao)了滿足設(she)計(ji)指標(biao)的(de)低(di)(di)通(tong)(tong)(tong)原(yuan)(yuan)(yuan)型(xing)(xing)濾(lv)(lv)(lv)波(bo)器(qi)(qi)后,還需要對低(di)(di)通(tong)(tong)(tong)原(yuan)(yuan)(yuan)型(xing)(xing)濾(lv)(lv)(lv)波(bo)器(qi)(qi)電路元件(jian)進行(xing)反歸一(yi)(yi)化(hua)處理,以得到(dao)實際的(de)集總L、C濾(lv)(lv)(lv)波(bo)器(qi)(qi)電路;這(zhe)(zhe)一(yi)(yi)講(jiang)也詳細講(jiang)解了從低(di)(di)通(tong)(tong)(tong)原(yuan)(yuan)(yuan)型(xing)(xing)濾(lv)(lv)(lv)波(bo)器(qi)(qi)變(bian)換(huan)到(dao)實際L、C濾(lv)(lv)(lv)波(bo)器(qi)(qi)的(de)反歸一(yi)(yi)化(hua)過程。
5. 倒置變換器(K, J變換器)和耦合系數
在微(wei)波(bo)(bo)頻段,濾(lv)(lv)波(bo)(bo)器(qi)(qi)(qi)(qi)實(shi)(shi)際(ji)上多是使用(yong)(yong)像傳輸(shu)線(xian)、腔體和(he)波(bo)(bo)導等(deng)結(jie)(jie)構的(de)(de)分布式(shi)(shi)(shi)參(can)(can)數(shu)(shu)元(yuan)件(jian)來實(shi)(shi)現(xian),而很(hen)少使用(yong)(yong)集(ji)總LC元(yuan)件(jian)電路。設(she)計(ji)中有(you)多種(zhong)方法可以(yi)實(shi)(shi)現(xian)用(yong)(yong)分布式(shi)(shi)(shi)參(can)(can)數(shu)(shu)元(yuan)件(jian)結(jie)(jie)構來替換集(ji)總LC濾(lv)(lv)波(bo)(bo)器(qi)(qi)(qi)(qi)電路;其中倒(dao)置(zhi)變換器(qi)(qi)(qi)(qi)(即K、J變化器(qi)(qi)(qi)(qi))就是實(shi)(shi)現(xian)分布式(shi)(shi)(shi)參(can)(can)數(shu)(shu)元(yuan)件(jian)結(jie)(jie)構微(wei)波(bo)(bo)濾(lv)(lv)波(bo)(bo)器(qi)(qi)(qi)(qi)的(de)(de)一種(zhong)常用(yong)(yong)的(de)(de)設(she)計(ji)方法,外部(bu)Q和(he)耦合系數(shu)(shu)則是諧振結(jie)(jie)構帶通濾(lv)(lv)波(bo)(bo)器(qi)(qi)(qi)(qi)的(de)(de)常用(yong)(yong)設(she)計(ji)方法。這一講重點講解(jie)(jie)這兩(liang)種(zhong)方法的(de)(de)設(she)計(ji)思路和(he)設(she)計(ji)公式(shi)(shi)(shi),并通過一個微(wei)帶線(xian)結(jie)(jie)構微(wei)波(bo)(bo)濾(lv)(lv)波(bo)(bo)器(qi)(qi)(qi)(qi)的(de)(de)設(she)計(ji)實(shi)(shi)例,實(shi)(shi)際(ji)講解(jie)(jie)了倒(dao)置(zhi)變換器(qi)(qi)(qi)(qi)的(de)(de)具體設(she)計(ji)應用(yong)(yong)。
6. Richards變換和Kuroda規則
Richards變(bian)換和Kuroda規(gui)則(ze)是實(shi)現傳輸線結(jie)(jie)構微波濾波器(qi)的(de)(de)一(yi)(yi)種(zhong)常(chang)用的(de)(de)設(she)(she)(she)計(ji)(ji)方法(fa),這一(yi)(yi)講主(zhu)要講解(jie)Richards變(bian)換和Kuroda規(gui)則(ze)這一(yi)(yi)設(she)(she)(she)計(ji)(ji)方法(fa)的(de)(de)設(she)(she)(she)計(ji)(ji)思路和設(she)(she)(she)計(ji)(ji)應用,并通(tong)過一(yi)(yi)個微帶線結(jie)(jie)構微波濾波器(qi)的(de)(de)設(she)(she)(she)計(ji)(ji)實(shi)例,實(shi)際講解(jie)了(le)這一(yi)(yi)設(she)(she)(she)計(ji)(ji)方法(fa)的(de)(de)具體過程。
7. 微波濾波器的設計流程和仿真工具
這一講主要介紹微(wei)波(bo)濾波(bo)器設(she)計的(de)具體設(she)計流程和微(wei)波(bo)濾波(bo)器設(she)計時常用的(de)仿真分析工(gong)具。
8 高低阻抗線微帶濾波器的設計原理和設計步驟
詳細、透徹地介紹高低阻抗線微帶濾波器的工作原理,從以低通原型濾波器為基礎的綜合設計法出發,推導給出高低阻抗線微帶濾波器的結構參數和低通原型濾波器電路元件值之間的等效關系,從而給出由低通原型濾波器來設計高低阻抗線微帶濾波器設計步驟和計算公式,包括高、低阻抗線特征阻抗的選取以及高、低阻抗線長度的計算。
9. 高低阻抗線微帶濾波器設計實例
通過一個高低阻抗線微帶低通濾波器的實際設計實例,并結合CST軟件中的微帶線計算工具,來講解高低阻抗線微帶濾波器具體的設計步驟以及高低阻抗微帶線結構尺寸實際計算。
10. 高低阻抗線微帶濾波器的CST仿真分析實作
實例演示和講解使用CST仿真分(fen)(fen)析高(gao)低(di)(di)阻抗(kang)(kang)線微帶(dai)濾波器的完(wan)整(zheng)過(guo)程,包括設(she)計(ji)建模、求解器選(xuan)擇(ze)、激(ji)勵(li)端口設(she)置、邊(bian)界條件(jian)設(she)計(ji),直(zhi)至終(zhong)給出分(fen)(fen)析結(jie)果(guo)。另外(wai),根(gen)據前(qian)面介紹的設(she)計(ji)原理,設(she)計(ji)出的高(gao)低(di)(di)阻抗(kang)(kang)線微帶(dai)低(di)(di)通濾波器通常會存在(zai)(zai)通帶(dai)截止(zhi)(zhi)頻率偏(pian)(pian)低(di)(di)的問(wen)題。在(zai)(zai)這部分(fen)(fen)內容(rong)的后,還會講解如(ru)何根(gen)據分(fen)(fen)析結(jie)果(guo)來調整(zheng)高(gao)低(di)(di)阻抗(kang)(kang)線濾波器的結(jie)構尺寸,以解決通帶(dai)截止(zhi)(zhi)頻率偏(pian)(pian)低(di)(di)的問(wen)題,從而達到(dao)實際的設(she)計(ji)要求。
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