유전체가 삽입된 원통형 공진기에서 Contour Graph 방법을 이용한 공진주파수 계산에 관한 연구 = (A) Computation of the Resonant Frequencies using Contour Graph Method in the Dielectric loaded Cylindrical Cavity Resonators
저자
발행사항
서울 : 建國大學校 大學院, 1999
학위논문사항
학위논문(박사)-- 建國大學校 大學院 : 電子工學科 2000. 2
발행연도
1999
작성언어
한국어
주제어
KDC
569.642 판사항(4)
DDC
621.381332 판사항(21)
발행국(도시)
서울
형태사항
xii, 124p. : 삽도 ; 26cm
일반주기명
참고문헌: p. 121-124
소장기관
This thesis describes an analysis method of the electromagnetic fields in the dielectric loaded cylindrical cavity resonators. The dielectric loaded cylindrical cavity resonator is a microwave device which has very excellent properties like low-loss obtained from reducing the loss at wall since the electromagnetic field stored within the dielectric, high Q factors which are considerably higher than that of the cavity resonators and high temperature-stable. And it is also suitable for the miniaturization due to it's small size compared with the cavity resonators operating in the same frequency range.
The most popular dielectric loaded cylindrical cavity resonators for the microwave devices are the concentric dielectric disk loaded cylindrical cavity resonators. Concentric dielectric disk loaded cylindrical cavity resonators have the shape of concentrically inserted smaller dielectric disk than cavity resonator. Since electromagnetic fields are concentrated on concentric dielectric disk, high Q factors can be obtained by reducing the loss at the side and top wall of the resonator.
To calculate the Q factors and the resonant frequency of a concentric dielectric disk loaded cylindrical cavity resonator accurately, precise electromagnetic fields representation of outer area of dielectric in the resonator should be proceeded. The most important point in representing the electromagnetic fields of concentric dielectric disk loaded cylindrical cavity resonators is how to express the variation of electromagnetic fields along axial and radial direction on the outer area of dielectric in the resonators.
The inside electromagnetic field variation of concentric dielectric disk loaded cylindrical cavity resonators can be represented by assuming that evanescent mode and travelling mode exist in outer area of dielectric. Because most of electromagnetic fields are concentrated on the dielectric of which the dielectric constant is very high, evanescent mode assumes that electromagnetic fields are evanescent rapidly at the outer area of dielectric. The evanescent mode used in DWM method usually is an approximated representation. The evanescent mode can be applied only when the dielectric constant of dielectric is higher than that of outer area of dielectric. Travelling mode assumes that electromagnetic fields have the shape of standing wave which consists of traveling wave and reflected wave by assuming that all fields of inner and outer area of dielectric in the resonators travel toward the wall and reflect at the wall.
Recently, most of researchers including K. A. Zaki calculated Q and resonant frequencies of concentric dielectric disk loaded cavity resonators using DWM method. In DWM method, the electromagnetic field variations of axial and radial direction at outer area of dielectric in the concentric dielectric disk loaded cylindrical cavity resonators were represented as evanescent mode. The calculated resonant frequencies using the electromagnetic field representation with the assumption of evanescent mode tend to have a good agreement with the measured result only when the dielectric constant of concentric dielectric disk is very high and the size of concentric dielectric disk is similar to the size of cavity resonator.
R. F. Harrington treated the analysis of concentric dielectric rod loaded resonators which has no gap between concentric dielectric rod and top wall of cavity resonators. In the concentric dielectric rod loaded resonators, the electromagnetic field variations of outer area of concentric dielectric rod are represented with the assumption of travelling mode and then characteristic equations are obtained. The Harrington's method is an well matched approximation method only when the radius of the dielectric is much smaller than that of cavity resonator.
In the dielectric loaded resonators, the reason why approximated electromagnetic field representations in the resonators, especially, outer area of dielectric are used is that the solution of the characteristic equations can not be obtained accurately. The process of solving the characteristic equations is very complicated and difficult because the characteristic equations obtained by appling boundary conditions to electromagnetic field representations have the form of transcendental equation.
To solve the characteristic equation, numerical methods should be used since the analytic approach is not applicable. The numerical method like Newton's iteration requires complicated algorithm and the iterative operation. The iterative operation needs a lot of time and trial and errors. Also, the numerical method requires the process of mode identification, but mode identification itself is very difficult. Since confirming whether electromagnetic field representations in the resonators is appropriate is very complicated, the analysis based on the approximated electromagnetic representation has been popular. This kinds of studies only concentrated on the calculation of resonant frequencies, and mode identification of resonant frequencies have not been covered. To understand characteristics of resonators, the mode of resonant frequencies is one of the key parameters.
Especially, for the computation of precise resonant frequencies of concentric dielectric disk loaded cylindrical cavity resonators, the variation of electromagnetic fields should be represented for the each area in the resonator which is divided into three parts. By appling boundary conditions for the radial and axial direction to the electromagnetic representation of each area, two characteristic equations having the form of transcendental equation can be obtained. Two variables in the two characteristic equations are resonant frequency and axial direction propagation constant of dielectric area. It is impossible to solve the transcendental equation with two variables with a analytic approach.
This thesis introduces contour graph method to solve allied two transcendental equation. Contour graph method uses graphical method. This method is not a method using approximated representations of electromagnetic field variations at the outer area of dielectric in the resonators but a method using exact representation to calculate resonant frequencies. Because the process to analyze the characteristic equations is simple and all parts of resonant frequency graph can be easily drawn, it is possible to calculate precise resonant frequencies and to identify the mode of resonant frequencies.
A contour graph method is essentially a "topographic map" of a function. The contours links the points on the surface that have the same value. Given the value of the contour, the goal is to find those values of x and y for which f(x , y) = z, where f is the function we are solving.
To use the contour graph method, basic mechanism to convert the characteristic equations into graphs. After converting each characteristic equation into two variables function, plot the contour graph of the points which make value of converted two variables functions zero. If the two contour graphs are overlapped, the crossing point of each contours for the two characteristic equations is appeared. As this crossing point is satisfy two characteristic equations simultaneously, it represent the resonant frequency and the propagation constant of axial direction of resonator. Each contours represent highest orders of radial direction and axial direction for the boundary conditions of radial direction and axial direction, respectively. Therefore, the crossing points of two contours represent resonant frequencies and modes.
The resonant frequencies of TMolo and TE011 mode of concentric dielectric rod loaded cylindrical cavity resonator is measured. Material of dielectric rod used in the experiment is teflon( Er= 2.06). Experimental measurements show excellent agreement with the numerical results. The difference between them of TMolo and TEou mode are 0.024[%]-0.247[%] and 0.057[%]-0.367[%] respectively.
The resonant frequencies of TE011+8 mode of concentric dielectric disk loaded cylindrical cavity resonator is measured. Material of concentric dielectric disk used in the experiment is sapphire( Er= 9.4). The calculated results well agree with the experimental ones. The error between them is 0.2[%] or I.6[%] for the case of the top plate is close to or far from the concentric dielectric disk, respectively.
분석정보
서지정보 내보내기(Export)
닫기소장기관 정보
닫기권호소장정보
닫기오류접수
닫기오류 접수 확인
닫기음성서비스 신청
닫기음성서비스 신청 확인
닫기이용약관
닫기학술연구정보서비스 이용약관 (2017년 1월 1일 ~ 현재 적용)
학술연구정보서비스(이하 RISS)는 정보주체의 자유와 권리 보호를 위해 「개인정보 보호법」 및 관계 법령이 정한 바를 준수하여, 적법하게 개인정보를 처리하고 안전하게 관리하고 있습니다. 이에 「개인정보 보호법」 제30조에 따라 정보주체에게 개인정보 처리에 관한 절차 및 기준을 안내하고, 이와 관련한 고충을 신속하고 원활하게 처리할 수 있도록 하기 위하여 다음과 같이 개인정보 처리방침을 수립·공개합니다.
주요 개인정보 처리 표시(라벨링)
목 차
3년
또는 회원탈퇴시까지5년
(「전자상거래 등에서의 소비자보호에 관한3년
(「전자상거래 등에서의 소비자보호에 관한2년
이상(개인정보보호위원회 : 개인정보의 안전성 확보조치 기준)개인정보파일의 명칭 | 운영근거 / 처리목적 | 개인정보파일에 기록되는 개인정보의 항목 | 보유기간 | |
---|---|---|---|---|
학술연구정보서비스 이용자 가입정보 파일 | 한국교육학술정보원법 | 필수 | ID, 비밀번호, 성명, 생년월일, 신분(직업구분), 이메일, 소속분야, 웹진메일 수신동의 여부 | 3년 또는 탈퇴시 |
선택 | 소속기관명, 소속도서관명, 학과/부서명, 학번/직원번호, 휴대전화, 주소 |
구분 | 담당자 | 연락처 |
---|---|---|
KERIS 개인정보 보호책임자 | 정보보호본부 김태우 | - 이메일 : lsy@keris.or.kr - 전화번호 : 053-714-0439 - 팩스번호 : 053-714-0195 |
KERIS 개인정보 보호담당자 | 개인정보보호부 이상엽 | |
RISS 개인정보 보호책임자 | 대학학술본부 장금연 | - 이메일 : giltizen@keris.or.kr - 전화번호 : 053-714-0149 - 팩스번호 : 053-714-0194 |
RISS 개인정보 보호담당자 | 학술진흥부 길원진 |
자동로그아웃 안내
닫기인증오류 안내
닫기귀하께서는 휴면계정 전환 후 1년동안 회원정보 수집 및 이용에 대한
재동의를 하지 않으신 관계로 개인정보가 삭제되었습니다.
(참조 : RISS 이용약관 및 개인정보처리방침)
신규회원으로 가입하여 이용 부탁 드리며, 추가 문의는 고객센터로 연락 바랍니다.
- 기존 아이디 재사용 불가
휴면계정 안내
RISS는 [표준개인정보 보호지침]에 따라 2년을 주기로 개인정보 수집·이용에 관하여 (재)동의를 받고 있으며, (재)동의를 하지 않을 경우, 휴면계정으로 전환됩니다.
(※ 휴면계정은 원문이용 및 복사/대출 서비스를 이용할 수 없습니다.)
휴면계정으로 전환된 후 1년간 회원정보 수집·이용에 대한 재동의를 하지 않을 경우, RISS에서 자동탈퇴 및 개인정보가 삭제처리 됩니다.
고객센터 1599-3122
ARS번호+1번(회원가입 및 정보수정)