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협대혁 LTCC 듀플랙서 기반 이동통신용 쿼드플랙서 구현

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Abstract
In this thesis, a narrow band pass filter(BPF) with less than 3% bandwidth has been realized by using LTCC (low temperature co-fired ceramic) technology. A quad-plexer has been designed and manufactured by combining a diplexer with four LTCC BPFs operating in the cellular band of 0.8 GHz and the WCDMA band of 2.1 GHz.
The LTCC band pass filter has been designed by adopting an ENG model in a classical DNG constitution based on meta-structure theory. Since the bandwidth of the proposed band pass filter in this thesis is less than 3%, it has a very narrow band feature as compared with conventional LTCC band pass filters. Therefore, the filter has been designed through optimization based on the ENG model in order to maximize efficiency. Three types of dielectric substances are used in the LTCC filter manufacturing process. Of the three, the NH20M4 substance has been chosen. This substance has a relatively low dielectric constant of 21, and allowing the low insertion loss and low frequency deviation. The electrode material contains more than 80% of metal content in order to raise the Q value of the resonator. During the production process, it displays optimal characteristics when the electrode membrane is coated twice using the 7251S electrodes by Namics. Therefore, in the final manufacturing process of the LTCC filter, it has been manufactured utilizing NH20M4 dielectric powder and coating the 7251S electrodes twice.
For a duplexer structure, two LTCC band pass filters have been implemented with capacitive λ/4 resonators designed to get optimal Q value through various forms of research. Specifically, the LTCC filters have been developed with a LTCC material with a permittivity of 21 and loss of 0.001
The Q value of 338 for the resonator in the cellular and WCDMA band. The designed filters are 5th order SMD (surface mount device) modules with a size of 22×10×3 mm3. The manufactured duplexer operating in cellular band is composed of two LTCC filters, which they have passband of 0.824∼0.849 GHz and 0.869∼0.894 GHz in transmit and receive frequency band, by conjunction them with a microstrip line combiner. This duplexer shows 4.5 dB loss and over 45 dB isolation.
The Q value of the resonators in the WCDMA band LTCC duplexer is greater than 300 and the filters are 5th order with a size of 20×5×3 mm3. In addition, the duplexer operating in the WCDMA band is composed of two LTCC filters, which they have passband of 2.11∼2.17 GHz transmit and 1.92∼2.17 GHz receive frequencies. Using the same structure as the cellular band duplexer, this duplexer shows 2.5 dB loss and over 60 dB isolation.
In order to combine the two LTCC duplexers on a printed circuit board, a diplexer consisting of a LPF in the low frequency band and a broadband band pass filter in high frequency band is realized by using a microstrip technology.
By combining the diplexer with the two LTCC duplexers, a quad-plexer has been developed to displaying desired performance. In addition, the quad-plexer has been measured by utilizing a VNA (vector network analyzer) and has been assessed for use in mobile communications. The measurement results show loss of 5 dB and isolation greater than 53dB in the cellular band and 3dB and 60 dB in the WCDMA band respectively. In conclusion, the compact size and displayed performance make it suitable for mobile RRH (remote radio head) of femto-cell BTS (base transceiver station) applications.
Author(s)
서수덕
Issued Date
2017
Awarded Date
2017. 2
Type
Dissertation
URI
http://dcoll.jejunu.ac.kr/jsp/common/DcLoOrgPer.jsp?sItemId=000000008004
Department
대학원 통신공학과
Advisor
양두영
Table Of Contents
Abstract 1
Ⅰ. 서론 3
Ⅱ. 메타 구조 이론을 이용한 필터 연구 7
1. 메타 구조 기본 이론 7
2. 공진기 간의 유도성 결합을 이용한 통과대역 특성 8
3. 임피던스 정합을 위해 양 끝 단의 공진 회로의 수정 9
4. 격리도 개선을 위한 필터링 기법 추가 9
5. DNG 구조와 ENG 구조의 필터링 특성 비교 10
6. 송수신 사이 격리도 향상을 위한 노치 구조 20
Ⅲ. LTCC 대역통과 필터 설계 26
1. 공진기 이론 26
2. 공진기 구조 29
3. 대역통과 필터 설계 32
4. 격리도 향상을 위한 노치 구조 추가 설계 40
5. 듀플랙서 설계 49
1) 셀룰러 대역 듀플랙서 설계 49
2) WCDMA 대역 듀플랙서 설계 52
Ⅳ. 광대역 다이플랙서 설계 55
1. 광대역 다이플랙서 설계 55
1) 셀룰러 대역 설계 56
2) WCDMA band 설계 60
3) 광대역 다이플랙서 설계 64
Ⅴ. LTCC 제작 공정 68
1. 유전체 및 전극재료 68
2. LTCC 적층필터 제조공정 69
1) 원료 성형 공정 69
1-1) 분쇄 및 분산 70
1-2) 탈포 및 에이징 70
1-3) 그린시트 성형 71
2) 인쇄 및 적층 공정 71
2-1) 펀칭 72
2-2) 비아충진 72
2-3) 스크린 인쇄 72
2-4) 적층 72
2-5) 가압접착 73
2-6) 절단 73
2-7) 탈바인더 73
3) 소성 73
3. 저온 소성용 Ag계 전극 페이스트 설정 및 수축거동 분석 74
Ⅵ. LTCC 듀플랙서 및 다이플랙서, 쿼드플랙서 제작 79
1. 셀룰러 대역 LTCC 듀플랙서 제작 결과 80
1) 셀룰러 대역 LTCC 대역통과 필터 제작 결과 80
2) 셀룰러 대역 LTCC 듀플랙서 제작 결과 85
2. WCDMA 대역 LTCC 듀플랙서 제작 88
1) WCDMA 대역 LTCC 대역통과 필터 제작 결과 88
2) WCDMA 대역 LTCC 듀플랙서 제작 결과 91
3. 2중대역 결합 광대역 다이플랙서 제작 93
1) 다이플랙서 제작 및 시험 결과 93
2) 다이플랙서 설계 결과와 시험 결과 비교 분석 97
4. LTCC 듀플랙서와 광대역 다이플랙서를 결합한 쿼드플랙서 제작 99
1) 쿼드플랙서 제작 및 측정 결과 99
1-1) 셀룰러 대역 수신단 특성 100
1-2) 셀룰러 대역 송신단 특성 101
1-3) WCDMA 대역 수신단 특성 103
1-4) WCDMA 대역 송신단 특성 104
2) 설계 결과와 제작 결과 특성 비교 105
2-1) 셀룰러 대역 수신단 특성 105
2-2) 셀룰러 대역 송신단 특성 106
2-3) WCDMA 대역 수신단 특성 107
2-4) WCDMA 대역 송신단 특성 108
Ⅶ. 결론 110
References 113
Degree
Doctor
Publisher
제주대학교 일반대학원
Citation
서수덕. (2017). 협대혁 LTCC 듀플랙서 기반 이동통신용 쿼드플랙서 구현
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General Graduate School > Telecommunication Engineering
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