Designs and Applications of Compact Circularly Polarized Crossed Dipole Antennas
- 주제(키워드) Antenna , circular polarization , crossed dipole
- 발행기관 아주대학교
- 지도교수 Professor IKMO PARK
- 발행년도 2016
- 학위수여년월 2016. 2
- 학위명 박사
- 학과 일반대학원 전자공학과
- 실제URI http://www.dcollection.net/handler/ajou/000000021398
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
In this dissertation, single-feed circularly polarized (CP) crossed dipoles are incorporated with alternative engineering approaches for profile miniaturization, multiband operation, radiation pattern control, and bandwidth enhancement. A compact crossed dipole is realized with the use of a meander line and an arrowhead-shaped end in each dipole arm. A pair of vacant-quarter printed rings is used in the feeding structure to achieve CP radiation and allow the antenna be matched to a single 50-Ω source directly. For multi-band applications, each dipole arm is divided into multi-branches with different lengths to obtain multiple resonances. These compact radiators can be equipped with different reflectors, including finite planar metallic surface, metallic cavity, and finite artificial magnetic conductor (AMC), to obtain the desired antenna radiation characteristics.
more목차
1. INTRODUCTION 1
1.1 Circularly polarized antennas . 1
1.2 Crossed dipole antennas 1
1.3 Single-feed circularly polarized crossed dipoles 5
1.4 Specific radiation characteristics 8
1.5 Artificial magnetic conductor surface . 8
1.6 Motivations and contributions of the dissertation . 10
1.7 Dissertation organization 11
2. SINGLE-FEED COMPACT CIRCULARLY POLARIZED CROSSED DIPOLE ANTENNAS 14
2.1 Process to reduce dipole length 14
2.2 Compact circularly polarized crossed dipole 17
2.3 Dual-band circularly polarized crossed dipole . 20
3. CIRCULARLY POLARIZED RADIATION IMPROVEMENT BY USING CAVITY-BACKED REFLECTORS 25
3.1 Single-band antenna 25
3.2 Dual-band antenna 30
3.3 Multi-band antenna . 37
4. PROFILE MINIATURIZATION AND BANDWIDTH ENHANCEMENT OF COMPACT CROSSED DIPOLES BASED ON AMC SURFACES 45
4.1 Discovering and utilizing additional resonances of single-band crossed dipole on a finite AMC surface . 45
4.1.1 Antenna geometry 46
4.1.2 Performance comparison of crossed dipole on different reflector 49
4.1.3 Radiation mechanisms . 52
4.1.4 Measurements 55
4.2 Tri-band crossed dipole on an AMC surface 59
4.2.1 Antenna geometry 60
4.2.2 Tri-band crossed dipole in different configurations . 62
4.2.3 Measurements 68
4.3 Dual-band crossed dipole on dual-band AMC surface . 70
4.3.1 Dual-band AMC 70
4.3.2 Antenna structure . 73
4.3.3 Performance comparison of dual-band crossed dipole in different configurations 73
4.3.4 Measurements 78
5. INVESTIGATION OF SURFACE WAVE RESONANCES ON AMC-BASED CROSSED DIPOLE ANTENNAS 80
5.1 Cavity model . 81
5.2 Surface wave resonances of crossed dipole on finite AMC surface with grounding pins 83
5.2.1 AMC structure 83
5.2.2 Prediction of surface wave resonances . 85
5.2.3 HFSS simulation verification . 86
5.2.4 CP radiations . 91
5.2.5 Broadband AMC-based crossed dipole antennas using surface wave resonances . 98
5.3 Surface wave resonances of crossed dipole on finite AMC surface without grounding pins . 102
5.3.1 AMC structure 102
5.3.2 Prediction of surface wave resonances . 104
5.3.3 HFSS simulation verification . 105
5.3.4 CP radiations . 107
5.3.5 Broadband AMC-based crossed dipole antennas using surface wave resonances . 110
5.4 Discussion 113
6. CONCLUSIONS AND FUTURE WORKS 116
6.1 Summary 116
6.2 Future works 117
REFERENCES 119
AUTHORS PUBLICATIONS 126
