Development of Circularly Polarized Microstrip ... - CEReS - åèå¤§å¦

More documents

Recommendations

Info

a 2 =0) and can be defined as S 11 = Z 1 − Z 0 Z 1 + Z 0 (3.1) Where Z 1 is input impedance at port 1 (Ω) and Z 0 is impedance characteristic (Ω). 3.2.2 Antenna efficiency The efficiency of an antenna relates the power delivered to the antenna and the power radiated or dissipated within the antenna. Radiation efficiency is defined as the ratio of the total power radiated by an antenna to the net power accepted by the antenna from the connected transmitter. A high efficiency antenna has most of the power present at the antenna’s input radiated away. A low efficiency antenna has most of the power absorbed as losses within the antenna, or reflected away due to impedance mismatch. For example, if a transmitter delivers 100 W into an antenna having an efficiency of 80%, then the antenna will radiate 80 W as radio waves and produce 20 W of heat. In order to radiate 100 W of power, one would need to use a transmitter capable of supplying 125 W to the antenna. 3.2.3 Antenna Gain The term antenna gain describes how much power is transmitted in the direction of peak radiation when connected to a power source (Balanis, 2005). Gain is not a quantity which can be defined in terms of a physical quantity such as the Watt or the Ohm, but it is a dimensionless ratio. The antenna gain signifies the ratio of radiated power in a given direction relative to that of an isotropic radiator which is radiating the total amount of electrical power received by the antenna. In terms of U the antenna gain G in a specified direction can be calculated G = U(θ, φ) P in /4π (3.2) where U(θ, φ) is radiation intensity (Watt/unit solid angle), and P in signifies the electrical power received by the antenna from the transmitter(Watt). However, in measurement, the antenna gain is obtained from indirect measurement. The measured gain is relative gain that 33
defines as the ratio of the power gain in a given direction to the power gain of a reference antenna in its reference direction. 3.2.4 Polarization Polarization is defined as the orientation of the electric field of an electromagnetic wave. Polarization is in general described by an ellipse. Two often used special cases of elliptical polarization are linear polarization and circular polarization. The polarization of an electromagnetic wave can be categorized by using axial ratio (AR) parameter. Axial ratio is the ratio of the major axis to the minor axis of the polarization ellipse which commonly stated in dB unit. Figure 3.4 shows the elliptical polarization which the elliptical curve is formed by the tip of the instantaneous electric field vector. Here, ε and τ are the ellipticity angle and the tilt angle of the Figure 3.4: Parameters in electromagnetic wave polarization. microwave signal, respectively. The range value of ε is from -45 o up to 45 o and τ angle is from 0 o up to 180 o . Based on Figure 3.4, the ellipticity as a function of AR is defined as ε = cot −1 (−R) (3.3) The polarization of a microwave signal is categorized based on their axial ratio value (R). 34
Page 1 and 2: Development of Circularly Polarized
Page 3 and 4: Abstract The discussion about devel
Page 5 and 6: Acknowledgements First and foremost
Page 7 and 8: CONTENTS 3 Circularly Polarized Mic
Page 9 and 10: List of Figures 1.1 Electric field
Page 11 and 12: LIST OF FIGURES 5.13 Photograph of
Page 13 and 14: List of Tables 2.1 Parameters of CP
Page 15 and 16: in linear polarization has some fla
Page 17 and 18: polarization (RHCP) and left-handed
Page 19 and 20: BIBLIOGRAPHY Bibliography [1] Birk
Page 21 and 22: Chapter 2 Circularly Polarized Synt
Page 23 and 24: generates all the necessary timing
Page 25 and 26: line platform flight trajectory is
Page 27 and 28: Figure 2.6: Range ambiguities: Port
Page 29 and 30: Substituting (2.12) and (2.13) into
Page 31 and 32: Figure 2.9: Basic principle of aper
Page 33 and 34: CP-SAR geometry, the slant range ,
Page 35 and 36: Figure 2.12: The required (a) θ EC
Page 37 and 38: 2.5.2 Design of CP-SAR system 2.5.2
Page 39 and 40: BIBLIOGRAPHY Figure 2.15: Design of
Page 41 and 42: BIBLIOGRAPHY [14] Steven Z., Unmann
Page 43 and 44: developments of novel microstrip an
Page 45: to feed or excite a microstrip patc
Page 49 and 50: 3.2.6 Radiation pattern In the fiel
Page 51 and 52: Figure 3.6: Rectangular patch arran
Page 53 and 54: diagonals axis. The area of the per
Page 55 and 56: By substitute eq. (3.7-3.9) to (3.1
Page 57 and 58: 3.4.1 Linear array Among the differ
Page 59 and 60: provide additional variables which
Page 61 and 62: The beam area or solid angle or Ω
Page 63 and 64: 2005). An array of even number of i
Page 65 and 66: BIBLIOGRAPHY m = 8 cos(mu) = 128z 8
Page 67 and 68: BIBLIOGRAPHY [21] Rahmani M., Tavak
Page 69 and 70: Figure 4.1: Design methodology. 56
Page 71 and 72: Figure 4.2: Flow chart of the anten
Page 73 and 74: Figure 4.3: Diagram of required ant
Page 75 and 76: easy if you have the right equipmen
Page 77 and 78: Chapter 5 Results and Discussion 5.
Page 79 and 80: Figure 5.2: Geometry design of prop
Page 81 and 82: terminals during the radiation proc
Page 83 and 84: 5.1.4 Radiation characteristic The
Page 85 and 86: Figure 5.11: Measured and simulated
Page 87 and 88: the physical length, L, and the eff
Page 89 and 90: Figure 5.13: Photograph of the fabr
Page 91 and 92: Figure 5.15: Simulated and measured
Page 93 and 94: In Figure 5.18, the antenna gain wi
Page 95 and 96: Figure 5.20: Array antenna characte
Page 97 and 98:
Figure 3 shows the design and photo
Page 99 and 100:
Figure 5.24: Simulated and measured
Page 101 and 102:
5.4 Broadband circularly polarized
Page 103 and 104:
Figure 5.29: Axial ratio (AR) plott
Page 105 and 106:
Figure 5.33: A 3D beam pattern of t
Page 107 and 108:
Figure 5.34: Dolph-Chebyshev array
Page 109 and 110:
measurement, respectively. Such deg
Page 111 and 112:
Figure 5.40: Relationship between a
Page 113 and 114:
Figure 5.42: Array antenna characte
Page 115 and 116:
BIBLIOGRAPHY single-feed circular m
Page 117 and 118:
antenna for CP-SAR sensor. In the c
Page 119 and 120:
List of Publications Peer-reviewed
Page 121 and 122:
Curriculum Vitae YOHANDRI He was bo
Page 123 and 124:
To perform an electromagnetic simul
Page 125 and 126:
are integrated into MGRID. PATTERN
Page 127 and 128:
properly. After a rectangle is draw
Page 129 and 130:
Figure B.5: Frequency sweep in simu
Page 131 and 132:
Figure B.8: Three-dimensional far-f
Page 133 and 134:
Figure C.1: (a) Seven Mini PCB Prot
Page 135 and 136:
Figure C.3: Etching tank and chemic
show all

Development of Circularly Polarized Microstrip ... - CEReS - åèå¤§å­¦

Create successful ePaper yourself

Delete template?

Save as template?

Development of Circularly Polarized Microstrip ... - CEReS - åèå¤§å¦