Chapter 5 Conclusions Conclusions
A.2 The results of LHCP and RHCP modified lossless T-junction power divider 2 8
The real and imaginary parts of S-matrix when the radiating patches are excluded, and only the modified lossless T-junction power divider 2 8 networks both of LHCP (Figure 4.21) and RHCP (Figure 4.22) operated in CST software at f = 1.25 GHz are shown in equation (A2.1) and (A2.2), respectively.
(A2.1)
87
We define that [𝑆] and [𝑆]∗ are transpose and a conjugate matrix of (A2.1), respectively.
(A2.2)
88
Also, we notice that [𝑆] and [𝑆]∗ are consecutively transpose and a conjugate matrix of (A2.2). For reciprocity, they are clear for both LHCP and RHCP, i.e., [𝑆] = [𝑆] and [𝑆] = [𝑆] .
The matched ports of the divider set for LHCP S11 = 0.14 - 0.5i , S22 = -0.23 - 0.19i, S33 = -0.2 - 0.19i , S44 = -0.27 - 0.21i, S55 = -0.27 - 0.1i, S66 = -0.29 - 0.11i, S77 = -0.27 - 0.23i , S88 = -0.21 - 0.22i, S99 = -0.22 - 0.19i, S1010 = -0.22 - 0.21i, S1111 = -0.21 - 0.2i , S1212 = -0.22 - 0.23i, S1313
= -0.29 - 0.09i, S1414 = -0.28 - 0.1i, S1515 = -0.27 - 0.21i, S1616 = -0.21 - 0.2i, and S1717 = -0.23 - 0.19i, and for RHCP S11 = 0.14 - 0.5i, S22 = -0.27 - 0.21i, S33 = -0.28 - 0.1i, S44 = -0.23 - 0.19i, S55 = -0.21 - 0.2i, S66 = -0.21 - 0.2i, S77 = -0.22 - 0.2i, S88 = -0.29 - 0.09i, S99 = -0.22 - 0.23i, S1010 = -0.27 - 0.23i, S1111 = -0.29 - 0.11i, S1212 = -0.22 - 0.19i, S1313 = -0.21 - 0.22i, S1414 = -0.2 - 0.19i, S1515 = -0.23 - 0.19i, S1616 = -0.27 - 0.1i, and S1717 = -0.27 - 0.21i are relatively close to zero. It means that only a little bit of the incident waves on the matched port will be reflected or not exit the ports. Thus, the reflected waves at the ports will close to zero. We get that both LHCP and RHCP are almost the lossless of the power divider, [𝑆] [𝑆]∗= [𝐼] 𝑜𝑟 [𝑆∗] [𝑆] = [𝐼], as seen in equation (A2.3) and (A2.4).
89
(A2.3)
90
91
(A2.4)
92
93
Appendix B
List of terminology
In this part, we describe some terminologies that is used in this dissertation.
Antenna efficiency: the ratio of the aperture effective area, Ae to its actual physical area, A. It describes the percentage of the physical aperture area which captures Radio Frequency (RF) energy.
Antenna feed: the components of an antenna which feed the radio waves to the rest of the antenna structure, or in receiving antennas collect the incoming radio waves, convert them to electric currents and transmit them to the receiver.
Axial ratio: electromagnetic radiation with elliptical, or circular, polarization. The axial ratio is the ratio of the magnitudes of the major and minor axis defined by the electric field vector.
Bandwidth: the bandwidth of an antenna refers to the range of frequencies over which the antenna can operate correctly. The antenna's bandwidth is the number of Hz for which the antenna will exhibit a Standing Wave Ratio (SWR) less than 2:1.
Beamwidth: the half power beam width that is the angle between the half-power (-3 dB) points of the main lobe, when referenced to the peak effective radiated power of the main lobe. Beamwidth is usually but not always expressed in degrees and for the horizontal plane.
Circular polarization: a polarization state in which, at each point, the electric field of the wave has a constant magnitude, but its direction rotates with time at a steady rate in a plane perpendicular to the direction of the wave.
dB: a logarithm to measure of relative power. Antenna gain is measured in decibels as either dBi or dBd. dBi refers to dB away from a theoretical isotropic antenna, while dBd relates to dB away from a more real-world reference dipole antenna with a gain of 2.15 dB.
94
dBi: to define the gain of an antenna system relative to an isotropic radiator at radio frequencies.
The symbol is an abbreviation for "decibels relative to isotropic."
dBic: similar with dBi that gain of an antenna based on the isotropic antenna which has characteristic of propagation wave formed circularly.
Gain: a key performance number which combines the antenna's directivity and electrical efficiency. In a transmitting antenna, the gain describes how well the antenna converts input power into radio waves headed in a specified direction.
Impedance: as an electromagnetic wave travels through the different parts of the antenna system (radio, feed line, antenna, free space) that may encounter differences in impedance (E/H, V/I, etc.). At each interface, depending on the impedance match, some fraction of the wave's energy will reflect the source, forming a standing wave in the feed line.
Input impedance: the measure of the opposition to current flow (impedance), both static (resistance) and dynamic (reactance), into the load network being that is external to the electrical source.
Linear polarization: confinement of the electric field vector or magnetic field vector to a given plane along the direction of propagation.
Low Earth Orbit: an orbit around Earth with an altitude of 2,000 km (1,200 mi) or less, and with an orbital period of between about 84 and 127 minutes.
Matching impedance: the practice of designing the input impedance of an electrical load or the output impedance of its corresponding signal source to maximize the power transfer or minimize signal reflection from the load.
Microstrip antenna: an antenna fabricated using microstrip techniques on a Printed Circuit Board (PCB).
95
Null: an area or vector in an antenna's radiation pattern where the signal cancels out almost entirely.
Polarization: the direction in which the electrical field of an electromagnetic wave points.
Q-factor: a figure-of-merit that is representative of the antenna losses. Typically, there are radiation, conduction (ohmic), dielectric and surface wave losses.
Radiation efficiency: the power radiated over the input power. It can also be expressed regarding the quality factors, which for a microstrip antenna can be written as:
rad t t
rad
cdsw Q
Q Q
e Q
/ 1
/
1 (B.1)
where Qt is given by
sw d c rad
t Q Q Q Q
Q
1 1 1 1
1 (B.2)
where
Qt = total quality factor
Qrad = quality factor due to radiation (space wave) losses Qc = quality factor due to conduction (ohmic) losses Qd = quality factor due to dielectric losses
Qsw = quality factor due to surface waves
Radiation pattern: in the field of antenna design the term radiation pattern (or antenna pattern or far-field pattern) refers to the directional (angular) dependence of the strength of the radio waves from the antenna or other sources.
Reflection coefficient: the measure of the opposition to current flow (impedance), both static (resistance) and dynamic (reactance), into the load network being that is external to the electrical source.
S-matrix: the electrical behavior of linear electrical networks when undergoing various steady state stimuli by electrical signals.
96
S-parameter: members of a family of similar parameters, other examples being: Y-parameters, Z-parameters, H-Z-parameters, T-parameters or ABCD-parameters. They differ from these, in the sense that S-parameters do not use open or short circuit conditions to characterize a linear electrical network; instead, matched loads are applied. These terminations are much easier to use at high signal frequencies than open-circuit and short-circuit terminations. Moreover, the quantities are measured regarding power.
Parameters of antenna: gain, radiation pattern, beamwidth, polarization, and impedance. The antenna pattern is the response of the antenna to a plane wave incident from a given direction or the relative power density of the wave transmitted by the antenna in a given direction.
97
List of publications
Reference theses
[1] Muhammad Fauzan Edy Purnomo and Akio Kitagawa, Analysis Performance of Triangle Microstrip Antenna for Basic Construction of Circularly Polarized-Synthetic Aperture Radar Application, Jurnal Teknologi, Vol. 80, No. 2, pp. 93-104, March 2018.
[2] Muhammad Fauzan Edy Purnomo and Akio Kitagawa, Development of Sixteen Elements of Microstrip Triangular Array Antenna for Circularly Polarized-Synthetic Aperture Radar Sensor Application, Journal of Fundamental and Applied Sciences, Vol. 10, No. 5S, pp. 535-550, March 2018.
[3] Muhammad Fauzan Edy Purnomo, Akio Kitagawa, Triangular Microstrip Antenna for Circularly-Polarized Synthetic Aperture Radar Sensor Application, Indonesian Journal of Electrical Engineering and Computer Science, Vol. 12, No. 1, October 2018.
Sub-theses
[1] Muhammad Fauzan Edy Purnomo, Sholeh Hadi Pramono, Mauludi Ariesto Pamungkas, and Taufik, Study of The Effect of Air-Gap on Array Microstrip Antenna Performances for Mobile Satellite Communications, ARPN Journal of Engineering and Applied Sciences, Vol.
10, No. 20, November 2015.
[2] Muhammad Fauzan Edy Purnomo, Hadi Suyono, Panca Mudjirahardjo, and Rini Nur Hasanah, Analysis Performance of Singly-Fed Circularly Polarized Microstrip Antenna for Wireless Communication, Jurnal Teknologi, Vol. 78, No. 5-9, May 2016.
[3] Muhammad Fauzan Edy Purnomo, Onny Setyawati, Hadi Suyono, Rini Nur Hasanah, Panca Mudjirahardjo, and Rahmadwati Rahmadwati, The Analysis of Stub on Coplanar-Fed of Single and Array Microstrip Antenna for Mobile Satellite Communication, International Journal on Advanced Science, Engineering and Information Technology, Vol. 7, No. 5, pp.
1927-1933, October 2017.
[4] Muhammad Fauzan Edy Purnomo and Akio Kitagawa, Developing Basic Configuration of Triangle Array Antenna for Circularly Polarized-Synthetic Aperture Radar Sensor Application, Proceedings of IEEE: International Conference on Radar, Antenna, Microwave, Electronics, and Telecommunications (ICRAMET 2017), pp. 112-117, October 2017.
98
[5] Muhammad Fauzan Edy Purnomo and Akio Kitagawa, Development of Sixteen Elements of Microstrip Triangular Array Antenna for Circularly Polarized-Synthetic Aperture Radar Sensor Application, Proceedings of International Conference on Electrical Engineering and Computing (ICEEComp2018), Session 3A, Paper ID 92, March 2018.
[6] Muhammad Fauzan Edy Purnomo and Akio Kitagawa, Development of Equilateral Triangular Array Antenna with Truncated-Tip for Circularly Polarized-Synthetic Aperture Radar Sensor Application, Proceedings of 12th European Conference on Synthetic Aperture Radar, Session E.10, June 2018.
[7] Muhammad Fauzan Edy Purnomo and Akio Kitagawa, Triangular Microstrip Antenna for Circularly-Polarized Synthetic Aperture Radar Sensor Application, 12th International Power Engineering, Optimization and Computing Conference (PEOCO2018), Paper ID: 59, July 2018.
99
Acknowledgements
I would like to express my sincere gratitude to Professor Akio Kitagawa for his support and guidance during my study. I can increase my knowledge of him.
I would like to express my gratitude to the Microelectronic Research Laboratory (MeRL), Electrical Engineering and Computer Science, Graduate School of Natural Science and Technology, Kanazawa University, Japan for the support of facilities to this research published in the journal, conference, and dissertation.
Also, I would like to thank the Laboratory of Antenna, Chiba University, Japan for the partial data of the modeling and measurement used in this dissertation.
I would like to thank Ministry of Finance, Indonesia Endowment Fund for Education (LPDP) and the Directorate General of Resources for Research, Technology and Higher Education (RISTEKDIKTI), Ministry of Research, Technology and Higher Education of the Republic of Indonesia for financial support. And also for Brawijaya University, especially the Department of Electrical Engineering, Faculty of Engineering, for the help in my study.
I say thanks to all my lab mate for their support and useful discussions in my work. My thanks also for all my friends for all the help.
Finally, I would like to thank my beloved wife and family. Their endless support and praying give big encouragement to me.
100
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