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TITLE
DEDICATION
CERTIFICATE
DECLARATION
ACKNOWLEDGEMENT
1. INTRODUCTION
1.1 Introduction.
1.2 Types of Antennas.
1.2.1 Wire Antennas.
1.2.2 Aperture Antennas.
1.2.2.1. Reflector antennas
Fig. 1.2. Classification of reflector antenna systems
1.2.2.1. I. Plane Refleetor
I. 2.2.1.2. Corner Reflector.
1.2.2.1.3. Curved (conic) reflectors
Fig. 1.8. Parabolic cylindrical and Paraboloidal reflectors
1.2.3 Leaky wave Antennas.
1.2.4 Transmission Type Antennas.
1.2.5 Antenna Arrays..
figure 1.11. Transmission type antennas
1.2.6 Planar Antennas
1.3 Outline of the present work.
Fig. 1.13. Rectangular microstrip antenna
2. REVIEW OF THE PASTWORK IN THE FIELD
3. METHODOLOGY
3.1 Introduction.
3.2 Experimental facilities utilized.
3.2.1 8350 B-Sweep Oscillator.
Start/stop mode
CFIAF mode
CW mode
3.2.2 Hp 8743B Reflection Transmission test unit.
3.2.3 Hp 8411 A Harmonic frequency converter.
3.2.4 Hp 8410C / 8510B Network analyzer with display unit.
Fig. 3.1 Configuration of the basic measurement system.
Fig. 3.2. B l o c k dldqlam of the Network Analyzer system
3.2.5 Anechoic chamber.
3.2.6 Antenna Positioner and Controller.
Fig. 3.3 Schematic diagram of the convertible Anechoic chamber.
3.2.7 The X-Y Recorder.
3.3 Fabrication of the test Antenna.
Fig. 3.4. Diagrams of (a) Dipole (b) Corner reflector antenna.
Fig. 3. 5 (a) . The DCR antenna
Fig. 3.5 (b) The TCR antenna
3.4 The antenna holder and feeding facility.
3.5 The Experimental set up.
3.6 Method of measurements.
3.6.1 Radiation pattern.
Fig. 3.8. The experimental Setup
3.6.2 Directive gain.
3.6.3 Antenna Impedance and V S W R.
3.7 Motivation for the work.
4. EXPERIMENTAL RESULTS
4.1 Introduction.
4.2 The DCR Antenna.
Fig. 4.1 Schematic diagram of a DCR antenna
4.2.1 Effect of the various Antenna parameters on the gain.
4.2.2 Nature of dependence of Half Power Beam width on various Antenna parameters.
Table 4.1 (a)Relative gains of the various DCR antenna with respect to CR for a=120°
Table 4.1 (b)Relative gains of the various DCR antenna with respect to CR for a=90°
Table 4.2. (a) Variation of the HPBW for the various DCR antennas for a=120 O
Table 4.2 (b) Variation of HPBW for the various DCR antennas for a=90
4.2.3 Axial beam tilt for DCR Antennas.
4.2.4 Radiation patterns of the DCR Antennas.
Fig. 4.2. (a) Comparison of radiation patterns for DCR and CR antennas for a = 120
Fig. 4.2. (a) Comparison of radiation patterns for DCR and CR antennas for a = 120
Fig. 4.2. (a) Comparison of radiation pattems for DCR and CR antennas for a = 120
Fig. 4.2. (a) Comparison of radiation patterns for DCR and CR antennas for a = 120
Fig. 4.2 (a) Comparison of radiation pattenls for DCR and CR antennas for a = 1 20°
Fig. 4.2 (a) Comparison of radiation pattenis for DCR and CR antennas for a = 120°
Fig. 4.2 (b) Comparison of radiation patterns for DCR and CR antennas for a = 90
Fig. 4.2 (b) Comparison of radiation patterns for DCR and CR antennas for a = 90
Fig. 4.2 (b) Comparison of radiation patterns for DCR and CR antennas for a = 90
Fig. 4.3. Plot of VSWR and Impedance of DCR antennas against frequency
Fig. 4.3. Plot of VSWR and Impedance of DCR antennas against frequency
Fig. 4.3. Plot of VSWR and Impedance of DCR antennas against frequency
4.2.5 Sidelobe levels for the DCR Antennas.
4.2.6 Effect of width of the Strips on the radiation characteristics.
4.2.7 VSWR and Impedance.
4.2.8 Cross - Polar level.
4.3 The TCR Antenna.
Fig. 4.4. Schematic diagram of a TCR antenna
4.3.1 Effect of the various Antenna parameters on the gain of the TCR antenna.
Fig. 4.5. (a) Plot of the gain of TCR antenna versus passive comer angle
Fig. 4.5. (a) Plot of the gain of TCR antenna versus passive comer angle
Fig. 4.5. (a) Plot of the gain of TCR antenna versus passive comer angle
Fig. 4.5. (a) Plot of the gain of TCR antenna versus passive comer angle
Fig. 4.5 (b) Plot of the gain of TCR antenna versus passive comer angle
Fig. 4.5. (b) Plot of the gain of TCR antenna versus passive comer angle
Fig. 4.5. (b) Plot of the gain of TCR antenna versus passive comer angle
Fig. 4.5. (b) Plot of the gain of TCR antenna versus passive comer angle
4.3.2 Dependence of the HPBW on Antenna parameter.
4.3.3 Radiation patterns of the TCR Antennas.
Fig. 4.6 (a) Plot of HPBW of TCR antenna versus passive comer angle
Fig. 4.6. (a) Plot of MPBW of TCR antenna versus passive comer angle
Fig. 4.6. (a) Plot of HPBW of TCR antenna versus passive comer angle
Fig. 4.6. (a) Plot of HPBW of TCR antenna versus passive comer angle
Fig. 4.6 (b) Plot of HPBW of TCR antenna versus passive comer angle
Fig. 4.6. (b) Plot of HPBW of TCR antenna Versus passive comer angle
Fig. 4.6. (b) Plot of HPBW of TCR antenna versus passive comer angle
Fig. 4.6. (b) Plot of HPBW of TCR antenna versus passive comer angle
Fig. 4.7. (a) Comparison of radiation patterns of TCR and CR antennas for a = 90
Fig. 4.7. (a) Comparison of radiation patterns of TCR and CR antennas for a = 90
Fig. 4.7. (a) Comparison of radiation patterns of TCR and CR antennas for a = 90
Fig. 4.7. (a) Comparison of radiation patterns of TCR and CR antennas for a = 90
Fig. 4.7. (a) Comparison of radiation patterns of TCR and CR antennas for a = 90
Fig. 4.7. (a) Comparison of radiation patterns of TCR and CR antennas for a = 90
Fig. 4.7. (b) Comparison of radiation patterns of TCR and CR antennas for a = 120
Fig. 4.7. (b) Comparison of radiation patterns of TCR and CR antennas for a = 120
Fig. 4.7. (b) Comparison of radiation patterns of TCR and CR antemas for a = 120
Fig. 47. (b) Cornpa
Fig. 4.7. (b) Comparison of radiation patterns of TCR and CR antennas for a = 120
Fig. 4.7. (b) Comparison of radiation patterns of TCR and CR antennas for a = 1200
Fig. 4, 7. (b) Comparison of radiation patterns of TCR and CR antemas for a = lSoO
4.3.4 VSWR and Impedance.
Fig. 4.8. Plot of VSWR and Impedance of TCR antennas against frequency
Fig. 4.8. Plot of VSWR and Impedance of TCR antennas against frequency
Fig. 4.8. Plot of VSWR and Impedance of TCR antennas against frequency
4.3.5 The maximum sidelobe levels.
4.3.6 The Cross - Polar level.
4.4 The DCR Array system.
4.5 Conclusion.
Fig. 4.9 Schematic Diagram of a DCR array system
5. THEORETICAL CONSIDERATIONS
5.1 Introduction.
5.2 Analytical Method.
Fig. 5.1. Comer reflectors and their images for angles of 90°, 600, 450, 300
Fig. 5.2 Line source diffraction by wedgc
Fig. 5.3. Electric dipole parallel to a strip reflector
Fig. 5.4. Diagram of a 90
5.3 Field pattern of TCR Antenna.
Fig. 5.5 Image sources of a TCR
Fig. 5.6 Limits of illumination of I, and I,
Fig. 5 7 Limits of illumination of I2 and I4
Fig. 5.8 parameters for the computation of diffraction field of a TCR
Fig. 5.9 Comparison of theoretical and experimental radiation patterns of TCR antennas.
Fig. 5.10. Comparison of theoretical andexperimental radiation patterns of TCR antennas.
Fig. 5.1 1. Comparison of theoretical apd experimental radiation patterns of TCR antennas.
5.4 The DCR Antenna field pattern.
6. CONCLUSIONS
6.1 Introduction.
6.2 Inferences from the Experimental and Theoretical studies.
6.3 Scope for further work.
APPENDIX - I COMPLEX PERMITTIVITYMEASUREMENT OF LIQUIDS WITHCOAXIAL CAVITY RESONATORS USING APERTURBATION TECHNIQUE.
INTRODUCTION
DESIGN AND THEORETICAL CONSIDERATION
MEASUREMENT AND RESULTS
CONCLUSION
APPENDIX - 2AN ASYMMETRIC HOLLOWSECTORAI, DIELECTRIC HORNANTENNA AND ITS MODIFIEDRADUXTION CHARACTERISTICS
INTRODUCTION
ANTENNA DESIGN AND. EXPERIMENTAL SET-UP
EXPERIMENTAL RESULTS
CONCLUSION
REFERENCES
LIST OF PUSLICA TIONS OF JOE JACOB
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