Table of Contents ... 1 

T

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Table of Contents ... 1 

Sommario ... 3 

Abstract ... 3 

Acronyms ... 4 

Acknowledgements ... 4 

Introduction ... 5 

1  The Hybrid Approach for the Analysis of Aperture Antenna Problems... 7 

2  Computation of the GSM for the Internal Waveguide Region of the Antenna ... 10 

2.1  Analysis of a waveguide step junction ... 10 

2.1.1

2.1.2

2.1.3

2.1.4

2.1.5

2.2  Analysis of complex microwave devices ... 26 

2.2.1

2.2.2

2.3  Numerical results ... 28 

3  Computation Of The GSM For The Radiating Aperture By MoM Technique ... 34 

3.1  Set of MoM equations ... 34 

3.2  Evaluation of the excitation matrix... 36 

3.3  Evaluation of the admittance matrix for the inner side of the aperture .... 37 

3.4  Evaluation of the admittance matrix for the outer side of the aperture opened on an infinite PEC ground plane ... 39 

3.4.1

3.5  Evaluation of the GSM of the aperture and coupling with the internal

problem ... 47 

3.6  Numerical results ... 50 

4  Analysis Of Aperture Antenna Arrays ... 59 

4.1  Computation of the GSM for the Outer Problem ... 59 

4.2  Numerical results ... 64 

4.2.1

4.2.2

4.2.3

4.2.4

4.2.5

5  Analysis of Large Finite Arrays With The Characteristic Basis Functions Method ... 89 

5.1  Formulation of the hybrid method ... 89 

5.2  Generation of the Characteristic Basis Functions ... 90 

5.3  Generation of the reduced matrix and excitation vector ... 94 

5.4  Efficient generation of MoM matrices using the Characteristic Function method ... 95 

5.5  Numerical results ... 97 

6  Analysis Of Large Finite Periodic Arrays with a Spectral Decomposition Approach ... 106 

6.1  The Spectral Decomposition approach ... 106 

6.2  Mode Matching/Finite Element approach for the array element ... 110 

6.3  Numerical Results ... 110 

Conclusions ... 113 

References ... 116 

List of Publications ... 119