La tentazione del racconto. Le novelle del primo Papini tra simbolismo e futurismo (1894-1914)

Sommaire

Scientific Publications v
List of Abbreviations vii
Introduction 1
1 Ferromagnetism in metallic nanowires 5
1.1 Magnetic materials . . . . . . . . . . . . . . . . . . . . . . 6
1.2 Microscopic scale for infinite medium . . . . . . . . . . . . 7
1.2.1 Equation of motion with static field . . . . . . . . 8
1.2.2 Equation of motion with additional RF field . . . . 10
1.2.3 Susceptibility tensor . . . . . . . . . . . . . . . . . 12
1.2.4 Losses . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.2.5 Resonance linewidth . . . . . . . . . . . . . . . . . 14
1.2.6 Permeability tensor for saturated materials . . . . 15
1.3 Microscopic scale for finite material . . . . . . . . . . . . . 16
1.4 Permeability tensor for ferromagnetic NWs . . . . . . . . . 20
1.5 Permeability tensor of unsaturated materials . . . . . . . . 23
1.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2 Modeling of nanowired templates 29
2.1 Topology of nanowired substrate . . . . . . . . . . . . . . 30
2.2 Permittivity model . . . . . . . . . . . . . . . . . . . . . . 31
2.3 Permeability model . . . . . . . . . . . . . . . . . . . . . . 37
2.3.1 Volumetric approach . . . . . . . . . . . . . . . . . 37
2.3.2 Variational approach . . . . . . . . . . . . . . . . . 39
2.4 Magneto-inductive model . . . . . . . . . . . . . . . . . . 45
2.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
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3 Model validation using transmission lines 53
3.1 Fabrication process of nanowired substrates . . . . . . . . 53
3.2 Device realisation using masking techniques . . . . . . . . 55
3.3 Transmission lines on PC . . . . . . . . . . . . . . . . . . 57
3.3.1 Validation of permittivity model . . . . . . . . . . 57
3.3.2 Validation of permeability models . . . . . . . . . . 61
3.3.2.1 Variational Approach . . . . . . . . . . . 62
3.3.2.2 Volumetric Approach . . . . . . . . . . . 64
3.3.3 Discussion of permeability models . . . . . . . . . 64
3.3.3.1 Tunability . . . . . . . . . . . . . . . . . 66
3.4 Transmission lines on alumina . . . . . . . . . . . . . . . . 67
3.4.1 Coplanar waveguide . . . . . . . . . . . . . . . . . 67
3.4.2 Metallic rectangular waveguide . . . . . . . . . . . 74
3.5 LH TLs using ferromagnetic nanowired substrate . . . . . 79
3.5.1 Concept of left-handed devices . . . . . . . . . . . 80
3.5.2 Simulations of tunable LH device . . . . . . . . . . 83
3.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
4 Applications of nanowired substrates 91
4.1 Integrated inductor . . . . . . . . . . . . . . . . . . . . . . 91
4.1.1 Inductor samples . . . . . . . . . . . . . . . . . . . 93
4.1.2 Validation . . . . . . . . . . . . . . . . . . . . . . . 93
4.1.3 Improvements . . . . . . . . . . . . . . . . . . . . . 97
4.1.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . 99
4.2 Circulator . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
4.2.1 Analytical modeling . . . . . . . . . . . . . . . . . 101
4.2.2 Model verification . . . . . . . . . . . . . . . . . . 104
4.2.3 Conclusion . . . . . . . . . . . . . . . . . . . . . . 106
4.3 Non-reciprocal microstrip lines . . . . . . . . . . . . . . . 107
4.3.1 Operating principle . . . . . . . . . . . . . . . . . . 108
4.3.2 State-of-the-art . . . . . . . . . . . . . . . . . . . . 109
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4.3.3 Field distribution . . . . . . . . . . . . . . . . . . . 110
4.3.4 Topology of ferromagnetic nanowired concept . . . 116
4.3.5 Fabrication process . . . . . . . . . . . . . . . . . . 118
4.3.6 Simulations . . . . . . . . . . . . . . . . . . . . . . 119
4.3.6.1 Influence of permittivity in zone 2 . . . . 120
4.3.6.2 Influence of permittivity in zone 3 . . . . 123
4.3.6.3 Influence of ferromagnetic zone width . . 126
4.3.6.4 Conclusion . . . . . . . . . . . . . . . . . 128
4.3.7 Experimental verification . . . . . . . . . . . . . . 128
4.3.7.1 Non-reciprocal lines on Co nanowired
substrate . . . . . . . . . . . . . . . . . . 128
4.3.7.2 Discussion . . . . . . . . . . . . . . . . . 132
4.3.7.3 Non-reciprocal lines on Ni nanowired
substrate . . . . . . . . . . . . . . . . . . 134
4.3.8 Additional verifications . . . . . . . . . . . . . . . . 136
4.3.9 Conclusion . . . . . . . . . . . . . . . . . . . . . . 139
4.4 Leaky-wave antenna . . . . . . . . . . . . . . . . . . . . . 141
4.4.1 LH antenna on ferromagnetic nanowired substrate 142
4.4.2 Frequency tuning . . . . . . . . . . . . . . . . . . . 145
4.4.3 Magnetic field tuning . . . . . . . . . . . . . . . . . 146
4.4.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . 147
Conclusion 152
A Unit conversion from MKS to CGS system I
B Verification of trial fields III
C Process Flow of Alumina Membranes V
D Conversion S-Parameter in ABCD VII