Contents
List of papers ... 13
1. Introduction... 17
1.1. Significance of the research... 17
1.2. Scientific goals and organization of the Thesis ... 18
2. Dual-polarized series-fed antenna arrays ... 21
2.1. Series-fed microstrip antenna lattice with switched polarization utilizing Butler matrix [1] 24 2.2. Bandwidth enhancement of dual-polarized microstrip antenna lattice [2]... 32
2.3. Modified series-fed dual-polarized antenna lattice with improved bandwidth [3]... 36
2.4. Compact integrated feeding network for excitation of dual-circular polarization in series-fed antenna lattice [4]... 38
2.5. Dual polarized two-port antenna lattice [5] ... 42
2.6. Integrated feeding network for excitation of dual-linear polarization in series-fed antenna lattice [6] ... 46
2.7. Symmetrical series-fed dual-polarised microstrip antenna lattice with odd number of radiating elements [7] ... 49
3. Multiple beam antenna arrays with passive beam-forming networks ... 57
3.1. Integrated two-beam antenna array featuring dual-circular polarization [8]... 61
3.2. Single-layer four-beam microstrip antenna array [9] ... 63
3.3. Folded single-layer 8× 8 Butler matrix [10] ... 66
3.4. Circularly polarized switched-beam antenna arrays with reduced sidelobe level [11] ... 79
3.5. Experimental verification of sidelobe level reduction technique for circularly polarized antenna array fed by 8× 8 Butler matrix [12] ... 83
3.6. Linear-polarized three-beam four-element antenna array with reduced sidelobe level [13] . 87 3.7. Scalable multibeam antenna arrays fed by dual-band modified Butler matrices [14]... 89
4. Leaky-wave antennas with improved beam-scanning sensitivity to frequency change...101
4.1. Composite right/left-handed leaky-wave antenna with adjustable radiation bandwidth [15]104 4.2. Composite right-/left-handed leaky-wave antenna utilizing coupled-line sections [16] ...114
4.3. Empirical technique for meeting balance condition of coupled-line leaky-wave antenna [17] ...127
12 Contents
4.4. Novel balanced coupled-line leaky-wave antenna without equalization of phase
velocities [18] ...129
4.5. Planar composite right/left-handed leaky-wave antenna featuring dual beam [19] ...131
5. Summary...137
Author’s Achievements...141
Bibliography ...153
