Differential Antennas

About the Author Preface Acknowledgement Chapter 1 Introduction 1.1 Background 1.2 Balanced and unbalanced antennas 1.3 Even and odd modes 1.4 Differential and single-ended circuits 1.5 An important ratio 1.6 Mixed-mode S-parameters 1.7 Balun 1.8 Concluding Remarks References Chapter 2 Differential Wire Antennas 2.1 Introduction 2.2 Dipole and monopole antennas 2.3 Folded dipole and folded monopole antennas 2.4 Loop and half-loop antennas 2.5 Loop-dipole and half-loop-monopole antennas 2.6 Yagi-Uda and half Yagi-Uda antennas 2.7 Concluding remarks References Chapter 3 Differential Slot Antennas 3.1 Introduction 3.2 Slot and half-slot antennas 3.2.1 The input impedances 3.2.2 The radiation characteristics 3.3 Self-complementary antennas 3.4 Yin-Yang antennas 3.4.1 Basic differential structure 3.4.2 The array model and the distribution of current 3.4.3 The electromagnetic field 3.4.4 The input impedance 3.4.5 The radiation characteristics 3.4.6  Basic single-ended structure 3.5 Concluding remarks References Chapter 4 Differential Microstrip Patch Antennas 4.1 Introduction 4.2 Cavity model 4.2.1 Electrically thin or thick substrate 4.2.2 Fields in the cavity 4.2.3 Radiation fields 4.2.4 Polarization 4.2.5 Directivity and radiation efficiency 4.2.6 Input impedances 4.2.7 Reflection coefficients 4.2.8 Resonance and electrical separation 4.2.9 Quality factor and VSWR bandwidth 4.3 Rectangular patch 4.3.1 Resonant modes 4.3.2 Resonant frequencies 4.3.3 Radiation characteristics 4.3.3.1 Radiated fields 4.3.3.2 Cross polarization 4.3.3.3 Radiation conductance and directivity 4.3.3.4 Radiation efficiency and effective loss tangent 4.3.4 Impedance characteristics 4.3.4.1 Differential input impedance 4.3.4.2 Fundamental resonance and electrical separation 4.3.4.3 Resonant differential input resistance 4.3.5 Quality factor 4.3.6 Differential versus single-ended rectangular microstrip patch antennas 4.3.6.1 Excitation and suppression of resonant modes 4.3.6.2 Input impedance ratio 4.3.6.3 Reduction of cross-polarized radiation 4.3.6.4 Performance improvement 4.3.7 Design procedure 4.4 Circular patch 4.4.1 Resonant modes 4.4.2 Resonant frequencies 4.4.3 Radiation characteristics 4.4.3.1 Radiated fields 4.4.3.2 Cross polarization 4.4.3.3 Radiation conductance and directivity 4.4.3.4 Radiation efficiency and effective loss tangent 4.4.4 Impedance characteristics 4.4.4.1 Differential input impedance 4.4.4.2 Fundamental resonance and electrical separation 4.4.4.3 Resonant differential input resistance 4.4.5 Quality factor 4.4.6 Differential versus single-ended circular microstrip patch antennas 4.4.6.1 Excitation and suppression of resonant modes 4.4.6.2 Input impedance ratio 4.4.6.3 Reduction of cross polarized radiation 4.4.6.4 Axial ratio improvement 4.4.7 Design procedure 4.4.7.1 Design for linear polarization 4.4.7.2 Design for circular polarization 4.5 Stacked patch 4.6.1 Quasi even and odd modes 4.6.2 Resonant frequencies 4.6.3 Design and optimization 4.6.4 Design examples 4.6.5 Results and discussion 4.6 Patch arrays 4.6.1 Feed networks 4.6.2 Mutual coupling 4.6.3 Reduction of mutual coupling 4.6.3.1 Modification to the patch, substrate, or ground plane 4.6.3.2 Integration of electromagnetic bandgap structures 4.6.3.3 Utilization of additional structures 4.6.4 Design considerations 4.6.4.1 Frequency scanning array 4.6.4.2 Phased array 4.6.4.2.1 A differential architecture from circuits to antennas 4.6.4.2.2 The use of baluns in the feed network 4.7 Applications 4.8 Concluding remarks References Chapter 5 Differential Microstrip Shorted Patch Antennas 5.1 Introduction 5.2 Basic SPA and DSPA  5.2.1 Resonant modes  5.2.2 Coupling and resonance  5.2.3 Radiation characteristics  5.2.4 Frequency ratio and size reduction  5.2.5 Experiment results 5.3 Modified SPA and DSPA  5.3.1 Radiation Characteristics  5.3.2 Design and experiment 5.4 PIFA and DPIFA  5.4.1 Analysis and design  5.4.2 Experiment 5.5 ME and DME dipoles  5.5.1 Feeding techniques  5.5.2 Resonant frequency  5.5.3 Operating principle  5.5.4 Design of DME dipole and array  5.5.5 ME dipole array applications 5.6 Concluding remarks References Chapter 6 Differential Microstrip Slot Antennas 6.1 Introduction 6.2 Resonant modes 6.3 Excitation of resonant modes 6.4 Half-wavelength microstrip slot antennas 6.5 Full-wavelength microstrip slot antennas 6.6 Concluding remarks References Chapter 7 Differential Microstrip Grid Array Antennas 7.1 Introduction 7.2 Basic configuration 7.3 Principle of operation 7.4 Fundamental characteristics  7.4.1 Resonant frequency  7.4.2 Impedance bandwidth  7.4.3 Half-power beamwidth  7.4.4 Gain  7.4.5 Gain bandwidth 7.5 Differential excitation 7.6 Design procedure, formulas, and examples 7.7 An impedance matching technique 7.8 A slow-wave structure 7.9 Dual current modes 7.10 Co-aperture dual bands 7.11 Applications  7.11.1 60-GHz radios  7.11.2 79-GHz radars   7.11.3 Full duplex radios and MIMO systems   7.11.4 RF energy harvester and wireless power transfer 7.12 Concluding remarks References Chapter 8 Differential Printed Antennas 8.1 Introduction 8.2 Quasi-Yagi Antennas  8.2.1 Surface wave  8.2.1.1 Guided by grounded dielectric substrate  8.2.1.2 Guided by ungrounded dielectric substrate  8.2.2 Design of differential quasi-Yagi antenna  8.2.3 Quasi-Yagi antenna Arrays  8.2.3.1 Mutual Coupling  8.2.3.2 Decoupling Structures and Effects 8.3 Fractal Antennas  8.3.1 The Sierpinski gasket monopoles  8.3.1.1 The original Sierpinski gasket monopole  8.3.1.2 Design formulas  8.3.1.3 A Sierpinski gasket monopole fed by a microstrip line  8.3.2 The Sierpinski gasket dipoles 8.4 Spiral Antennas  8.4.1 The equiangular spiral antenna  8.4.1.1 Frequency independence  8.4.1.2 Current distributions  8.4.1.3 Input impedance  8.4.1.4 Radiation patterns  8.4.1.5 Gain 8.5 Applications 8.6 Concluding Remarks References Chapter 9 Differential Antenna Measurements 9.1 Introduction 9.2 Impedance  9.2.1 The S-parameters method  9.2.2 The balun method  9.2.3 The mixed-mode S-parameters method  9.2.4 Comparison of the methods 9.3 Efficiency  9.3.1 The Wheeler cap method  9.3.2 The source-stirred chamber method 9.4 Radiation pattern 9.5 Gain 9.6 Concluding remarks References Index