Reconfigurable Active and Passive Planar Antennas for Wireless Communication Systems

This book presents state-of-the-art trends in reconfigurable active and passive planar antennas and their applications in wireless communication systems operating in the frequency band 5-6 GHz. Due to various key features such as multifunction antenna design, compactness, planar nature, and low cost, these technologies are becoming popular for current and future wireless applications. This book discusses different novel antenna designs and their working principles in detail. The modern and future wireless systems require wideband antennas to accommodate various channels in a single band or in separate bands. The carrier aggregation (CA) has been introduced in the modern wireless systems such as LTE-advanced systems and 5G./6G. In CA, a device can use several channels for transmission and reception. The used channels can exist in the same frequency band (intra-band CA) or in distinct bands (inter-band CA). To accommodate more channels, more bandwidth is required within the operating band. For portable devices, circularly polarized (CP) antennas are more advantageous over linearly polarized antennas since in CP antennas, there is low risk of misalignment and, hence encountering interference. Circularly polarized antenna also provides higher link reliability for the portable devices. To provide high data rates, more bandwidth is needed to accommodate more channels. Various multifunction, compact, and wideband antennas for plethora of applications are addressed in detail in this book. The scope of developing reconfigurable active antennas for application in beam switching, beam steering, wireless charging, security systems, etc., is described. This book concludes by giving glimpses of antenna requirements for future wireless communication systems.

1.                  Introduction

            1.2       Planar Antennas

                        1.2.1    Passive Antennas

            1.3       Advantages of Planar Antennas

            1.5     Switch Modeling Techniques

References

2.              2     Principles of Re-configurability

            2.1       Introduction

            2.2       Basic Theory of Reconfigurability

            2.3       Frequency Reconfigurability

            2.4       Polarization Reconfigurability

            2.5       Radiation Pattern Reconfigurability

            2.6       Compound Reconfigurability

            2.7       Conclusion

  3.       Active Integrated Antennas and Their Modeling

            3.2       Oscillator Type Active Antennas

3.3       Condition of Oscillation

3.4       Negative Resistance Type Oscillator antennas

3.5       Feedback Type Oscillator Antennas

3.6       Advantages of Feedback Type Oscillator Antennas

3.7       Conclusion

                        References

            4.1       Introduction

            4.2       Passive Reconfigurable Antenna using different approaches

            4.3       Discrete Frequency Switchable Antennas

            4.4       Continuous Frequency switchable Antennas

            4.5       Concept of Obtaining Higher and Lower Resonance

            4.6       Active Reconfigurable Antennas using different approaches

            4.7       Conclusion

                        References

5.         Polarization Switchable Passive and Active Antennas

5.2       Concept of polarization

                        5.3.1    Design with a Pair of Diagonally Truncated Corners

                        5.3.2    Design with a Single Truncated Corner

                        5.3.3    Design with a Stub Placed at Corner

                        5.3.4    Design with an additional Patch

                        5.4.1    Design of Narrow band antennas

                        5.4.2 Design of Wideband Antennas

            5.5       Active Reconfigurable Microstrip Antenna using different approaches

            5.6       Conclusion

                        References

 6.        Radiation Pattern Reconfigurable Passive and Active

        Antennas

            6.1       Introduction

            6.2       Concept of Radiation Beam Reconfigurability in Antennas

            6.3       Passive Beam Reconfigurable Antennas

            6.5       Active Beam Reconfigurable Antennas