Design of Microstrip Antennas for Wideband Applications

Microstrip or patch antennas are getting to be progressively valuable on the grounds that they can be printed specifically onto a circuit board. They are broadly utilized as a part of flying machines, satellites, mobile, wireless application where size, weight, cost, ease of installation, aerodynamic profile are constraints, low profile like microstrip antennas may be needed. Hence design and development of cost effective and superior microstrip patch antenna has become an active research area. The size reduction and impedance bandwidth improvement lies in great importance in today’s life.This thesis presents design of microstrip antennas for wireless applications. Four antennas designed are presented in the following chapters. The first design is a compact dual band microstrip antenna which produces dual band characteristics. The second design is a compact wideband microstrip antenna that has wideband characteristics which have applications in health care,medical field like health monitoring and imaging in intensive health care units,pediatric units,emergency situation like heart beat rescue. The third one is the Design of circularly polarized microstrip patch antenna using a pair of inserted slits. The fourth one is the design of hexagonal shaped patch antenna using coplanar waveguide feed. The antennas designed above have better radiation characteristics with improved bandwidth

Mamdani Fuzzy Expert System Based Directional Relaying Approach for Six-Phase Transmission Line

Traditional directional relaying methods for 6-phase transmission lines have complex effort, and so there is still a need for novel direction relaying estimation scheme. This study presents a Mamdani-fuzzy expert system (MFES) approach for discriminating faulty section/zone, classifying faults and locating faults in 6-phase transmission lines. The 6-phase fundamental component of currents, voltages and phase angles are captured at single bus and are used in the protection scheme. Simulation results substantiate that the protection scheme is very successful against many parameters such as different fault types, fault resistances, transmission line fault locations and inception angles. A large number of fault case studies have been carried out to evaluate reach setting and % error of proposed method. It provides primary protection to transmission line length and also offers backup protection for a reverse section of transmission line. The experimental results show that the scheme performs better than the other schemes