Design and Implementation of Phase Shifter for Wireless Communication

Abstract

Abstract: Phase shifters are common microwave devices that are widely used to control the phase of a microwave signal in mobile satellite systems, microwave instrumentation and measurement systems, modulators, noise cancellation systems, frequency converters, electronic beam scanning phase arrays, microwave imaging, and many other industrial applications is used for. Phase shifters are passive devices used to perform variable phase changes in the wave propagating through it. Phase shifters require compact size, low cost and low insertion loss in the desired bandwidth. The size of the phase shifters is a crucial parameter, especially in the design of portable microwave devices, due to the space constraints. The significantly higher insertion loss of phase shifters used in a transmitter causes a significant reduction in transmitting power levels, while it causes a severe drop in signal to noise ratio when the phase shifter is a part of the receiver.. Phase shifters are essential components in phased array antennas for wireless and Radio Detection And Ranging (RADAR) applications. Loaded line phase shifter, reflective line phase shifter and switched line phase shifters are the most commonly used. The electrical performance of a phase shifter is specified in terms of insertion loss, phase error, operating bandwidth and power handling capacity.. Emerging wireless systems have transceivers that require compact and cost effective phase shifters. Physical size and weight of phase shifters are the major issues in mobile and the wireless applications. Therefore, miniaturization of phase shifters has become an important objective of radio frequency (RF) designers to provide portability and affordability in wireless/mobile systems. The present research work mainly focuses on planar phase shifter design with linear phase shift. In this a Defected Ground Structures (DGS) is proposed where as ,Monolithic Microwave Integrated Circuits (MMIC), Micro Electro Mechanical Systems (MEMS) and fractals have emerged as the possible techniques for miniaturization of RF systems and antennas. However the existence of defected cells on the ground plane may limit the use of DGS based phase shifters. MMIC technology increases the cost and complexity of manufacturing whereas MEMS based phase shifter is prone to limited life and yield. In this thesis, fractal techniques are adapted to design and develop miniaturized phase shifters for wireless applications.