Design, Analysis and Mathematical Modelling of Wideband Phase Shifter

Abstract

A phaseshifter is a device that changes the phase of a signal. When a wave is made to pass through it, it provides a phase variation in the wave at its output ports [1]. Phaseshifters can be designed to provide any phase shift between the output ports by changing the dimensions of phaseshifter. In many microwave applications phase shifter is a critical component. It nd its applications mainly in phased array antenna and beam forming networks. Phased array antenna can control the direction of wave beam without the need to change the position of antenna elements. Phased array antenna consists of many antenna elements. Each antenna element contain phaseshifter in them which control the phase of the signal that is entering the antenna system. Light weight, small size and low cost phaseshifters are important for designing the phased array antenna [2]. Another application of phaseshifter is that they are used in power division and coupling. In power division the power of the input signal can be divided into two output signals. Power division can be a equal power division or unequal power division. In power coupling power of two input signals are combined [3]. 1.1. Literature Review In [4], authors have replaced the branches of branch line coupler with dual transmission lines and partial meandering lines. The miniaturized coupler is operating at 1.675 GHz frequency. The presented design able to give the equal power division between two output ports Authors in [5] have replaced all the branches of conventional coupler with transmission line with three open circuited stubs from which one is center tapped and two are end-tapped open circuited stubs. Thereby achieving the reduced size with harmonic suppression. A branch line coupler was also designed operating at 1 GHz, which occupies 56% of circuit area of the conventional coupler In [6] new miniaturized branch line coupler is presented at 0.7 GHz frequency by using composite right/left handed transmission line structures which has meander shaped slots. The structure contained in 22.8% area of traditional coupler. In [7] authors have used dual transmission in place of quarter