Abstract: Phase shifter is fundamental element in transmit/receive module of RF frontend. In defence application phase shifters have been widely used in phased array antennas. But commercially they are not used widely due to its costs. Various parameters have been presented in the paper that deals with different types of phase shifter both analog and digital. Insertion loss, return loss and bandwidth are key parameters. Microstrip line, strip line and slotted strip line can be used in commercial applications as they provide lower cost design.

Keywords: Phased array antennas, transmission line phase shifters, transverse electromagnetic (TEM), reflection type, loaded line, switched line, switched network, quadrature hybrid, lange coupler.