Phase shifter design & Research study and verification of wideband phase shifter circuits

Abstract: Radio Frequency waves are widely used for the purpose of radio communication. Active research in Radio Frequency technology has led to the use of RF waves in variety of application other than radio communication. Phase shifters are a major functional block in RF transmission circuits. In radio communication, phase shifters are used for electronic beam steering of the transmitted RF waves. Due to the increase in RF application area, there is a demand for phase shifters which have high performance with very less cost and also very less power consumption. This thesis work focuses on designing phase shifters for different ISM frequency bands. This thesis work has been divided into two sections. The first section focuses on building a discrete phase shifter circuit which has very high performance with less cost and less power consumption. This circuit can perform phase shifting function on RF waves with low power. This phase shifter circuit was built with four phase shifter sections and each of the section can be controlled individually by digital control bits. The phase shifter was designed to have a bandwidth of operation of 200MHz with a center frequency at 900MHz. Designed phase shifter achieved an minimum RMS phase error of 2.5 0 with a insertion loss variation throughout the bandwidth within 1.038dB. The second section of the thesis focuses on research study and verification of wide band phase shifter circuits. The aim of the research study was to find a suitable integrated circuit to cover a wide range of ISM bands (300MHz to 3GHz). Totally 22 research papers were compared and analyzed, out of which one circuit was chosen for this purpose. This circuit was verified by building system level circuit and thus critical design parameters were determined.