Design and fabrication of 4bit phase shifter for use in 5.4∼5.9GHz frequency range are presented. The loaded line type is used for 22.5°, 45° and reflection type for 90°, 180°. The chip to die interconnection is accomplished by utilizing flip-chip technology. One experimental results show that flip-chip technique gives much more predictable and reliable results compared with wire bonding. Thus it guarantees very high yield, even for the phase shifter, where slight variation in wire bonding length leads to very large phase error. Compared with simulation results, we obtained less than 2.5° phase error and less than 0.3dB insertion loss error for 45° phase shifter.
