| dc.description.abstract | The circuits based on CMOS technology achieve the advantages of low cost and high integration capability. However, because of low breakdown voltage and poor substrate insulation, it is difficult to design the high power circuits. This research employs body-floating technique, feed-forward capacitor technique, multi-stacked FET and low-substrate resistance technique to improve the RF switch’s insertion loss and power-handling capability. In order to improve CMOS models in high-power applications, this research modify the commercial BSIM3 model to consider the effects from body and substrate. So that, the high power T/R switch operating at 1.9 GHz can be designed and realized.
In addition, the high power tunable low-pass filter is designed by using CMOS technology and by controlling the gate voltage to change the state of the transistor and combining the capacitor to design the switched capacitor. At first, power-handling capability of the switched capacitor is simulated then combines the inductor to achieve the tunable low-pass filter for a 34 dBm power handling capability. Next, the tunable low-pass filter is turned into band-pass filter. This tunable band-pass filter’s power handling capability is greater than 36 dBm with tuning ratio of 62%.
Finally, a high power tunable filter is further designed by using 0.5 μm GaN on silicon process. The tunable low pass filters are constituted by shunt type switched capacitor and series type capacitor respectively. When operating at 2 GHz, the power-handling is greater than 36 dBm with very low insertion loss. | en_US |