Abstract
In recent years, following the introducing of state of the communication products, demands for power devices have risen substantially. In keeping with the trend of circuit integration, traditional vertical device needs to be changed to lateral structure to make it possible for the integration of power devices and low voltage circuit on the same chip. LDMOSFET transistor is one of the most important high power devices for commercial communication applications and RF circuit. It is very important to set up an accurately model which contains the high frequency and it is helpful to design a RF circuit composed of these transistors. This thesis contains both the small-signal modeling methods of RF LDMOSFET device. Utilizing high frequency measurement method, extrinsic parameters of device can be extracted. And then using matrix operation method to obtain intrinsic parameters of the device, and set up the small-signal equivalent model of the transistor and this thesis presents comprehensive methods for the application of RF LDMOSFET Transmit/Receive switch with high power-handling capability and low insertion loss and Utilizing extracted parameters of LDMOSFET device and set up the equivalent model of the RF Switch Circuit. The model simulates the operation modes of RF Switch Circuit. The good agreement between measured and modeled S parameters justifies the accuracy of our equivalent circuit model. RF power device based on a 0.25μm LDMOSFET process at 900MHz. The measured performance of gain up to 10dB, input 1-dB compression point of 16.7dBm and the power output up to 27dBm can be achieved. The RF switch circuit implemented using 0.25μm LDMOSFET transistors for 900MHz wireless application have been present. In particular, 900MHz switch with the measured insertion loss less than 1 dB, isolation up to 20dB and input third-order intercept point of 25 dBm.