A modified 0.18 mum gate-length p-channel MOSFET large-signal rf model, based on the BSIM3v3 model, is presented in this report which achieves a good agreement with the device performance. This large-signal rf model includes the required passive components to fit the device dc and rf characteristics. To verify this modified model, the microwave load-pull and digital modulation evaluation have been conducted and compared them with the model predictions, where a good agreement has been reached for this 0.18 pm p-MOSFET. A 2.4 GHz fully integrated PMOS voltage-controlled oscillator (VCO) MMIC was designed based on this modified model. An accurate prediction of oscillation frequencies and output power levels of this 2.4 GHz PMOS VCO can be achieved, which demonstrates that the modified rf large-signal model can be applied for microwave circuit design. (C) 2003 Elsevier Science Ltd. All rights reserved.