This paper proposes a sigma-delta fractional-N frequency synthesizer-based multi-standard I/Q carrier generation system.With reasonable frequency planning,the system can be used in multi-standard wireless communication applications(GSM,WCDMA,GPRS,TD-SCDMA,WLAN(802.11a/b/g)).The implementation is achieved by a 0.13μm RF CMOS process.The measured results demonstrate that three quadrature VCOs(QVCO) continuously cover the frequency from 3.1 to 6.1 GHz(65.2%),and through the successive divide-by-2 prescalers to achieve the frequency from 0.75 to 6.1 GHz continuously.The chip was fully integrated with the exception of an off-chip filter.The entire chip area is only 3.78 mm~2,and the system consumes a 21.7 mA@1.2 V supply without output buffers.The lock-in time of the PLL frequency synthesizer is less than 4μs over the entire frequency range with a direct frequency presetting technique and the auxiliary non-volatile memory(NVM)can store the digital configuration signal of the system,including presetting signals to avoid the calibration process case by case. This paper proposes a sigma-delta fractional-N frequency synthesizer-based multi-standard I / Q carrier generation system. With reasonable frequency planning, the system can be used in multi-standard wireless communication applications (GSM, WCDMA, GPRS, TD- SCDMA, WLAN (802.11a / b / g)). The implementation is achieved by a 0.13 μm RF CMOS process. The measured results demonstrate that the three quadrature VCOs (QVCO) and through the successive divide-by-2 prescalers to achieve the frequency from 0.75 to 6.1 GHz continuously. The chip was fully integrated with the exception of an off-chip filter. The entire chip area is only 3.78 mm ~ 2, and the system consumes a 21.7 mA@1.2 V supply without output buffers. The lock-in time of the PLL frequency synthesizer is less than 4μs over the entire frequency range with a direct frequency presetting technique and an auxiliary non-volatile memory (NVM) can store the digital configuration signal of the system, includ ing presetting signals to avoid the calibration process case by case.