This paper proposed a versatile signal generator which employed a phase lock loop (PLL) chip and a direct digital synthesizer (DDS) chip to produce microwave signal for 3G mobile communication jamming. Based on the self-developed software, it could be controlled to produce single frequency, amplitude modulation (AM), frequency shift keying (FSK) or binary phase shift keying (BPSK) signal for different effective jamming applications. For different configuration or small changes, it could be used for other applications. ...