Abstract
This thesis presents the design of a fully digital controlled binary frequency-shift- keying (BFSK) RF transmitter for 2.4 GHz wireless applications. Instead of traditional voltage controlled oscillator (VCO), a digitally controlled oscillator (DCO) with three switched-capacitor arrays adopts as a core of this RF transmitter. There are two digital feedback loops to control the DCO to perform the BFSK transmission. Before data transmitting, the DCO codes for both logic-1 and logic-0 frequencies are generated and stored by a binary-searching digital calibration loop. When data modulating and transmitting, another digital phase-locked loop (PLL) is enabled to cancel the frequency shift induces by long-time operation. The designed transmitter is implemented in TSMC 0.18 μm CMOS process, and the chip area is 1.1 × 1.1 mm2. According to the simulation results, the frequency tuning range is around 2.36 ~ 2.59 GHz. The phase noise is about -110 dBc/Hz at 500 kHz offset frequency. For 250-kHz data-rate transmission, the frequency error is less than 100 kHz. The total power consumption is around 13 mW under 1.8 V power supply.