Abstract
In this thesis, a low-power multi-standard wireless transceiver for body area network is designed, analyzed and implemented. This transceiver contains a frequency synthesizer, a transmitter, a receiver and a digital baseband processor. The physical layer and the recon- figurable baseband support standards of Bluetooth low energy (BT-LE), ZigBee and IEEE 802.15.6 Narrow Band(NB). The receiver in ZigBee and IEEE 802.15.6 modes uses direct conversion with quadrature path to avoid bulky saw filter. In BT-LE operation, a single path low-IF architecture with a lowpass filter is chosen while the IF is at half signal bandwidth. The passive LNA and mixer are adopted in RF front-end to have lowest power consumption under moderate noise performance requirement. The following analog circuits have variable gain amplifiers (VGAs) and tunable lowpass filters to satisfy the requirements for different standards. One of the quadrature path in mixer and analog baseband circuits can be shut down for power saving in the BT-LE mode. The frequency synthesizer uses an integer-N PLL. The VCO oscillates at twice of RF frequency. The quadrature phases are further generated by the divide-by-two function. Dur- ing BT-LE and IEEE 802.15.6 transmitting, the frequency modulation signal is fed into VCO without closed-loop control of PLL. To satisfy the variable-envelope signal for IEEE 802.15.6, the instantaneous amplitude information modulates the digitally controlled power amplifier (DCPA), directly. Thus, the modulation scheme can be synthesized by frequency modulation from VCO and amplitude modulation from DCPA. This work implemented in a 0.18µm CMOS technology occupies 2.8 × 2.1 mm 2 . The receiver achieves -63 dBm receiver input sensitivity (for 0.1% bit error rate) in BT-LE mode. 1The 6.77% EVM is measured for IEEE 802.15.6 at symbol rate of 600 kbps. Transmitting output power is dropped to -18 dBm due to the bondwire effects and corner process variation. The transceiver consumes 4.8mW/8.7mW during BTLE/802.15.6(ZigBee) receiving mode and 12mW during transmitting at -18dBm output power from a 1.2V supply voltage respectively.