Design of a zero crossing BFSK demodulator for a wireless sensor

In this paper, a transistor-level simulation result of a Zero crossing BFSK demodulator is presented. The detector will be integrated into a frequency-hopped spread spectrum receiver operating in the 863-870 MHz ISM band, using the zigbee protocol (IEEE 802.15.4). This end to demodulate a received bit sequence with a bit rate equal to 20 kbps using 0.35 μm CMOS technology and a 3 V power supply. The proposed demodulator dedicated to an application of low power and low cost can maintain good performance under process variation. The BER results show that the proposed demodulator needs only 10.9 dB input signal_to_noise ratio to achieve a BER of 10-3 as specified in zigbee standard.