Disclosed herein is a multi-band ZigBee transceiver for supporting IEEE
802.15.4 wireless communications. In the multi-band ZigBee transceiver, a
Multi-Mode Modem (MMM) selects any one of a European version standard
using 860 MHz band, a US version standard using 920 MHz band, and a
worldwide version standard using 2.4 GHz ISM band among IEEE 802.15.4
standards. A frequency synthesizing unit variably adjusts a carrier
frequency according to the transmission standard. A transmission unit
receives a digital modulated signal, low-pass-filters the digital
modulated signal with a bandwidth thereof being variably adjusted, and
up-converts the filtered digital modulated signal into an RF modulated
signal corresponding to the selected transmission channel. A receiving
unit down-converts the RF modulated signal into a BB modulated signal
using the carrier frequency, low-pass-filters the BB modulated signal
with a bandwidth thereof being variably adjusted according to the
selected transmission standard, converts the filtered BB modulated signal
into a digital modulated signal, and outputs the digital modulated signal
to the MMM. A transmission/reception switch unit outputs the RF modulated
signal, input from the transmission unit, to an antenna, or outputs the
RF modulated signal, received from the antenna, to the receiving unit.