This work presents a single-chip low power transmitter realized in a 0.18 ㎛ CMOS process for 2.4GHz ZigBee Application. Among the various transmitter architectures, single IF direct conversion transmitter (DCT) and is a viable candidate solution for low cost and low power. And in this work, receiver is implemented in single IF direct conversion receiver (DCR) to alleviate various problems in relation to DCR such as large DC offset, LO leakage. Thus transmitter architecture also must be single IF direct conversion transmitter (DCT) to realize RF one-chip solution. It consumes only 30mW in transmission mode adopting circuit techniques suitable to new proposed transmitter architecture.