In this paper, 5.8 GHz ASK (Amplitude Shift Keying) RF module for DSRC (Dedicated Short Range Communication) packet communication system which has been developed by ETRI is described. Design specification of ASK RF module is considered to meet 2.048 Mbps packet data transmission and 8 MHz channel bandwidth within 100 m radio cell. It is operated in TDD (Time Division Duplex) mode and may be commonly applied for RSE (Road Side Equipment) side and OBE (On-Board Equipment) side. Patch antenna provides two types of spot beam according to ITS applications such as ETC (Electronic Toll Collection) and BIS (Bus Information System), etc. ASK RF module is implemented by direct RF ASK and envelope detection via RF down conversion. RF module testing includes Tx power spectrum and BER (Bit Error Rate) measurement at Rx sensitivity signal level, and field test while driving. For the covering abstract see ITRD E114174.