For the instance of USB/IrDA network adapters,the collimating optical system is integrated on the infrared wireless interconnect card.Experimental results show that the transmission distance is expanded from 1.5 m to 4.1 m under Windows 98 environments and the efficient data transmission speed is also improved.Under Windows 2000 environment,the efficient data transmission speed is increased from 1.04 Mbps to 2.00 Mbps when the transmission distance is 2.0 m.