A receiving and transmitting device for wireless transceivers is revealed. The device has been developed from a high isolation MIMO (multiple-input multiple-output) antenna used for 2.45 GHz WLAN operation. The antenna is a dual-fed coupled monopole MIMO antenna that includes a dielectric substrate and a MIMO antenna. A grounding portion with two signal ends for feeding signals is disposed on the dielectric substrate. A T-shaped metal plate is extended from the grounding portion and located between two signal ends. A C-shaped parasitic element is arranged at the metal plate and there is a certain distance therebetween so as to adjust the isolation. The antenna is symmetrical for improving isolation and is suitable for USB dongles or small-sized wireless mobile devices.