The X-band flat-plate antenna from Cobham Antenna Systems operates from 7.25 - 8.4 GHz (both ports). It has been developed for on the move applications and uses a novel, high performance, low loss construction to minimize size, weight and cost. The antenna concept is based on a multilayer PCB that does not require via holes or machined parts within the structure. The components in the receive chain, including the LNB, are mounted on the back of the aperture. The LNB is a stand-alone LRU that can be removed and replaced independently of the radiating aperture itself. The antenna has a gain of over 29 dBi (Rx) and over 29.5 dB (Tx) with dual orthogonal polarization from seperate ports. The apeture size is 844 x 231 mm and the antenna has N Type Female connectors (Rx) and SMA Female connectors (Tx). The RF components of the transmit chain are also mounted on the back of the antenna, with the exception of the power amplifier, in order to maintain symmetry and balance. The aperure is suitable for mounting on elevataion over azimuth positioners.