Abstract: An antenna apparatus for generating transmit signals, receiving return signals based on the transmit signals, and/or receive transmitted signals from other sources is provided. The antenna apparatus includes a beam forming system and a beam collimating system. The beam forming system includes an array of feed elements. Each feed element can be used to generate more than one primary beam, either substantially at the same time or at different times. A secondary beam is developed from the primary beam using the collimating system. The secondary beam constitutes the transmit signal. The feed elements have relatively low gain, the spacing between them is no greater than about one wavelength, and they are relatively small in size to reduce beam-to-beam cross over loss. The beam forming system also includes a control system for energizing different feed elements using the same transmit/receive modules.