Abstract: A radiometer horn, an array of such horns, and a method of making a radiometer horn, comprising providing at least two primary walls comprising interior corrugations and fitting into the corrugations at least one secondary wall comprising projections fitting into the corrugations, and wherein no fastener holds any of the at least one secondary walls to the primary walls.

Abstract: The present invention relates to a method and apparatus for selectively receiving radio frequency (RF) signals which utilizes an array of antenna elements including a center antenna for receiving the RF signal, a navigational controller using coordinate information to determine pointing vectors pointing to respective RF signal sources, and beam-forming electronics connected to the array of antenna elements and the navigational controller for forming reception lobes. Each reception lobe points in the direction of a determined pointing vector. For accurate and precise measurements, a constant phase center is maintained by adjusting the center antenna to the same phase shift for each of the lobes and steering the lobes by adjusting the phase shift of the antenna elements surrounding the center antenna.

Abstract: The present invention relates to a method and apparatus for selectively receiving a radio frequency (RF) signal which utilizes an array of antenna elements for receiving the RF signal, a navigational controller for determining a pointing vector from coordinate information, and beam-forming electronics connected to the array of antenna elements and the navigational controller for forming reception lobes. This apparatus and method are particularly useful in the context of a Global Positioning System (GPS) for selectively receiving RF signals from GPS satellites to determine location and timing information. In one embodiment of the present invention, the phase of the elements of the array are adjusted to form selective reception lobes and constructively amplify signals within these reception lobes, increasing the signal-to-noise ratio (SNR) with respect to noise or interference signals outside the lobes.