Antenna Pattern Characteristics of Fine-Steered Pencil Beams,
RAYTHEON CO WAYLAND MA MICROWAVE/ANTENNA DEPT
Pagination or Media Count:
When a set of simultaneous pencil beams is available from a multiple beam forming network exciting a linear array, it is possible to fine steer a single beam to any far-field angle within the field of view by approximately combining the signals of selected network beam ports. This paper considers the problem of determining the beam port combining weights required to point a resultant beam at a preselected far-field angle with some measure of control on its aperture efficiency and its highest sidelobe level. A set of orthogonal, in-phase, uniformly excited pencil beams as might be obtained by feeding a linear array through a Butler matrix is discussed in detail. In particular, examples of combining three and four adjacent beams are shown where the combining weights are adjusted to provide a resultant beam at a specified angle located between the pointing directions of two linear orthogonal beams and such that this resultant beam has a specified aperture efficiency and a controlled sidelobe level for one chosen near-in sidelobe.