A log periodic antenna system with conformal radiating elements includes a feed layer with phase shifters and filters associated with each radiating element. The filters may be low-pass or band-pass filters. The log periodic conformal radiating elements produce superior gain and bandwidth, and reduce directionality of the antenna at least along a radial axis of the antenna. Sets of conformal radiating elements are disposed on opposing sides of the antenna, or periodically around the surface of the antenna, to further reduce directionality.

A log periodic antenna system with conformal radiating elements includes a feed layer with phase shifters and filters associated with each radiating element. The filters may be low-pass or band-pass filters. The log periodic conformal radiating elements produce superior gain and bandwidth, and reduce directionality of the antenna at least along a radial axis of the antenna. Sets of conformal radiating elements are disposed on opposing sides of the antenna, or periodically around the surface of the antenna, to further reduce directionality.

A low-profile, ultra-wideband, conformal antenna is actively driven by a four-port quadrature feed circuit for both cardioid and monopole radiation patterns. The quadrature four-port and differential two-port driven radiating elements are organized into a log periodic array that is driven without frequency dispersion. The log periodic array may produce circularly polarized beams. For radiating elements that do not operate via a ground plane, stepped artificial magnetic conductors isolate the drive circuitry.

A low-profile, ultra-wideband, conformal antenna is actively driven by a four-port quadrature feed circuit for both cardioid and monopole radiation patterns. The quadrature four-port and differential two-port driven radiating elements are organized into a log periodic array that is driven without frequency dispersion. The log periodic array may produce circularly polarized beams. For radiating elements that do not operate via a ground plane, stepped artificial magnetic conductors isolate the drive circuitry.

An antenna system comprises first and second support structures, and a plurality of first, second and third antenna elements. Each of the first and second support structures has four sides. Two adjacent sides are perpendicular to each other so that both the first and second support structures form a closed loop. The first support structure is disposed outside of and surrounds the second support structure. Some first antenna elements are disposed on two symmetric sides of the first support structure, and other first antenna elements are disposed on two symmetric sides of the second support structure. Some second antenna elements are disposed on another two symmetric sides of the first support structure, and the other first antenna elements are disposed on another two symmetric sides of the second support structure. The third antenna elements are disposed on the four sides of the second support structure.

A broad band diversity antenna system comprises a system of log periodic antennas (LPA) and dipole antennas. Two LPAs form a balanced dipole by feeding the back ends of the LPA. The feed is improved by the addition of a balun to ensure RF balance. Because a dipole only requires narrow bandwidth, a simple balun is constructed from coax cable or a transmission line, thus providing low cost construction.

A broad band diversity antenna system comprises a system of log periodic antennas (LPA) and dipole antennas. Two LPAs form a balanced dipole by feeding the back ends of the LPA. The feed is improved by the addition of a balun to ensure RF balance. Because a dipole only requires narrow bandwidth, a simple balun is constructed from coax cable or a transmission line, thus providing low cost construction.

Antenna system includes a ground structure and a set of inverted-F antenna (IFA) elements that are configured to be fed by a feed network. Each of the IFA elements has an arm that is spaced apart from the ground structure by a designated height and extends along the ground structure for at least a portion of the arm. Each of the IFA elements has a shorting stub that is coupled to the arm and to the ground structure. The antenna system may be configured for wideband or multiband operation.

A log-periodic antenna including one set of three radiating elements with log-periodic patterns, each radiating element including a succession of radiating dipoles distributed on either side of a rectilinear electrically conducting line, perpendicular to the line, a first radiating element having a rectilinear electrically conducting line substantially perpendicular to the first face of the substrate, the first ends of the electrically conducting lines of the various radiating elements being substantially aligned along a direction parallel to the first face, the rectilinear electrically conducting lines of the second and third radiating elements being situated in a same plane as the rectilinear electrically conducting line of the first radiating element and inclined with respect to the electrically conducing line of the first radiating element, the radiating dipoles of the three radiating elements being substantially perpendicular to the plane which contains the rectilinear electrically conducting lines of the three radiating elements.

A log-periodic antenna including one set of three radiating elements with log-periodic patterns, each radiating element including a succession of radiating dipoles distributed on either side of a rectilinear electrically conducting line, perpendicular to the line, a first radiating element having a rectilinear electrically conducting line substantially perpendicular to the first face of the substrate, the first ends of the electrically conducting lines of the various radiating elements being substantially aligned along a direction parallel to the first face, the rectilinear electrically conducting lines of the second and third radiating elements being situated in a same plane as the rectilinear electrically conducting line of the first radiating element and inclined with respect to the electrically conducing line of the first radiating element, the radiating dipoles of the three radiating elements being substantially perpendicular to the plane which contains the rectilinear electrically conducting lines of the three radiating elements.