Photo Source/Description

Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Array of four log-periodic dipole arrays used for tracking.

Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Array of four triangular tooth log-periodic antennas used for reflector feeds.

Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Details of infinite-balun feed for a planar log-spiral antenna.

Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna showing (left) spiral pattern etched on flat sheet of teflon-impregnated fiberglass and (right) after forming into conical shape and adding feed coax to one arm and dummy cable (to improve symmetry) to the other arm.

Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Vertically polarized log-periodic array for use at HF.

Planar log-spiral slot antenna Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Planar log-spiral slot antenna.

Vertically polarized log-periodic zigzag antenna Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Vertically polarized log-periodic zigzag antenna with horizontal phasing stubs, sometimes called the "bent LP zigzag".

University of Illinois radio telescope for extra-galactic sources Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: University of Illinois radio telescope used to map extra-galactic sources, a 400 x 600 foot cylindrical parabolic reflector made by covering a shaped-earth excavation with asphalt and wire screen. A catwalk at 155 feet above the ground supports about 400 conical log-spiral antennas along the focal line. Scanning in one plane was achieved by the earth's rotation; in the other plane by physically rotating the circularly polarized spirals. The log-spiral antennas were designed by Prof. J. D. Dyson, the feed system was designed by Prof. Y. T. Lo.

University of Illinois radio telescope Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: University of Illinois radio telescope.

Conical log-spiral antennas Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antennas

Array of two conical log-spiral antennas Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Array of two conical log-spiral antennas.

Log-periodic array of helical dipoles Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Log-periodic array of helical dipoles.

Array of four conical log-spiral antennas Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Array of four conical log-spiral antennas.

Early diagram of scaled cells of a general log-periodic structure Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Early diagram of scaled cells of a general log-periodic structure.

Four-arm conical log-spiral antenna #1 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Four-arm conical log-spiral antenna constructed from coaxial cable.

Four-arm conical log-spiral antenna #2 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Four-arm conical log-spiral antenna constructed from coaxial cable.

Early commercial version of a wire-outline log-periodic array Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Early commercial version of a wire-outline log-periodic triangular tooth array.

Horizontal array of two log-periodic dipole arrays Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Horizontal array of two log-periodic dipole arrays.

Two conical log-spiral antennas; (left) wide arm (right) cable arm Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Two conical log-spiral antennas; (left) wide arm (right) cable arm.

Small scale model of log-periodic resonant-V array Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Small scale model of log-periodic resonant-V array.

Conical log-spiral antenna Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna.

Small scale model of a log-periodic dipole array Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Small scale model of a log-periodic dipole array.

Loosely wrapped four-arm conical log-spiral antenna Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Loosely wrapped four-arm conical log-spiral antenna for producing hemispherical coverage.

Reflector feed Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Reflector feed.

Planar log-spiral slot antenna Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Planar log-spiral slot antenna.

Conical log-spiral antenna made from coaxial cable #1 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna made from coaxial cable.

Conical log-spiral antenna made from coaxial cable #2 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna made from coaxial cable.

Conical log-spiral antenna made from coaxial cable #3 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna made from coaxial cable.

Two-element array of conical log-spiral antennas Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Two-element array of conical log-spiral antennas.

Conical log-spiral for University of Illinois radio telescope #1 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral for University of Illinois radio telescope.

Conical log-spiral for University of Illinois radio telescope #2 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral for University of Illinois radio telescope.

Quad array of conical log-spiral antennas Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Quad array of conical log-spiral antennas.

End-on view of four-arm conical log-spiral antennas Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: End-on view of four-arm conical log-spiral antennas.

Two-element array of conical log-spiral antennas with radome Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Two-element array of conical log-spiral antennas with radome.

Conical log-spiral for University of Illinois radio telescope Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral for University of Illinois radio telescope.

Log-spiral antenna on an early navigation satellite S ource: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Log-spiral antenna on an early navigation satellite.

Small scale model of a log-periodic dipole array Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Small scale model of a log-periodic dipole array.

Conical log-spiral antenna Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna.

Commercial conical log-spiral antenna Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Commercial conical log-spiral antenna.

Conical log-spiral antenna #1 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna.

Conical log-spiral antenna #2 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna.

Conical log-spiral antenna #3 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna.

Conical log-spiral antenna #4 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna.

Conical log-spiral antenna #5 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna.

Conical log-spiral antenna #6 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Conical log-spiral antenna.

Four overlapping parabolic reflectors #1 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Four overlapping parabolic reflectors fed with log-periodic dipole arrays.

Four overlapping parabolic reflectors # 2 Source: Professor Paul Mayes, University of Illinois at Urbana-Champaign Description: Four overlapping parabolic reflectors fed with log-periodic dipole arrays.