The invention discloses a planar
helical antenna of a combined structure. A planar equiangular
helical antenna is combined with a planar
Archimedes screw antenna. One and half ring of equiangular
helix structure is used in the inner ring, an Archimedes
helix structure is used in the outer ring, and the
tail end of equiangular
helix is in seamless connection with the initial end of Archimedes helix. The planar
helical antenna of the combined structure is a groove-
radiation planar helix antenna with double symmetrical arms, the
diameter of the antenna is 50mm, the thickness of an antenna base plate is 0.8mm, and a
dielectric slab of a
dielectric constant of 2.2 is used. The planar
helical antenna also comprises four surface-mounted resistors, wherein the resistance of the
resistor is 160
ohm, the resistors are connected between the outermost ring and the last but one ring of the antenna, and the angle between the adjacent surface-mounted resistors is 90degree; and the antenna further comprises two
copper rings arranged in the periphery of the antenna. According to the invention, the size of the planar
helical antenna is effectively reduced, and the
circular polarization performance of the antenna is improved.