Crossed log-periodic dipole antenna and method of making same

Claim 1

In a crossed log-periodic dipole antenna construction having an axis, said construction having: first and second orthogonally displaced log-periodic antennas; each of said antennas having first and second half-dipole structures; each of said structures comprising an electrically conductive elongated boom having an outer surface and extending parallel to said axis, said structure also having a half-dipole assembly comprising half-dipole elements connected to and extending axially alternately from and perpendicular to opposite sides of said boom, the lengths of said elements of each assembly and the inter-element axial spacing thereof increasing from one end of the boom to the other in increments of a predetermined ratio, each half-dipole element of each of said assemblies being transversely aligned with a corresponding half-dipole element of the same size of the assembly of the other structures of the same antenna; and means for electrically feeding each of said booms, said booms being the feed lines for said half-dipole elements, the improvement comprising: each of said half-dipole assemblies constituting a unitary piece having a boom portion with said elements projecting therefrom, said boom portion having a thickness substantially less than that of the remainder of the assembly, said boom portion being electrically connected to and tightly engaging at least a portion of said outer surface of the adjacent boom.

Claim 12

The method of making a crossed log-periodic dipole antenna construction having an axis and having first and second orthogonally displaced log-periodic antennas, each of said antennas having first and second half-dipole structures, each of said structures having an elongated boom with an outer surface and extending parallel to said axis, said structure also having a half-dipole assembly comprising half-dipole elements connected to and extending axially alternatively from and perpendicular to opposite sides of said boom, the lengths of said elements of each assembly and the inter-element axial spacings thereof increasing from one end of the boom to the other in increments of a predetermined ratio, each half-dipole element of each of said assemblies being transversely aligned with a corresponding half-dipole element of the same size of the assembly of the other structure of the same antenna, and means for electrically feeding each of said booms for electrically energising said half-dipole elements, the method consisting of the steps of: forming each of said assemblies from a unitary planar piece of electrically conductive material and thereby making a central boom portion from which the associated half-dipoles project; pressing said boom portion of each assembly into a shape corresponding to that of the outer surface of the boom; and permanently bonding said boom portion of each structure to the adjacent boom.

Claim 13

The method of making a crossed log-periodic dipole antenna construction having an axis and having first and second orthogonally displaced log-periodic antennas, each of said antennas having first and second half-dipole structures, each of said structures having an elongated boom with an outer surface and extending parallel to said axis, said structure also having a half-dipole assembly comprising half-dipole elements connected to and extending axially alternatively from and perpendicular to opposite sides of said boom, the lengths of said elements of each assembly and the inter-element axial spacings thereof increasing from one end of the boom to the other in increments of a predetermined ratio, each half-dipole element of each of said assemblies being transversely aligned with a corresponding half-dipole element of the same size of the assembly of the other structure of the same antenna, and means for electrically feeding each of said booms for electrically energising said half-dipole elements, the method consisting of the steps of: forming each of said assemblies from a unitary planar piece of electrically conductive material and thereby making a central boom portion from which the associated half-dipoles project; pressing said boom portion of each assembly into a shape corresponding to that of the outer surface of the boom; and permanently bonding said boom portion of each structure to the adjacent boom.