Polarized planar log periodic antenna

A circularly polarized planar antenna, comprising:

• four radiating conductor assemblies of a relatively flat geometry;
• a relatively flat base of dielectric material, with said base including a center position;
• each of said assemblies being attached to said base and being evenly angularly spaced about and facing said base center position;
• each of said radiating assemblies further comprising:
• an elongated conductive strip having first and second ends to form a stem, said stem having a width dimension at said second end greater than the width dimension at said first end and wherein said width dimension of said stem progressively increases from said first end to said second end as a function of the distance from said first end;
• a plurality of conductive strips forming branches to said stem, and said branches being spaced from one another with said plurality being divided into first and second portions, said first portion of said branches being integrally attached to and extending from the right side of said stem and said second portion of said branches being integrally attached to and extending from the left side of said stem;
• each said branch being of the form of a circular arc;
• and
• each said branch having a length dimension and wherein the length dimension of said branches progressively increases in length from branch to branch as a function of the radial distance of the respective branch from said first end of said stem;
• and with each of said four assemblies being angularly positioned 90 degrees apart about said center position of said dielectric base with the first end of said stems in said assemblies spaced a predetermined distance from and facing said center position to prevent direct electrical contact between said stems and with said branches of adjacent ones of said assemblies being interleaved without direct contact between said assemblies.

An antenna combination, comprising in combination:

• a first pair of relatively flat planar linear polarized log periodic antennas each of the kind including a central stem having first and second ends and a plurality of metal radiating elements spaced apart along and branching outwardly from said stem, with each of said radiating elements having the geometry of a circular arc;
• said pair of antennas being attached along a common axis to a single relatively planar dielectric base and being oriented in opposed relationship with said first ends of said central stems thereof spaced from and in confronting relationship with one another;
• a second pair of relatively flat planar linear polarized log periodic antennas each of the kind including a central stem having first and second ends and a plurality of metal radiating elements spaced apart along and branching outwardly from said stem, with each of said radiating elements having the geometry of a circular arc;
• said second pair of antennas being attached along a common axis to said relatively planar dielectric base and being oriented in opposed relationship with said first ends of said central stems thereof spaced from and in confronting relationship with one another;
• said first and second pairs of antennas being of substantially identical shape and geometry;
• said common axis of said first antenna pair and said common axis of said second antenna pair intersecting and bisecting one another and forming an angle therebetween of ninety degrees;
• and
• said radiating elements of said first pair of antennas being interleaved with the corresponding adjacent radiating elements of the second pair of antennas without direct electrical contact between said radiating elements of any one of said antennas with the radiating elements and central stem of any other one of said antennas.

An antenna, comprising in combination:

• a first pair of relatively flat planar linear polarized log periodic antennas each of the kind including a central stem and a plurality of metal radiating elements branching from said stem, each of said radiating elements having the geometry of a circular arc;
• said pair of antennas being attached along a common axis to a single relatively planar dielectric base and being oriented in opposed relationship with the ends of the central stems spaced from one another;
• a second pair of relatively flat planar linear polarized log periodic antennas each of the kind including a central stem and a plurality of metal radiating elements branching from said stem, each of said radiating elements having the geometry of a circular arc;
• said pair of antennas being attached along a common axis to said single relatively planar dielectric base and being oriented in opposed relationship with the ends of the central stems spaced from one another;
• said antennas being of substantially identical shape and geometry;
• said common axis of said first antenna pair and said common axis of said second antenna pair intersecting one another and forming an angle therebetween of ninety degrees to form a symmetrical arrangement about either of said two axes;
• said radiating elements of said first pair of antennas being interleaved with the corresponding adjacent radiating elements of the second pair of antennas without direct electrical contact between the radiating elements of any one pair of antennas with the radiating elements and central stem of the other pair of antennas;
• first and second coaxial transmission lines, each of said transmission lines containing a cylindrical outer conductor, a center conductor and insulating material therebetween;
• said center conductor of each transmission line extending a predetermined length beyond the end of said center conductor, said predetermined length being at least as great as the distance between the opposed ends of said antennas in either of said antenna pairs;
• said first transmission line being routed along a stem of one antenna of said first antenna pair with the outer conductor thereof in contact therewith and with said extending length of center conductor extending into contact with the stem of the second antenna in said first antenna pair;
• and
• said second transmission line being routed along a stem of one antenna of said second antenna pair with the outer conductor thereof in contact therewith and with said extending length of center conductor extending into contact with the stem of the second antenna in said second antenna pair.