Periodic antenna adapted for handling high power

Claim 2

A periodic antenna particularly adapted for handling high power comprising at least three resonant radiating elements, a common feed line for said elements, said feed line comprising a hollow electrically conducting, metallic sleeve extending along substantially the entire length of the line, adjacent ones of said elements being spaced along said feed line by a distance substantially less than a quarter wavelength of the operating frequency of the elements, means for providing substantially 180* phase shift between adjacent ones of the elements, each of said phase shift means including a shunt distributed parameter slow-wave delay line connected between adjacent ones of said elements and located inside of the sleeve, said line including a conductor having distributed inductance for heat distribution over its entire length and distributed capacitance as a dielectric between the conductor and sleeve, each of said shunt lines being spaced longitudinally in the sleeve from the adjacent line and tuned so it has a length substantially equal to an integral multiple of a quarter wavelength of the resonant frequency of a radiating element adjacent thereto.

Claim 3

The periodic antenna of claim 1 wherein each of the shunt lines includes a helical coil coaxial with the sleeve and having a length substantially equal to a quarter wavelength.

Claim 4

The periodic antenna of claim 2 wherein the shunt line further includes a tuning capacitor for precisely determining the resonant frequency of the shunt line.

Claim 5

The periodic antenna of claim 3 wherein the capacitor includes first and second electrodes respectively formed by the hollow, electrically conducting sleeve and an electrically conducting tube coaxial with the conducting sleeve, and an annular, solid dielectric cylinder positioned between said electrodes.

Claim 6

A periodic antenna particularly adapted for handling high power comprising a ground plane, a feed line positioned above the ground plane, at least three monopole resonant radiating elements spaced along the ground plane conductor and positioned to extend from the feed line in a direction away from the ground plane, said feed line and elements being positioneD above the ground plane so that there is a radiation image of each radiating element in the ground plane, said feed line comprising a hollow, electrically conducting, metallic sleeve extending along substantially the entire length of the line, adjacent ones of said elements being spaced along said feed line by a distance substantially less than a quarter wavelength of the operating frequency of the elements, means for providing substantially 180* phase shift between adjacent ones of the elements, each of said phase shift means including a shunt distributed parameter slow-wave delay line connected between adjacent ones of said elements and located inside of the sleeve, said line including a conductor having distributed inductance for heat distribution over its entire length and distributed capacitance as a dielectric between the conductor and sleeve, each of said shunt lines being spaced longitudinally in the sleeve from the adjacent line and tuned so it has a length substantially equal to an integral multiple of a quarter wavelength of the resonant frequency of a radiating element adjacent thereto.

Claim 7

A periodic antenna particularly adapted for handling high power comprising a ground plane, a feed line positioned above the ground plane, at least three monopole resonant radiating elements spaced along the ground plane conductor and positioned to extend from the feed line in a direction away from the ground plane, said feed line and elements being positioneD above the ground plane so that there is a radiation image of each radiating element in the ground plane, said feed line comprising a hollow, electrically conducting, metallic sleeve extending along substantially the entire length of the line, adjacent ones of said elements being spaced along said feed line by a distance substantially less than a quarter wavelength of the operating frequency of the elements, means for providing substantially 180* phase shift between adjacent ones of the elements, each of said phase shift means including a shunt distributed parameter slow-wave delay line connected between adjacent ones of said elements and located inside of the sleeve, said line including a conductor having distributed inductance for heat distribution over its entire length and distributed capacitance as a dielectric between the conductor and sleeve, each of said shunt lines being spaced longitudinally in the sleeve from the adjacent line and tuned so it has a length substantially equal to an integral multiple of a quarter wavelength of the resonant frequency of a radiating element adjacent thereto.

Claim 8

The periodic antenna of claim 5 wherein the ground plane includes a metallic threshold strip, and the shunt line includes first and second terminals of the conductor respectively connected to the feed line and the ground plane conductor, said second terminal being connected by a d.c. connection to the threshold strip between the resonant elements for which the delay line is tuned.

Claim 9

The periodic antenna of claim 6 wherein each of the shunt lines includes a helical coil coaxial with the sleeve and having a length substantially equal to a quarter wavelength.

Claim 10

The periodic antenna of claim 7 wherein the shunt line further includes a tuning capacitor for precisely determining the length of the shunt line.

Claim 11

The periodic antenna of claim 8 wherein the capacitor includes first and second electrodes respectively formed by the hollow, electrically conducting sleeve and an electrically conducting tube coaxial with the conducting sleeve, and an annular, solid dielectric cylinder positioned between said electrodes.

Claim 12

The periodic antenna of claim 5 wherein the lengths of said elements differ from each other and the spacing relative to a common apex point between adjacent ones of said elements differs in accordance with the log periodic criteria, said ground plane includes a metallic threshold strip, said shunt line including first and second terminals of the conductor respectively connected to the feed line and the ground plane conductor, said second terminal being connected by a d.c. connection to the threshold strip between the resonant elements for which the delay line is tuned at a point spaced from the apex by substantially the geometric mean of the distance from the apex of the adjacent elements to which the shunt line is tuned.