Superluminal antenna
View Patent ↗A superluminal antenna element integrates a balun element to better impedance match an input cable or waveguide to a dielectric radiator element, thus preventing stray reflections and consequent undesirable radiation. For example, a dielectric housing material can be used that has a cutout area. A cable can extend into the cutout area. A triangular conductor can function as an impedance transition. An additional cylindrical element functions as a sleeve balun to better impedance match the radiator element to the cable.
1. A superluminal antenna element, comprising:
a dielectric housing having a cutout, the cutout having a first plurality of steps and a second plurality of steps, the first and second pluralities of steps arranged in opposing pairs;
a first conductive element substantially covering the first plurality of steps;
a second conductive element substantially covering the second plurality of steps;
a dielectric radiator element mounted within the cutout area, the radiator element having first and second spaced ends mounted in an opposing pair of steps;
a conductive impedance transition electrically connected to the first conductive element;
and sleeve balun depending from and electrically connected to the second conductive element; whereby imposing a time-varying signal on the first and second conductive elements induces a polarization current in the dielectric radiator element.
2. The superluminal antenna element of claim 1 , further comprising first and second coaxial conductors with a conducting cylinder connected to them in such a way to form a sleeve or bazooka balun.
3. The superluminal antenna element of claim 1 , wherein the cutout area is plated with conductive material to form the first and second conductive elements.
4. The superluminal antenna element of claim 1 , further including a conductive block positioned within the cutout area and having a hole therein through which a cable passes.
5. The superluminal antenna element of claim 1 , further including a conductive impedance matching element coupled between the radiator element and the feed conductor.
6. The superluminal antenna element of claim 5 , wherein the conductive impedance matching element gradually changes the impedance from the impedance at the feed conductor to the impedance at the radiator element.
7. The superluminal antenna of claim 1 , wherein the dielectric material includes a glass epoxy laminate.
8. The superluminal antenna of claim 1 , wherein the radiator element is formed from a low-loss-tangent dielectric.
9. The superluminal antenna of claim 1 , further comprising a coaxial cable including first and second conductors coupled to the first conductive element and the second conductive element respectively, wherein the first conductor and the second conductor share a same geometric axis.
10. The superluminal antenna of claim 1 , wherein the dielectric housing is rectangular or wedge shaped.
11. The antenna element of claim 1 , wherein the radiating element is mounted within an outermost pair of opposing steps.