Dual polarized antenna using shift series feed
The present disclosure provides a dual-polarized antenna, which is advantageous for a reduction in size by significantly reducing the complexity of a structure while satisfying a Cross Polarization ratio (CPR) characteristic and an isolation characteristic, that is, advantages of a dual feed, by enabling a dual feed using a shift series feed even without another structure in one antenna structure.
1. A dual-polarized antenna comprising:
a base substrate;
a feed unit supported on the base substrate and comprising a first feed substrate and a second feed substrate disposed to cross each other; and
a radiation plate supported on the feed unit,
wherein the first feed substrate comprises a first feed line configured to supply a first region with a first reference-phase signal in a first direction of the radiation plate and to supply a second region sequential to the first region with a first anti-phase signal having a phase opposite to a phase of the first reference-phase signal according to a shift feed method, and
the second feed substrate comprises a second feed line configured to supply a third region with a second reference-phase signal in a second direction of the radiation plate and to supply a fourth region sequential to the third region with a second anti-phase signal having a phase opposite to a phase of the second reference-phase signal according to the shift feed method,
wherein each of the first feed line and the second feed line is implemented so that sequential feeds having a predetermined time difference are performed in an identical direction on the radiation plate according to the shift feed method.
2. The dual-polarized antenna of claim 1 , wherein:
the first feed line comprises a first reference-phase coupling electrode extending in parallel to the first region and a first anti-phase coupling electrode extending in parallel to the second region in the first direction from one-side short side of the first feed substrate, and
the second feed line comprises a second reference-phase coupling electrode extending in parallel to the third region and a second anti-phase coupling electrode extending in parallel to the fourth region in the second direction from one-side short side of the second feed substrate.
3. The dual-polarized antenna of claim 2 , wherein:
the first feed line further comprises a first direct feed line having one end electrically connected to a signal line of the base substrate on one-side long side of the first feed line and having another end connected to one end of the first reference-phase coupling electrode, a first coupling feed line extending from one end of the first anti-phase coupling electrode toward a one-side long side of the first feed substrate, and a first transfer line connected from another end of the first reference-phase coupling electrode to one end of the first coupling feed line, and
the second feed line comprises a second direct feed line having one end electrically connected to the signal line of the base substrate on one-side long side of the second feed line and having another end connected to one end of the second reference-phase coupling electrode, a second coupling feed line extending from one end of the second anti-phase coupling electrode to a one-side long side of the second feed substrate, and a second transfer line connected from another end of the second reference-phase coupling electrode to one end of the second coupling feed line.
4. The dual-polarized antenna of claim 3 , wherein each of the first transfer line and the second transfer line has a shifted structure and path length so that an electric current having a phase difference of 180° compared to a reference-phase signal is applied to each coupling feed line.
5. The dual-polarized antenna of claim 4 , wherein the first coupling feed line and the second coupling feed line form an L-probe feed structure by performing a function as a feed line for supplying a corresponding anti-phase coupling electrode with an anti-phase signal applied through a corresponding transfer line.
6. The dual-polarized antenna of claim 1 , wherein:
a part of at least one of the first feed line and the second feed line is formed in one surface of the feed substrate, and
a remainder of the at least one of the first feed line and the second feed line is formed in another surface of the feed substrate.
7. The dual-polarized antenna of claim 6 , wherein in at least one of the first feed line and the second feed line, a portion corresponding to a reference-phase signal is formed in the one surface, and a portion corresponding to an anti-phase signal is formed in the another surface.
8. The dual-polarized antenna of claim 6 , wherein at least one of the first feed line and the second feed line is implemented so that an electric current fed through some feed lines formed in the one surface is coupled with remaining feed lines formed in the another surface.
9. The dual-polarized antenna of claim 1 , wherein:
the radiation plate is square, and
a circular hole for diverting a direction of a radiated current within the radiation plate is formed in the radiation plate.
10. The dual-polarized antenna of claim 9 , wherein:
a length of a diagonal line of the radiation plate is identical with a length of a half wavelength of a center frequency of a use frequency, and
a diameter of the hole is determined based on an area of the radiation plate.