Multi-band base station antenna having improved isolation characteristics
A multi-band base station antenna comprises: a reflector; a plurality of high-band radiators arranged on the reflector; and a plurality of low-band radiators arranged on the reflector. Each of the plurality of low-band radiators comprises: a radiation substrate; a first dipole radiator including a first+dipole arm and a first−dipole arm formed on the radiation substrate; a second dipole radiator including a second+dipole arm and a second−dipole arm formed on the radiation substrate; and a metal coupler coupled to the lower portion of the radiation substrate. The metal coupler comprises: a first coupling patch located below the first+dipole arm; a second coupling patch located below the first−dipole arm; a third coupling patch located below the second+dipole arm; and a fourth coupling patch located below the second−dipole arm.
1. A multi-band base station antenna, comprising:
a reflector;
a plurality of high-band radiators arranged on the reflector; and
a plurality of low-band radiators arranged on the reflector,
wherein each of the plurality of low-band radiators comprises:
a radiation substrate;
a first dipole radiator including a first+dipole arm and a first−dipole arm formed on the radiation substrate;
a second dipole radiator including a second+dipole arm and a second−dipole arm formed on the radiation substrate; and
a metal coupler coupled to a lower portion of the radiation substrate, and
wherein the metal coupler comprises: a first coupling patch located below the first+dipole arm; a second coupling patch located below the first−dipole arm; a third coupling patch located below the second+dipole arm; a fourth coupling patch located below the second−dipole arm; a ring-shaped patch portion with a slot formed in the center; and first to fourth supporters vertically protruding from the ring-shaped patch portion, and
wherein each of the first to fourth coupling patches is coupled to the first to fourth supporters, respectively.
2. The multi-band base station antenna according to claim 1 ,
wherein the low-band radiators further comprise a balun unit that performs impedance matching and provides a feed signal,
wherein the balun unit passes through the slot and is coupled to the radiation substrate.
3. The multi-band base station antenna according to claim 1 ,
wherein the low-band radiators further comprise:
a first+coupling arm formed on the lower portion of the radiation substrate and formed at a position where electromagnetic coupling is possible with the first+dipole arm;
a first−coupling arm formed on the lower portion of the radiation substrate and formed at a position where electromagnetic coupling with the first−dipole arm is possible;
a second+coupling arm formed on the lower portion of the radiation substrate and formed at a position where electromagnetic coupling with the second+dipole arm is possible; and
a second−coupling arm formed on the lower portion of the radiation substrate and formed at a position where electromagnetic coupling with the second−dipole arm is possible.
4. The multi-band base station antenna according to claim 3 ,
wherein the first+coupling arm, the first−coupling arm, the second+coupling arm and the second−coupling arm extend in a direction rotated by a predetermined angle compared to an extension direction of each of the first+dipole arm, the first−dipole arm, the second+dipole arm and the second−dipole arm.
5. The multi-band base station antenna according to claim 4 ,
wherein the rotated direction is a direction away from the high-band radiators.
6. The multi-band base station antenna according to claim 3 ,
wherein, on an upper portion of the radiation substrate, a plurality of auxiliary arms are formed between the first dipole radiator and the second dipole radiator.
7. The multi-band base station antenna according to claim 6 ,
wherein, on the lower portion of the radiation substrate, a plurality of coupling auxiliary arms are formed at positions where electromagnetic coupling with each of the plurality of auxiliary arms is possible.
8. A multi-band base station antenna, comprising:
a reflector;
a plurality of high-band radiators arranged on the reflector; and
a plurality of low-band radiators arranged on the reflector,
wherein each of the plurality of low-band radiators comprises:
a radiation substrate;
a first dipole radiator including a first+dipole arm and a first−dipole arm formed on the radiation substrate;
a second dipole radiator including a second+dipole arm and a second−dipole arm formed on the radiation substrate;
a first+coupling arm formed on a lower portion of the radiation substrate and formed at a position where electromagnetic coupling is possible with the first+dipole arm;
a first−coupling arm formed on the lower portion of the radiation substrate and formed at a position where electromagnetic coupling with the first−dipole arm is possible;
a second+coupling arm formed on the lower portion of the radiation substrate and formed at a position where electromagnetic coupling with the second+dipole arm is possible; and
a second−coupling arm formed on the lower portion of the radiation substrate and formed at a position where electromagnetic coupling with the second−dipole arm is possible; and
wherein the first+coupling arm, the first−coupling arm, the second+coupling arm and the second−coupling arm extend in a direction rotated by a predetermined angle compared to an extension direction of each of the first+dipole arm, the first−dipole arm, the second+dipole arm and the second−dipole arm;
wherein each of the plurality of low-band radiators comprise a metal coupler coupled to the lower portion of the radiation substrate, and
wherein the metal coupler comprises: a first coupling patch located below the first+dipole arm; a second coupling patch located below the first−dipole arm; a third coupling patch located below the second+dipole arm; and a fourth coupling patch located below the second−dipole arm.
9. The multi-band base station antenna according to claim 8 ,
wherein the metal coupler further comprises:
a ring-shaped patch portion with a slot formed in the center; and
first to fourth supporters vertically protruding from the ring-shaped patch portion,
wherein each of the first to fourth coupling patches is coupled to the first to fourth supporters, respectively.
10. The multi-band base station antenna according to claim 9 ,
wherein the low-band radiators further comprise a balun unit that performs impedance matching and provides a feed signal,
wherein the balun unit passes through the slot and is coupled to the radiation substrate.
11. The multi-band base station antenna according to claim 8 ,
wherein the rotated direction is a direction away from the high-band radiators.
12. The multi-band base station antenna according to claim 8 ,
wherein, on an upper portion of the radiation substrate, a plurality of auxiliary arms are formed between the first dipole radiator and the second dipole radiator.
13. The multi-band base station antenna according to claim 12 ,
wherein, on the lower portion of the radiation substrate, a plurality of coupling auxiliary arms are formed at positions where electromagnetic coupling with each of the plurality of auxiliary arms is possible.