Patent Grant
10727585
This application claims priority to and the benefit of Korean Patent Application No. 10-2017-0087772 filed in the Korean Intellectual Property Office on Jul. 11, 2017, the entire contents of which are incorporated herein by reference.
The present invention relates to a directional monopole array antenna using a hybrid type ground plane, and more particularly, to a directional monopole array antenna using a hybrid type ground plane, which uses a ground plane designed with a PMC (perfect magnetic conductor) and a PEC (perfect electric conductor) to increase a beam width of an active element pattern, to maintain a reflection coefficient, and to have directionality.
A microstrip patch array antenna, which is one of planar antennas, is manufactured by using a printed board, and thus it is suitable for mass production, has a simple manufacturing process, has a low height, and is flat and robust. Therefore, although it is widely used as an array antenna device requiring a large number of small antennas, there is a disadvantage in that the gain is insufficient.
When the microstrip patch array antenna is designed by using an array structure to perform beam steering, a steering angle at a 3 dB bandwidth is limited to a maximum of 50°. Accordingly, various structures have been proposed to expand the steering angle. Therefore, a beam width of an active element pattern (AEP) is increased by reducing mutual coupling or using a meta-structured antenna, but a complexity of the design is increased.
A 5G mobile communication antenna and military radar require an array antenna capable of steering the beam width. However, a conventional array antenna has a disadvantage in that when the antenna is steered at 50° or more, the gain of the antenna is remarkably reduced, so that a high output is required and the power consumption is also increased
The technique of the present invention is disclosed in Korean Patent Laid-Open Publication No. 10-2008-0038061 (published on May 2, 2008).
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
The present invention has been made in an effort to provide a directional monopole array antenna using a hybrid type ground plane, which uses a ground plane designed with a PMC and a PEC to increase a beam width of an active element pattern, to maintain a reflection coefficient, and to have directionality.
An exemplary embodiment of the present invention provides a directional monopole array antenna using a hybrid type ground plane in which a plurality of monopole antennas are connected in a form of an array, wherein each of the monopole antennas includes: a ground plane designed to be divided into a PMC and a PEC such that a surface current induced in the PEC flows in a direction; and an antenna device vertically disposed in the ground plane.
In this case, the ground plane may be designed to have a size that is equal to or smaller than one wavelength of an antenna signal.
The PMC may be designed in a half area of the ground plane, and a dielectric pattern capable of phase adjustment may be inserted at predetermined intervals to serve as a reflector.
The PMC may be designed to have at least one of a corrugated soft surface structure, a mushroom structure, a hilbert curve structure, and a peano curve structure.
The monopoles may be formed to have a folded or spiral structure.
The PMC may serve to block a leakage current.
The monopole antennas may have a reflection coefficient of 20% or more at a bandwidth of −10 dB and a steering angle of more than 70° at a 3 dB bandwidth.
As such, according to the exemplary embodiment of the present invention, it is possible to design the directional monopole antenna using the hybrid type ground plane by dividing the ground plane of the monopole antenna having a simple structure into PMC and PEC areas such that the beam width of the active element pattern can be increased, the reflection coefficient can be maintained, and the direction of the surface current induced in the ground plane can be controlled, to thereby obtain the directionality.
In addition, according to the exemplary embodiment of the present invention, the gain of the antenna can be increased by designing a monopole antenna capable of steering the optical beam-width with a steering angle of 70° or more in the 3 dB bandwidth at an RF front end thereof.
Exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The thicknesses of lines and the sizes of the components illustrated in the drawings may be exaggerated for the clarity and convenience of description.
Further, the terminologies described below are terminologies determined in consideration of the functions in the present invention and may be construed in different ways by the intention of users and operators or the custom. Therefore, the definitions of the terminologies should be construed on the basis of the contents throughout this specification.
First, as shown in
In addition, when the half of the ground plane of
Finally, as shown in
An input impedance of the monopole antenna is a ratio of a flowing current to an applied voltage, and thus an input impedance graph (PMC-PEC monopole) of the monopole antenna in which the ground is designed by using the PMC and the PEC is almost the same as
Hereinafter, a directional monopole array antenna using a hybrid type ground plane according to an exemplary embodiment of the present invention will be described with reference to
As shown in
First, the ground plane 110 is separately designed by using the PMC and the PEC, and thus a surface current induced in the PEC flows in a direction as shown in
Specifically, as shown in
Accordingly, when the dielectric material pattern is inserted into a corrugated soft surface structure as shown in
The PMC may be designed to have at least one of a corrugated soft surface structure, a mushroom structure, a hilbert curve structure, and a peano curve structure. In addition, the PMC may be designed to have various structures.
The antenna device 120 is constituted by a conductor, and is vertically disposed in the ground plane 110 to perform functions of the monopole antenna 100.
According to the present exemplary embodiment, the monopole antenna 100 may be formed to have a folded or spiral structure.
When a size (area) of the entire ground plane 110 is smaller than the wavelength (1λ) of an antenna signal, a surface current as illustrated in
As illustrated in
Hereinafter, a performance of the directional monopole array antenna using the hybrid type ground plane according to an exemplary embodiment of the present invention will be described with reference to
As described above, since the input impedances of the monopole antenna to which the hybrid type ground plane 110 is not applied and the monopole antenna to which the hybrid type ground plane 110 is applied are almost the same, it is seen that reflection coefficients are measured to be the same.
As a result, the monopole antenna 100 according to the exemplary embodiment of the present invention has a broad band compared to a patch array antenna having a conventional directional radiation pattern since it has a reflection coefficient of 20% or more at a bandwidth of −10 dB and a steering angle of more than 70° at a 3 dB bandwidth.
As illustrated in
In addition, the beam width of the active element pattern can be expanded by connecting a plurality of monopole antennas 100 in a form of an array in consideration of mutual coupling between the antennas so as to enable light beam steering.
Specifically,
As illustrated in
As described above, according to the exemplary embodiment of the present invention, it is possible to design the directional monopole antenna using the hybrid type ground plane by dividing the ground plane of the monopole antenna having a simple structure into PMC and PEC areas such that the beam width of the active element pattern can be increased, the reflection coefficient can be maintained, and the direction of the surface current induced in the ground plane can be controlled, to thereby obtain the directionality.
In addition, according to the exemplary embodiment of the present invention, the gain of the antenna can be increased by designing a monopole antenna capable of steering the optical beam-width with a steering angle of 70° or more in the 3 dB bandwidth at an RF front end thereof.
While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2017-0087772 | Jul 2017 | KR | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 7034761 | Chiang et al. | Apr 2006 | B2 |
| 8018375 | Alexopoulos | Sep 2011 | B1 |
| 8188928 | Lin | May 2012 | B2 |
| 9281564 | Vincent | Mar 2016 | B2 |
| 20050195124 | Puente Baliarda | Sep 2005 | A1 |
| 20080316134 | Sato | Dec 2008 | A1 |
| 20090295662 | Suetsuna | Dec 2009 | A1 |
| 20100201584 | Schaffner | Aug 2010 | A1 |
| 20110057851 | Chung | Mar 2011 | A1 |
| 20140049437 | Hung | Feb 2014 | A1 |
| 20150029062 | Ng | Jan 2015 | A1 |
| 20150130673 | Ng | May 2015 | A1 |
| Number | Date | Country |
|---|---|---|
| 1 324 423 | Jul 2003 | EP |
| 10-2004-0006157 | Jan 2004 | KR |
| 10-2008-0038061 | May 2008 | KR |
| 10-2010-0059076 | Jun 2010 | KR |
| Number | Date | Country | |
|---|---|---|---|
| 20190020108 A1 | Jan 2019 | US |
