CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 10-2019-0168026, filed with the Korean Intellectual Property Office on Dec. 16, 2019, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to an array antenna, more particularly to a millimeter wave band array antenna.

2. Description of the Related Art

To satisfy demands for increased transmission speeds in 5G networks, the 3GPP adopted millimeter wave technology. This is because the millimeter wave band can provide a higher bandwidth than the existing 3 GHz band. However, although the millimeter wave band offers the advantage of high transmission capacity, one of its properties is that the state of the channel may vary drastically depending on the environment. A millimeter wave link may show a high transmission rate in a LOS (line-of-sight) environment, but in a NLOS (non-LOS) environment, the SINR can drop by up to 35 dB. This is because millimeter wave signals are vulnerable to obstacles such as buildings, trees, people, etc., and show very high attenuation properties.

Due to these reasons, the millimeter wave band antenna emits signals in a very narrow beam width to improve gains, resulting in an increase in the shadow area. Also, since the millimeter wave band antenna has a high frequency, there is the problem that the delay spread may be increased in a multipath propagation environment.

SUMMARY OF THE INVENTION

An aspect of the invention provides a millimeter wave band antenna capable of minimizing the occurrence of shadow areas and preventing the delay spread caused by multiple paths.

To achieve the objective above, one aspect of the invention provides a millimeter wave array antenna that includes: a first dipole array antenna unit including a multiple number of first +dipole members, which are formed on an upper portion of a first substrate and configured to be provided with feed signals through a first feed line, and a multiple number of first −dipole members, which are formed on a lower portion of the first substrate and joined with a ground plane formed on a lower portion of the first substrate; and a slot antenna unit including a multiple number of slot radiators, which are formed on an upper portion of the first substrate, a third feed line, which is formed on a lower portion of the first substrate and configured to provide feed signals to the plurality of slot radiators, and a fourth feed line, which is formed on an upper portion of a second substrate that is stacked onto an upper portion of the first substrate and which is configured to provide feed signals to the slot radiators, where the ground plane includes a first sloped structure, which has an upward slope of a first angle toward a rightward direction from a point of junction with a first −dipole member, and a second sloped structure, which has an upward slope of the first angle toward a leftward direction from the point of junction.

The first sloped structure and the second sloped structure may be formed for every point of junction between the multiple first −dipole members and the ground plane.

The array antenna may further include a second dipole array antenna unit that includes a multiple number of second +dipole members, which are formed on an upper portion of the first substrate and configured to be provided with feed signals through a second feed line, and a multiple number of second −dipole members, which are formed on a lower portion of the first substrate and joined with the ground plane formed on a lower portion of the first substrate.

The array direction of the first dipole array antenna unit and the array direction of the second dipole array antenna unit may be orthogonal to each other.

The first +dipole members, the first −dipole members, the second +dipole members, and the second −dipole members may be bent to an angle of 90 degrees or smaller.

The third feed line and the fourth feed line may provide feed signals having a phase difference of 90 degrees, so that the slot radiators may emit circularly polarized signals.

Any one of the first dipole array antenna unit, the second dipole array antenna unit, and the slot antenna unit may be selected and receive feed signals.

Another aspect of the invention provides a millimeter wave array antenna that includes: a first dipole array antenna unit including a multiple number of first +dipole members, which are formed on an upper portion of a first substrate and configured to be provided with feed signals through a first feed line, and a multiple number of first −dipole members, which are formed on a lower portion of the first substrate and joined with a ground plane formed on a lower portion of the first substrate; a second dipole array antenna unit including a multiple number of second +dipole members, which are formed on an upper portion of the first substrate and configured to be provided with feed signals through a second feed line, and a multiple number of second −dipole members, which are formed on a lower portion of the first substrate and joined with the ground plane formed on a lower portion of the first substrate; and a slot antenna unit including a multiple number of slot radiators, which are formed on an upper portion of the first substrate, a third feed line, which is formed on a lower portion of the first substrate and configured to provide feed signals to the multiple slot radiators, and a fourth feed line, which is formed on an upper portion of a second substrate that is stacked onto an upper portion of the first substrate and which is configured to provide feed signals to the multiple slot radiators, where the array direction of the first dipole array antenna unit and the array direction of the second dipole array antenna unit are different.

A millimeter wave array antenna according to certain embodiments of the invention can provides the advantages of minimizing the occurrence of shadow areas and preventing the delay spread caused by multiple paths.

Additional aspects and advantages of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

