JP-7855302-B2 - Antenna equipment

Inventors

• 深山 恭兵
• 岸本 知久

Assignees

• 日本アンテナ株式会社

Dates

Publication Date

20260508

Application Date

20220624

Claims (11)

1. An antenna device comprising a metal plate and a broadband antenna placed on the metal plate, The aforementioned broadband antenna is An insulating substrate which is a flat, rectangular plate, It consists of a first antenna element and a second antenna element formed of a conductive material in a planar shape and arranged side by side on one surface of the substrate. The first antenna element and the second antenna element are composed of a tapered portion that widens in a tapered shape and a rectangular portion that follows the tapered portion, with feed points formed at the ends of the tapered portions where the first antenna element and the second antenna element face each other, and the tapered portion is formed to widen in a tapered shape from each of the feed points. An antenna device characterized in that the metal plate is provided with slits at predetermined intervals, the feed point is located within the predetermined intervals of the slits so that the feed point does not face the metal plate, and the metal plate is arranged on the other side of the substrate in the broadband antenna.
2. The antenna device according to claim 1, characterized in that the insulating substrate in the broadband antenna is made of a transparent resin, and further, the first antenna element and the second antenna element are formed of a mesh-like conductor that is visually transparent and transmits visible light.
3. The antenna device according to claim 2, characterized in that the insulating substrate in the broadband antenna is a film substrate made of transparent resin.
4. The antenna device according to any one of claims 1 to 3, characterized in that, when the wavelength of the center frequency in the design frequency band of the antenna device is λ, the predetermined spacing of the slit portion provided in the metal plate is approximately λ/14.
5. An antenna device comprising a metal plate and a broadband antenna placed on the metal plate, The aforementioned broadband antenna is An insulating substrate which is a flat, rectangular plate, It consists of a first antenna element and a second antenna element formed of a conductive material in a planar shape and arranged side by side on one surface of the substrate. The first antenna element and the second antenna element are composed of a tapered portion that widens in a tapered shape and a rectangular portion that continues from the tapered portion, with feed points formed at the ends of the first antenna element and the second antenna element facing each other, and the tapered portion is formed to widen in a tapered shape from each of the feed points, and a projection is formed extending from the tapered portion. An antenna device characterized in that the metal plate is provided with slits at predetermined intervals, the feed point and the protrusion are located within the predetermined intervals of the slits so that the feed point and the protrusion do not face each other on the metal plate, and the metal plate is arranged on the other side of the substrate in the broadband antenna.
6. The antenna device according to claim 5, characterized in that the insulating substrate in the broadband antenna is made of a transparent resin, and furthermore, the first antenna element and the second antenna element on which the protrusions are formed are made of a mesh-like conductor that is visually transparent and transmits visible light, and the feed points of the first antenna element and the second antenna element are formed in a solid shape.
7. The antenna device according to claim 6, characterized in that the insulating substrate in the broadband antenna is a film substrate made of transparent resin.
8. The antenna device according to claim 5, characterized in that the insulating substrate in the broadband antenna is made of a transparent resin substrate, and furthermore, the first antenna element and the second antenna element on which the protrusions are formed are made of a mesh-like conductor consisting of triangular, square, polygonal, circular, or elliptical meshes that are visually transparent and transmit visible light, and the feed points of the first antenna element and the second antenna element are formed in a solid form.
9. The antenna device according to claim 8, characterized in that the insulating substrate in the broadband antenna is a film substrate made of transparent resin.
10. The antenna device according to any one of claims 5 to 9, characterized in that the length of the protrusions formed on the first antenna element and the second antenna element in the broadband antenna is approximately 0.036λa to approximately 0.059λa with respect to the wavelength λa at a frequency of 0.9 GHz in the design frequency band, and approximately 0.080λb to approximately 0.130λb with respect to the wavelength λb at a frequency of 2.0 GHz.
11. The antenna device according to any one of claims 5 to 9, characterized in that, when the wavelength of the center frequency in the design frequency band of the broadband antenna is λ, the predetermined spacing of the slit portions provided in the metal plate is approximately λ/14.

Description

This invention relates to an antenna device that can reduce the degradation of antenna performance even when used in close proximity to a metal body. With the expansion of the IoT (Internet of Things) market, the range of frequencies used is also expanding, leading to increased demand for broadband antennas. Furthermore, due to limited installation space, antennas for communication modules are sometimes used in close proximity to metal objects, which are not ideal in terms of radio wave conditions. In such cases, the metal object can affect the inductive and capacitive components of the antenna, changing its impedance and potentially significantly degrading its performance. Therefore, there is a need for broadband antennas that can minimize performance degradation even when used in close proximity to metal objects. Patent No. 5138190 This is a front view showing the configuration of an antenna device according to the first embodiment of the present invention.This is a rear view showing the configuration of the antenna device according to the first embodiment of the present invention.This is a top view showing the configuration of an antenna device according to the first embodiment of the present invention.These are a left side view and a right side view showing the configuration of the antenna device according to the first embodiment of the present invention.This is a front view showing the dimensions of the antenna device according to the first embodiment of the present invention.This is a front view showing a modified configuration of the antenna device according to the first embodiment of the present invention.This is a front view showing the configuration of an antenna device according to a second embodiment of the present invention.This is a rear view showing the configuration of an antenna device according to a second embodiment of the present invention.This is a top view showing the configuration of an antenna device according to a second embodiment of the present invention.These are a left side view and a right side view showing the configuration of an antenna device according to a second embodiment of the present invention.This is a front view showing the dimensions of the antenna device according to the second embodiment of the present invention.This is a front view showing the configuration of an antenna device according to a third embodiment of the present invention.This is a rear view showing the configuration of an antenna device according to a third embodiment of the present invention.This is a top view showing the configuration of an antenna device according to a third embodiment of the present invention.These are a left side view and a right side view showing the configuration of an antenna device according to a third embodiment of the present invention.This is a front view showing the configuration of an antenna device according to a fourth embodiment of the present invention.This is a rear view showing the configuration of an antenna device according to the fourth embodiment of the present invention.This is a top view showing the configuration of an antenna device according to a fourth embodiment of the present invention.These are a left side view and a right side view showing the configuration of an antenna device according to a fourth embodiment of the present invention.This graph shows the bandwidth of VSWR 2.0 or less with respect to the length of the protrusion of the antenna element in the planar antenna of the second embodiment of the present invention.This table shows the wavelength ratio of the length of the projection of the antenna element to the wavelength of a predetermined design frequency in a planar antenna in the antenna device of the second embodiment according to the present invention.This graph shows the bandwidth with a VSWR of 3.0 or less as a function of the slit spacing in the antenna device of the first embodiment according to the present invention.This table shows the wavelength ratio of the slit spacing to the wavelength of a predetermined design frequency in the antenna device of the first embodiment according to the present invention.This graph shows the bandwidth with a VSWR of 3.0 or less as a function of the slit spacing in the antenna device of the second embodiment according to the present invention.This table shows the wavelength ratio of the slit spacing to the wavelength of a predetermined design frequency in the antenna device of the second embodiment according to the present invention.This is a front view showing the configuration of a conventional planar antenna.This is a rear view showing the configuration of a conventional planar antenna. <Antenna device according to the first embodiment of the present invention> Figures 1 to 4 show the configuration of the antenna device 1 according to the first embodiment of the present invention. Figure 1 is a front view showing the configuration of the antenna device 1 of the first embodiment, Figure 2 is a re