JP-7854917-B2 - Antenna equipment

Inventors

• 小島 優

Assignees

• パナソニック株式会社

Dates

Publication Date

20260507

Application Date

20221026

Claims (11)

1. A directional antenna device used in connection with a power supply unit, A radiator comprising a plate-shaped first antenna element having a width in a first direction and extending in a second direction perpendicular to the first direction, and a second antenna element arranged on the same plane as the first antenna element, having a smaller width than the first antenna element and having one side connected to one side of the first antenna element via the power supply section, The device comprises a reflector that is arranged in a plane opposite to the radiator, has a width in the first direction and extends in the second direction, is plate-shaped, and is unpowered, The reflector has a first notch formed on the first side of the reflector that extends in the second direction, having a first opening. The reflector has a longer length than the radiator, The second antenna element has a length shorter than 1/4 of the wavelength of the operating frequency. The radiator and the reflector are spaced apart so that they can be electromagnetically coupled. The resistive component of the input impedance of the antenna device is adjusted by the length of the first antenna element. The reactance component of the input impedance of the antenna device is adjusted by the length of the second antenna element . The first notch is formed in a position that overlaps with at least one of the first antenna element and the second antenna element when the antenna device is viewed in plan. Antenna device.
2. The first notch is formed in a position that overlaps only with the second antenna element of the first antenna element when the antenna device is viewed in plan. The antenna device according to claim 1.
3. The first notch is formed in a position that overlaps with the first antenna element and the second antenna element when the antenna device is viewed in plan. The antenna device according to claim 1.
4. The first notch is formed in a position that overlaps only with the first antenna element among the first and second antenna elements when the antenna device is viewed from above. The antenna device according to claim 1.
5. The side of the second antenna element faces the end of the side of the first antenna element. The antenna device according to any one of claims 1 to 4.
6. The side of the second antenna element faces the central part of the side of the first antenna element. The antenna device according to any one of claims 1 to 4.
7. The reflector further has a second notch formed on the second side of the reflector that extends in the second direction, having a second opening. The antenna device according to any one of claims 1 to 4.
8. The first side and the second side are the same side. The antenna device according to claim 7.
9. The first side and the second side are different sides. The antenna device according to claim 7.
10. The first notch and the second notch are formed in positions aligned in the first direction. The antenna device according to claim 9.
11. Furthermore, the substrate comprises a radiator formed on its upper surface and a reflector formed on its lower surface, The first notch region of the substrate has through-holes formed therein that connect to the first antenna element and through-holes formed therein that connect to the second antenna element. The antenna device according to claim 3.

Description

This disclosure relates to an antenna device, and more particularly to an antenna device having directionality and a structure that allows for miniaturization. In recent years, the adoption of IoT (Internet of Things) devices has been rapidly increasing worldwide. Antennas for IoT devices require miniaturization from the perspectives of design and portability. Furthermore, since the performance of the antenna is degraded by the presence of human bodies or metal objects nearby, it is necessary for the antenna to be robust against surrounding objects. To reduce the influence of surrounding metal objects, a unidirectional antenna is effective. Therefore, it is desirable for IoT device antennas to be small and unidirectional. Therefore, conventionally, antenna devices have been proposed that feature a miniaturized structure with an unpowered reflector facing the radiator, and where electromagnetic coupling between the radiator and the reflector enhances directivity toward the side opposite the reflector (see, for example, Patent Document 1). International Publication No. 2018/198349 Figure 1 is an external view showing the structure of the antenna device according to the first reference example.Figure 2 shows the antenna characteristics of the antenna device according to the first reference example.Figure 3 is a Smith chart showing the impedance characteristics when the length of the first antenna element is changed by 1 mm increments in the antenna device according to the first reference example.Figure 4 is a Smith chart showing the impedance characteristics when the length of the second antenna element is changed by 1 mm increments in the antenna device according to the first reference example.Figure 5 is an external view showing the structure of the antenna device according to the second reference example.Figure 6 shows the antenna characteristics of the antenna device according to the second reference example.Figure 7 is an external view showing the structure of the antenna device according to Embodiment 1.Figure 8 is an external view showing the structure of the antenna device according to Embodiment 1 of Embodiment 1.Figure 9 shows the antenna characteristics of the antenna device according to Embodiment 1 of Embodiment 1.Figure 10 is an external view showing the structure of the antenna device according to Embodiment 2 of Embodiment 1.Figure 11 shows the antenna characteristics of the antenna device according to Embodiment 2 of Embodiment 1.Figure 12 is an external view showing the structure of the antenna device according to Embodiment 3 of Embodiment 1.Figure 13 shows the antenna characteristics of the antenna device according to Embodiment 3 of Embodiment 1.Figure 14 is an external view showing the structure of the antenna device according to Embodiment 1 of Embodiment 2.Figure 15 shows the antenna characteristics of the antenna device according to Embodiment 1 of Embodiment 2.Figure 16 is an external view showing the structure of the antenna device according to Embodiment 2 of Embodiment 2.Figure 17 shows the antenna characteristics of the antenna device according to Embodiment 2 of Embodiment 2.Figure 18 is an external view showing the structure of the antenna device according to Embodiment 1 of Embodiment 3.Figure 19 shows the antenna characteristics of the antenna device according to Embodiment 1 of Embodiment 3.Figure 20 is an external view showing the structure of the antenna device according to Embodiment 2 of Embodiment 3.Figure 21 shows the antenna characteristics of the antenna device according to Embodiment 2 of Embodiment 3.Figure 22 is an external view showing the structure of the antenna device according to Embodiment 3 of Embodiment 3.Figure 23 shows the antenna characteristics of the antenna device according to Embodiment 3 of Embodiment 3.Figure 24 is an external view showing the structure of the antenna device according to Embodiment 4. (Antenna device as an example) Before describing embodiments of this disclosure, two examples of antenna devices for the 2.4 GHz band (with a roughly center frequency of 2.45 GHz and a wavelength of approximately 122 mm) based on the technology described in Patent Document 1 will be described as reference examples of antenna devices. (First reference example) Figure 1 is an external view showing the structure of the antenna device 9a according to the first reference example. More specifically, Figures 1(a) to (f) are a perspective view, top view, bottom view, side view, top dimension view, and bottom dimension view of the antenna device 9a, respectively. The antenna device 9a is a long, rectangular shape as a whole. The width direction is defined as the x-axis (also called the "first direction"), the direction perpendicular to the x-axis and extending along the length is defined as the y-axis (also called the "second direction"), and the direction perpendicular to both the x-axis and the y-axis is defined as the z-axis. The antenna device 9a is a dire