JPS596602A - Ferrite antenna coil - Google Patents

Abstract

PURPOSE:To display the performance of a ferrite core sufficiently by winding a single layer solenoid winding around the rod-like ferrite core at a part more than a specific length out of the whole length and winding the center part with higher density as compared to the right and left winding parts. CONSTITUTION:The single layer solenoid winding 12 is wound around the rod- like ferrite core 11 at a part >=2/3 the whole length with distributed density at both end parts and high density at the center part. In another example, a concentrated winding coil 15a obtained by winding the solenoid coil thickly is wound around the ferrite core 14 at its center and distributed winding coils 15b are wound at both right and left winding parts.

Description

[Detailed description of the invention] Regarding Elite antenna coil.

A conventional ferrite antenna coil is shown in front view in FIGS. 1 and 2. In the figure, (1) is the core, (2) is the coil tightly wound in the center, (3) is the coil lead, and in Figure 2, (4) is the ferrite core, (5) is the distributed coil, (6) is the coil lead. ) indicates a coil lead.

The above-mentioned conventional structure has the drawback that the performance of the ferrite core cannot be fully utilized depending on the winding method, and the desired gain cannot be obtained.

The purpose of the present invention is to fully demonstrate the performance of a ferrite core and obtain a high gain.

Configuration 1 of the ferrite antenna coil of the present invention In a ferrite antenna coil configured by winding a single-layer solenoid winding around a rod-shaped ferrite core, the single-layer solenoid winding is arranged at least two-thirds or more of the total length of the rod-shaped ferrite core. It is characterized by the winding, and the winding density in the central part is denser than in the left and right winding parts.

The ferrite antenna coil of the present invention will be explained based on examples.

FIG. 3 shows a front view of a ferrite antenna coil according to an embodiment of the present invention.

In the figure, (11) is a rod-shaped ferrite core, (12
) indicates a single-phase solenoid winding coil, and (13) indicates a coil lead.

In the present invention, the single-phase solenoid winding is wound on a 2/3 or more rod-shaped ferrite core from both ends at first in a distributed manner, and then sequentially toward the center line x-x' with a higher winding density. Wind it so that it becomes larger.

FIG. 4 shows a front view of a ferrite antenna coil according to another embodiment of the present invention.

In the figure, (14) is a rod-shaped ferrite core, (15
b) is a distributed winding coil, (15a) is a concentrated winding coil, (1
6) indicates a coil lead.

In the second embodiment of the present invention, a concentrated winding coil (15b) in which lunoid windings are closely wound is connected to a ferrite core (14b).
), a distributed winding coil (15a) is wound around both left and right winding parts.

The gain of a ferrite antenna coil is proportional to μe and Qe, where the effective permittivity μe and the effective Q are Qe, and /le
In general, as shown in Fig. 5, in a rod-shaped ferrite core, the magnetic flux convergence rate, in other words, the effective magnetic permeability μe is highest at the longitudinal center of the core. ,
Small enough to reach the edge. Figure 6 is similar to Figures 1, 2 and 3.
The induced energy for each coil turn in the ferrite antenna coils C1, C2, and C3 shown in the figure is simply expressed for the purpose of explanation. The sum of induced energy, ie, the gain, increases.

The configuration shown in FIG. 4 also produces the same effects as the first embodiment.

Effects of the present invention FIG. 7 shows the ferrite antenna coil (AI) in FIG.
(A2) in Figure 2, (A3) in Figure 3, and (A3) in Figure 4.
4) shows a diagram of the relationship between the signal frequency (MH2) and gain. As shown in the figure, it can be seen that the gain of the ferrite antenna coil of the present invention is superior to that of the conventional one. On the other hand, if the gain is the same, it can be made smaller.

[Brief explanation of the drawing]

Fig. 1 is a front view of a conventional closely wound ferrite antenna coil, Fig. 2 is a front view of a conventional ferrite antenna coil with uniformly spaced distributed winding, and Fig. 3 is a front view of a ferrite antenna coil of the present invention. FIG. 4 is a front view of another embodiment of the present invention, FIG. 5 is a distribution diagram of effective magnetic permeability of a conventional ferrite antenna coil, and FIG. 6 is a ferrite antenna of the conventional and present invention. Fig. 7 is a comparison diagram of the longitudinal position of the coil and the induced energy, and shows the reception frequency (MH
2) and a comparison diagram of gain. 11.14: Rod-shaped ferrite core 12: Coil 1
3.16: Coil lead 15a: Concentrated winding coil 15
b Two-distribution winding coil patent applicant Matsushita Electric Industrial Co., Ltd. Agent Patent attorney Isao Abe Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. The single-phase solenoid winding is wound around 2/3 or more of the rod-shaped ferrite core, starting from both ends with distributed winding, and in the center the density is higher than that of distributed winding. A ferrite antenna coil 2 having a winding portion, the ferrite antenna according to claim 1, wherein the winding portion in the central portion is oriented toward the center line of the central portion from the distributed winding portion and the winding density is increased sequentially. Coil 3: The ferrite antenna coil according to claim 1, wherein the central winding portion is configured to have a concentrated winding with a winding density higher than that of the distributed winding.