JPS58209204A - Antenna for direction finding - Google Patents

Abstract

PURPOSE:To attain the use of frequency bands of both antenna systems, by combining and incorporating a loop antenna system operatd at a low frequency band and an antenna group formed with dipole elements and the like operated at a high frequency band. CONSTITUTION:On a base 2 of a loop antenna 1 of orthogonal arrangement, a base 4 of an antenna 3 comprising a 4-element dipole is placed and they are incorporated. Since the operating frequency band of the antennas 1 and 3 is different, the mutual effect is less comparatively. Thus, the frequency band of both antenna systems is used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a direction-finding antenna.

There are many types of generally used direction finding antennas, such as loop antennas and atcoc antennas, and each antenna is selected and used according to its purpose based on its electrical characteristics, structure, and price.

Usually, due to electrical characteristics, loop antennas are used for long and medium wave bands, and whip antennas or atcock antennas that use dipole antennas are used for short waves and very high frequency bands. Loop antennas are often used for shortwave bands. However, recent mobile objects including ships are required to detect directions from the long to medium wave band to the very high frequency band. In this case, there are two types, one for low frequency band and one for high frequency band.
An fffl type antenna is required. In particular, since the measurement accuracy of a direction finding antenna is determined by its directivity, in many cases it is necessary to avoid the influence of the moving object itself.
It has a high mast and is placed on top of it. Therefore, an increase in the number of antennas requires a location with better conditions, so it is preferable to achieve the purpose with one antenna as much as possible.

The present invention solves this problem by combining and integrating a loop antenna system that operates in a low frequency band and an antenna group formed by dipole elements, etc. that operates in a high frequency band. It also features a direction finding antenna that can be used in the σ and &a bands.

FIG. 1 shows a perspective view of an embodiment of the present invention.
It has an integrated structure on which the base 4 of an antenna 3 made of a base dipole is mounted, and is fixed at the height of the base by means of a support 5. FIG. 2 shows this plan view, and as can be seen from the figure, each element of the four-element Idaiball antenna 3 is arranged so as to be located between each of the orthogonal loop antennas 1. .

Figure 3 shows a base 4t of a four-element dipole antenna 3 placed at the center of the same orthogonal loop antenna 1. It is supported by a support 16 made of material, such as an insulator. loop antenna 1
Regarding the relative position of and the four-element dipole antenna 3,
It is exactly the same as FIG. 2. Generally, direction finding antennas cause errors in direction measurement due to the presence of nearby disturbing objects.
It is a well-known fact that the degree of the error greatly depends on the resonance condition of the disturbing object. In the case of the combination of antennas according to the present invention, since the frequency bands used are different, their mutual influence is relatively small. Furthermore, even if an error occurs, since the arrangement is such that a mutual antenna balance is maintained as shown in FIG. 2, the error caused by mutual influence will appear as a quadrant error multiplied by n. In this way, it is easy to correct errors that appear as integral multiples of sine waves, so there is almost no problem.

The above description has only been made for the combination of two orthogonal loop antennas and a four-element dipole antenna, but even when multiple loop antennas are used, the corresponding antenna group of multiple-element dipole antennas must be placed in positions that maintain balance. By doing so, you can achieve your goals.

As can be seen from the above explanation, according to the present invention, two types of antennas with different frequency bands can be used as one antenna, so it is especially important to find a location with good installation conditions as a direction finding antenna. It has a great effect on ships and other transport vehicles.

[Brief explanation of drawings]

The drawings show an embodiment, and FIGS. 1 and 3 are perspective views, and FIG. 2 is a plan view. l...Loop antenna, 2...Base, 3! - Antenna, 4... Base, 5... Support, 6... Support. Patent Applicant Procedural Amendment (Method) September 20, 1980 Director General of the Patent Office 1. Indication of the Case Japanese Patent Application No. 57-91478 2. Name of the Invention Direction Finding Antenna, Person Making the Amendment Relationship with the Case Patent Applicant Ma 141 2-10-45 Kamitasaki, Tokyo Parts Ward, Showa 5
7 years and 31 days of the month (shipment date) 5. Amendment subject specification/drawing 6. Engraving of amendment content specification/drawing (no change in content)

Claims (1)

[Scope of Claims] l. A direction finding antenna in which the base of an antenna group formed by a plurality of dipoles is provided inside a plurality of intersecting loop antennas that use widely different frequency bands. 2. The bases of a plurality of intersecting loop antennas that use different frequency bands and the bases of an antenna group formed by a plurality of dipoles are integrated, and the unpatented scope of claim 1, item 111
1! direction finding antenna.