JPH01272205A - Small-sized dipole antenna - Google Patents

Abstract

PURPOSE:To simplify and miniaturize a dipole antenna without degrading the radiation characteristic by setting dipoles, feeders, and matching circuits, which consist of a ceramic compound of an oxide superconductor, to both faces of a dielectric plate with desired shapes and dimensions. CONSTITUTION:Dipoles 1a and 1b, feeders 2a and 2b, and matching circuits 5a and 5b consist of a ceramic compound of an oxide superconductor and are set to both faces of a dielectric plate 6. Parts of dipoles 1a and 1b are formed on opposite sides of the dielectric plate 6. The matching circuit 5a is formed on the rear face of the dipole 1a, and the matching circuit 5b is formed on the rear face of the dipole 1b, and these matching circuits have a micro strip line structure. That is, since dipoles 1a and 1b, feeders 2a and 2b, and matching circuits 5a and 5b consist of a ceramic compound, a superconductive state is obtained at a higher temperature in comparison with a general metallic conductor and the loss resistance is easily set by zero. Thus, the radiation efficiency is easily improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention 1'j relates to a small dipole antenna for communications or radar that is used at relatively low frequencies in the HF band, VHF band, or υHF band.

[Conventional technology]

Figure 2 shows, for example, the original; "Small Antenna" 1. Journal of the Institute of Electronics and Communication Engineers, Vol-60e No. 4. p, 394 (
This is a structural diagram of a conventional small dipole antenna shown in 1972-4), and in the figure, (1g), (lb)
is a metal conductor dipole, (2m) and (2b) are power supply lines, (3) is a power supply circuit, and (4) is a power supply terminal pair.

The length 2L of the dipoles (la) and (lb) in Figure 1g2 is set to 0.1 wavelength or less for the purpose of miniaturization. Furthermore, in order to match the load connected to the resonant and feed terminal pair (4), a matching circuit (31) is connected to the feed line (2a), (2
It is connected after b).

Since the dipoles (im) and (lb) are minute dipoles, their radiation resistance is extremely small. Therefore, the entire antenna, including the matching circuit (31), is cooled with liquid helium to bring it into a superconducting state and reduce the loss resistance of the metal conductor to zero. Ta.

Here, the radiation efficiency η1 is expressed by the following equation.

However, the radiation power from the Pr1rl dipole, pLd is the power loss at the dipole, and Pjn is the power loss at the feed line and matching circuit. Pr is the dipole radiation resistance RT
Pjd - P4mu is proportional to the loss resistance R2 of each metal conductor.

From equation +11, it can be seen that the radiation efficiency increases if the loss resistance approaches zero.

[Problem to be solved by the invention]

Since the matching circuit (3) is connected to the dipoles (im) and (lb), it is difficult to support the antenna spatially, and the radiation characteristics deteriorate due to shielding of the support and matching circuit. There was a point.

Another problem with the structure of this small dipole antenna is that the cooling device using liquid helium is large and expensive, which is a problem in practical use.

This invention was made in order to solve the above-mentioned problems, and by mounting a dipole, a feed line, and a matching circuit on a dielectric plate and configuring it in a flat plate shape, it can be easily realized without completely deteriorating the radiation characteristics. The purpose is to obtain a small dipole antenna with this structure.

[Means for Solving the Problems] A small dipole antenna according to the present invention has a dipole, a feed line, and a matching circuit mounted on both sides of a dielectric material using a ceramic compound that is an oxide superconductor in a desired shape and size. .

[Effect]

The dipole, feed line, and matching circuit in this invention are constructed on a dielectric plate, and good radiation characteristics can be obtained.

〔Example〕

An embodiment of this invention will be described below. In Figure 1, (1m) and (lb) are rectangular plate-shaped dipoles, (2
m)-(2b) is a feed line, (5m) and (5b) are matching circuits formed by distributed constant lines, and (6) is a dielectric plate.

Dipole (1m) - (lb) e feed line (2m) -
(2b) - The matching circuits (5m) and (5b) are all made of a ceramic compound which is an oxide superconductor, and are attached to both sides of the dielectric plate (6).

Portions (10) and (1b) of the dipole are formed on opposite sides of the dielectric plate +61. The matching circuit (5-) is formed on the back surface of the dipole (1m), and the matching circuit (5b) is formed on the back surface of the dipole (To), each having a microstrip line structure.

Dipole (1m), (lb) e feed line (2m) -
(2b) #Matching circuit (5 sets), (5b) is made of a ceramic compound, so it can achieve a superconducting state at higher temperatures than ordinary metal conductors, and can easily reduce loss resistance to zero. It is possible. That is, radiation efficiency can be easily increased.

Although the case where the shape of one piece of the dipole is a rectangular plate has been described above, the present invention is not limited to this, and can be implemented in the same manner even when the shape is circular or oval. Moreover, although the case where the matching circuit is a microstrip line has been described, the same effect can be obtained when the matching circuit is connected as two parallel lines in the middle of the feed line.

〔Effect of the invention〕

As explained above, according to the present invention, the metal conductor is replaced with a ceramic compound, which is an oxide superconductor, and is constructed on a dielectric plate, making it possible to improve the dimensional accuracy of dipoles and matching circuits, as well as improve cooling. Since the entire device is inexpensive and can have a simple structure, such as one using liquid nitrogen, it is highly effective as a small dipole antenna for communications or radar.

[Brief explanation of the drawing]

Figure 1 is a structural diagram of a small dipole antenna according to an embodiment of the present invention, and Figure 1g2 is a structural diagram of a conventional small dipole antenna. (im), (lb) = dipole, (2m) - (2b
) - Feeding line, (31, (5m) - (5b)... matching circuit, (6)... dielectric plate. In the figure, the same reference numerals indicate the same or equivalent parts. Masuo

Claims (1)

[Claims] (1) In a small dipole antenna consisting of a dipole with a length of 0.1 wavelength or less and a matching circuit, the dipole and matching circuit are formed of a ceramic compound that is an oxide superconductor, and the dielectric plate is A small dipole antenna characterized by being attached to both sides or one side.