JPS59196607A - Antenna for pulse radar - Google Patents

Abstract

PURPOSE:To obtain a pulse radar antenna not causing a pseudo echo by short- circuiting both ends of a triangular dipole antenna by means of a dielectric of inverse concaved type coated with a substance such as graphite. CONSTITUTION:A narrow pulse transmitted from a transmission side via a feeding connector 1 is applied to a central feeding terminal of the triangular dipole antenna 4 having a length of 1/2 wavelength via a broad band balun 2 and the current is progressed toward the outer side of the triangular dipole antenna from the feeding point. When the fundamental wave component is progressed by a 1/4 wavelength, the current is absorbed to the dielectric 5 of the inverse concaved form where graphite is coated on foamed polystyrol grains. Thus, the pulse current returning from the open end of the triangular dipole antenna 4 to the feeding point is caused by the mismatching between the open end and the connecting part of the dielectric 5, thereby decreasing the loss to a minute value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pulse radar antenna that performs R1 measurement of a nearby object using pulses with a narrow 01 width.

In general, large-diameter rod-shaped tie-ball/amplifiers and flat-plate triangular gui-ball amplifiers are known to have constant impedance characteristics over a wide band ((13). , 1 The above-mentioned fundapu is not used.-IB self-fundament [Mannon] The electric current iAt traveling towards the end between the feed point 1p and h''l is reflected at the open end and ash is sent to the feed point. After that, 6Q waves are mixed at the same time, resulting in standing wave excitation. When a 5f pulse is applied, the traveling wave current from the feeding point to the 11th point causes the C pulse to be 01JL, and the remaining energy is reversed by the open OFF and returns to the JJL voltage point as a backward wave. There is a phenomenon in which the antenna re-swords when returning to the ground, and if the above-mentioned antenna is used as an antenna for a pulse generator, it has the disadvantage of producing a false echo. /7 length of -1/'2 waves, and a current of about 1/4 wavelength (runs 1; By inserting an appropriate resistance at the position where Ff?
'j 'IJ was caused by the noise, but the difference between the antenna becomes large, and there is a foul wave between the open end of the amplifier and the loading resistor, and it is strange that it is successful. ,
In order to provide directivity only in one direction and eliminate unnecessary radiation components (this requires a seal 1 to Coos that also serves as a reflection plate, but the pressure between the reflector and the antenna narrows the constant impedance characteristic of the antenna. There was a drawback.

The present invention eliminates this drawback and provides a pulselator antenna that has broadband constant impedance characteristics and is capable of suppressing repulsive waves from the open end of the diagonal dipole antenna. This will be explained in detail below with reference to the drawings.

1 and 2 show an embodiment of the present invention.
In the J vertical cross-sectional view and the A-Δ' cross-sectional view, 1 is a power supply connector, 2 is a wide band 1g balun as a balanced unbalanced converter, and 3
4 is a dielectric substrate; 4 is a triangular type pole antenna formed by etching a metal plate fixed on the substrate 3; 11 - A dielectric material made by moving the graph 1 to 1 -1-7-4 to the particles of 11-1 and making it into a reverse circular shape. (Mayo angle 1 (ratai ball) lance 4 and gold Ii
l Temporary sticker!・/7-space (a space formed by surrounding the transmitter (not shown)'/J's power supply -=1 A narrow pulse sent through the [
j, 1,72 of the pulse fundamental wave through the broadband balun 2
The central feeding terminal of the monogonal evening/r pole antenna 4 having a wavelength length is applied, and the current travels from the feeding point to the triangular tie ball antenna 4 toward the i side. The fundamental wave component is 1.・When the wavelength propagates over, the current is absorbed by the inverted gate-shaped dielectric material 5, which is made of, for example, foamed polyester and graphite. E5 LJJ:: It is connected at both open ends of the I'i' type 1 dipole antenna 4, and extends vertically from one open end <:h:> toward the reflector (61) n>. The antenna is folded back in a reverse gate shape between the four reflectors,
It is connected to the b'i end between the other horns, and there is a space 7 between the dielectric 5 and the center of the antenna. For example, the current flowing through the graphs 1~ advances from one end of the triangular dipole antenna 4 to the other end, but because the resistivity of the gelatin sheet is large, the traveling wave current is converted into thermal energy, which is absorbed by the dielectric 5. be done. Therefore, the pulse current that returns from the open end of the triangular Guipole antenna 4 to the feeding point is caused by the mismatch between the open end and the dielectric 5 connection J:
Ruda(p) and this m +, ;i becomes infinitesimal.

In addition, a pulse (J mentioned above dielectric 5
determines the characteristic of absorbing radio waves over a wide band, and the effect of its use in the shield case 6, the reduction of Q and tl in the anti-body opening N, and the influence of the foul wave on the impedance of the antenna is Small, triangular ball with 11 areas and 1"/:L
I can do it.

As explained above, the space between the triangular dipole antenna 4 and the shield case 6 is used to short-circuit both ends of the triangular dipole antenna 4 with, for example, an inverted gate-shaped dielectric material 5 coated with graphite. By doing this, reflections from the open end of the antenna are suppressed, and J
The pulse spread out to the side of the shield non-north G (J: due to the above dielectric 5, the above 7 non-north J4 is used as an antenna for a pulse generator, 1 pseudo It has the effect of being suppressed.

[Brief Description of the Drawings] Figures 1 and 2 are vertical cross-sectional views showing an embodiment of the base 4 (I L Ming J/n)-゛ and △ △' 1iJ
1. Power supply connector, 2. Broadband balun,
3...Dielectric substrate, 4...Triangular tie ball ande. 5... Dielectric property ((a inverse concave dielectric 7[i (4\,
6...Metal plate shield case, 7...Space 4'f WF Applicant [1 Mizubu 1 (! Red J Stock 1 (Meeting 11) Hon Telegraph and Telephone Public Service]

Claims (1)

[Claims] On one side of the dielectric M plate, there is a triangular I (metal plate) arranged and fixed with the apex angles facing each other, and a triangular tie ball antenna in order to radiate the electromagnetic waves from the triangular tie ball antenna in one direction. A metal plate shield case arranged in parallel with the triangular tie ball antenna, and an inverted convex dielectric with W conductivity placed in the space formed between the triangular tie ball antenna and the metal plate seal. , and connect both legs f and 1 of the inversely convex dielectric body to both open ends of the triangular Guiball ann (2), and carefully press the leg ends f and 1 to avoid contact with each other. A nonontenna for a pulselator characterized by suppressing reciprocal waves from the open end.