JPS60214605A - Printed dipole antenna - Google Patents

Abstract

PURPOSE:To improve reception sensitivity characteristics and to obtain symmetrical radiation directivity by connecting a passive element printed on the lengthwise axis of a dipole electrically to the dipole. CONSTITUTION:The radiation field of the antenna is directed in parallel to a dielectric substrate 1 with high-frequency currents which flow from dipoles 2a and 2b to passive elements 7a and 7b through a through hole 8. When the radio wave which has an electric field component E1 parallel to the substrate 1 and an electric field component E2 perpendicular to it arrives in a direction A, only the component E1 is received and the component E2 is not received. Therefore, the output of a coaxial plug 6 is a received current proportional to the amplitude intensity of the component E1 and the reception sensitivity characteristics are improved; and the dipoles 2a and 2b and elements 7a and 7b are symmetrical about the substrate 1 and radiation directivity has an excellent symmetrical pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a printed dipole antenna constructed using a dielectric substrate.

[Prior art]

Figure 1 is a diagram showing an example of a conventional printed dipole antenna. In Figure 1, (1) is a dielectric substrate, (2)
a) and (2b) are dipoles, (3a) and (
6b) is two parallel lines, (4) is a tapered balun, (5a
) is the center conductor, (5b) is the ground conductor, and (6) is the coaxial plug.

On the front and back sides of the dielectric substrate (1) are dipoles (2a) and (2b), two parallel wires (6a) and (sb), a Taber-shaped balun (4), a center conductor (5a), and a ground conductor (5b).
is printed and has an integrated structure.

Now, from the direction of A, the electric field component E parallel to the dielectric substrate (11)
Consider the case where a radio wave arrives with an electric field component E2 perpendicular to the dielectric substrate (11) and the dielectric substrate (11).Assuming an ideal dipole, among the electric field components E1 and E2, the dielectric substrate (1)
Only the electric field component B1 parallel to dipole (2a) and (
2b) and the electric field component E2 perpendicular to the dielectric substrate (11) is not received.
), the received current proportional to the pulse width strength of the electric field component E1 passes through two parallel wires (3a) and (6b), and is converted from a balanced current to an unbalanced current by a tapered balun (4). It flows into a microstrip line made up of a conductor (5a) and a ground conductor (5b), and is taken out as an output from a coaxial plug (6).

However, in an actual printed dipole antenna, the electric field on the dipoles (2a) and (2b) due to the thickness of the dielectric substrate (1) is
) is not parallel to the dielectric substrate (1
) and the electric field component E2 perpendicular to the dielectric substrate (11) as well as the electric field component E1 parallel to the dipole (2a) and (2b).
received at Since the value of the reception current received by the dipoles (2a) and (2b) is proportional to the component of the X red component EitE2 in the maximum reception direction of the dipoles (2a) and (2b), the thickness of the dielectric substrate (1) When the dog starts barking,
Alternatively, if the dielectric constant of the dielectric substrate (11 is high), the ratio of the receiving current 1 proportional to the amplitude intensity of the electric field component E1 to the receiving current I2 proportional to the amplitude intensity of the electric field component E2 is I2/1.
1 becomes large, and reception sensitivity characteristics deteriorate accordingly. Furthermore, the radiation directivity characteristics also have the disadvantage that the symmetry is lost due to the stepped shapes of the dipoles (2a) and (2b).

[Summary of the invention]

This invention was developed with the aim of improving these drawbacks, and by printing a parasitic element on the longitudinal axis of the dipole and making the upper and lower dipoles conductive with the parasitic element, This paper proposes a printed dipole antenna with good receiving sensitivity characteristics and radiation directivity characteristics.

[Embodiments of the invention]

FIG. 2 is a diagram showing an embodiment of the present invention.

fl) to (6) are exactly the same as the conventional printed dipole antenna shown in FIG. (7a) and (7b) are dipoles (2a) and (2b) respectively
A parasitic element printed on the longitudinal axis of the

(8) are upper and lower dipoles (2a) and (2b), respectively.
This is through-hole plating provided for electrical conduction between the parasitic elements (7a) and (7b).

FIG. 3(a) is for detailed explanation of this invention.

FIG. 3 is a cross-sectional view of one embodiment of the printed dipole antenna shown in FIG. 2; Dipole (2a) and (2b)
The parasitic elements (7a) and (7b), which are electrically connected through the through-hole plating (8), are connected to the dipole (2a).
Due to the high frequency current flowing from the top (2b) through the through-hole plating (8) to the parasitic elements (7a) and (7b), it exhibits characteristics similar to the positive dipoles (2a) and (2b). Therefore, the radiated electric field E of the printed dipole antenna according to the present invention is as shown in FIG. 3(b).
This is the vector sum of the radiated electric field component E5 due to the dipoles (2a) and (2b) and the radiated electric field component E4 due to the parasitic elements (7a) and (7b), and the dielectric substrate (1)
becomes parallel to.

In Figure 2, from the direction of A, an electric field component E1 parallel to the dielectric substrate (11) and an electric field component E1 perpendicular to the dielectric substrate (11).
Consider the case where a radio wave with 2 arrives.

As explained above, since the radiated electric field of the printed dipole antenna of the present invention is parallel to the dielectric substrate (1), only the electric field component E1 parallel to the dielectric substrate (1) is received by this antenna. The electric field component E2 perpendicular to the body substrate (1) is not received. Namely.

The output of the coaxial plug (6) is only the reception current 11 proportional to the amplitude strength of the electric field component E1 parallel to the dielectric substrate (1), resulting in good reception sensitivity characteristics. Also, dipole (2
a) and (2b) and parasitic elements (7a) and (7b)
) is symmetrical with respect to the dielectric substrate (1).

The radiation directivity characteristics have good symmetrical pattern.

Although the above description has been made for the case where the shape of the dipole and the parasitic element is rectangular, the same can be applied to cases where the dipole and the parasitic element have any shape such as a folded shape or a double-shouldered shape. Furthermore, the same method can be used when metal screws or the like are used for conduction between the dipole and the parasitic element.

[Effects of the Invention J] As explained above in this invention, a parasitic element is printed on the longitudinal axis of the dipole.

By making the dipole and the parasitic element electrically conductive, a printed dipole antenna with good receiving sensitivity characteristics and symmetrical radiation directivity characteristics can be obtained, which is a great effect.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a conventional printed dipole antenna, FIG. 2 is a diagram showing an embodiment of the present invention, and FIG. 3(a) is a diagram showing a detailed explanation of the present invention. FIG. 3(b) is a cross-sectional view of an embodiment of the present invention shown in FIG. In the figure, (1) is a dielectric substrate, (2a) and (2)
b) is a Goupole, (3,) and (3b) are two parallel wires, (4) is a tapered balun, (5a) is a center conductor,
(5b) is a ground conductor, (6) is a coaxial plug, (7a) and (7b) are parasitic elements, and (8) is through-hole plating. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa (7) Leg 1 Figure 2

Claims (1)

[Claims] In a printed dipole antenna in which a dipole and a dipole feed line are printed on both sides of a dielectric substrate, a parasitic element is printed on the axis in the length direction of the dipole, and each dipole and the parasitic element are electrically connected. A printed dipole antenna featuring: