JPH05243804A - Microstrip line - Google Patents

Abstract

PURPOSE:To vary vertual line length by varying a propagation speed on a strip conductor without varying length of the strip conductor in a microstrip line. CONSTITUTION:On at least a part of an area in which a strip conductor 3 formed on a dielectric substrate 2 on a ground conductor plate 1 is extended and provided, dielectrics 5 whose dielectric constants are different are provided. For instance, a part of the dielectric substrate 2 is constituted of the dielectrics 5 whose dielectric constants are different, and a propagation speed on the strip conductor 3 of its part is varied so that the strip conductors of the same length can generate a phase difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave strip microstrip line, and more particularly to a microstrip line suitable for use as a transmission line for a transmitting / receiving antenna.

[0002]

2. Description of the Related Art Conventionally, a microstrip line used in the microwave band has a structure shown in FIG. This is one in which a dielectric substrate 2 is provided on a ground conductor plate 1 and a strip conductor 3 is laminated thereon. Further, FIG. 5B shows a dielectric conductor 2 and a ground conductor plate 1 which are further laminated on the strip conductor 3 having the above-mentioned structure. Can be suppressed.

[0003]

In recent years, a planar antenna to which the above-mentioned microstrip line is applied has been proposed. That is, a plurality of radiating elements are arranged on a dielectric substrate to form a planar antenna, and each radiating element is connected to a power feeding device with a strip conductor. Therefore, the feeding line length of the strip conductor is changed to feed the radiating element. Therefore, when each radiating element is arranged at the optimum position on the dielectric substrate, if the strip conductor is arranged so as to maintain a predetermined feeding phase difference, the shape of the strip conductor becomes complicated and the bent portion increases. This may cause unnecessary radiation or wiring may not be possible in some cases. An object of the present invention is to provide a microstrip line that can change the propagation velocity on the strip conductor to change the substantial line length without changing the length of the strip conductor.

[0004]

According to the present invention, dielectrics having different permittivities are provided in at least a part of a region where a strip conductor formed on a dielectric substrate is extended. For example, a part of the dielectric substrate is composed of dielectrics having different permittivities.

[0005]

By arranging the dielectrics having different permittivity partially, the propagation velocity on the strip conductor of the part is changed, and the phase difference can be generated even with the strip conductors of the same length.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing an embodiment in which the present invention is applied to a planar antenna, and FIGS. 2A and 2B are lines AA and B of FIG.
It is a -B line expanded sectional view. This forms a dielectric substrate 2 on a ground conductor plate 1 and arranges a plurality of radiating elements 4 thereon. Further, these radiating elements 4 are connected to a power feeding device (not shown) by a strip conductor 3. Then, on the dielectric substrate 2 where the strip conductor 3 is provided, a dielectric 5 having a partially different dielectric constant is provided.

According to this structure, even if the length of the strip conductor 3 is constant, the propagation speed in the strip conductor 3 is changed by providing the dielectrics 5 having different permittivities.
The feeding phases of the radiating elements 4 connected to the strip conductor 3 are made different from each other, and the feeding phase difference is given to each radiating element. Therefore, by adjusting the length and the dielectric constant of the dielectric body 5, the array factor can be tilted at an arbitrary angle,
Since the directivity of the antenna is represented by the product of the array factor and the element factor of the radiating element, the radiation directivity can be inclined in a desired direction.

By applying the present invention, FIG.
It is possible to adjust the phase of the pair array element for widening the transmission / reception frequency as shown in (a). or,
As shown in FIG. 3B, it is possible to use a dielectric 5 having a different permittivity on one of the two-point feed lines and give a phase difference to generate a circularly polarized wave. The electromagnetic coupling type in which the radiating element and the strip conductor are laminated via the dielectric substrate is also applied.

Further, as shown in FIG. 4A, the surface of the strip conductor 3 may be covered with a dielectric 5 having a different dielectric constant. Further, as shown in FIG. 4B, the dielectric substrate 2 and the ground conductor plate 1 are provided by providing the dielectric substances 5 having different dielectric constants.
The strip conductors 3 may be sandwiched between and.

[0010]

As described above, according to the present invention, since a dielectric material having a partially different dielectric constant is provided in a part of the strip conductor, by changing the propagation velocity on the strip conductor by the dielectric material, the strip conductor is changed. There is an effect that a phase difference can be given without changing the length of the conductor, a strip conductor can be easily wired, and transmission loss can be suppressed.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment in which the present invention is applied to a planar antenna.

2A and 2B are enlarged cross-sectional views taken along the lines AA and BB of FIG.

FIG. 3 is a partial plan view showing an application example of the present invention.

FIG. 4 is a sectional view of another embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional microstrip line.

[Explanation of symbols]

 1 ground conductor plate 2 dielectric substrate 3 strip conductor 4 radiating element 5 dielectric

Claims (2)

[Claims] 1. A microstrip line composed of a ground conductor plate, a dielectric substrate and a strip conductor, wherein dielectrics having different permittivities are arranged in at least a part of a region where the strip conductor extends. Micro strip line 2. The microstrip line according to claim 1, wherein a part of the dielectric substrate is composed of dielectrics having different dielectric constants.