JP3171898B2 - Microstrip antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microstrip antenna used for mobile communication, for example.

[0002]

2. Description of the Related Art A conventional microstrip antenna will be described with reference to FIG.

[0003] Reference numeral 11 denotes a first dielectric substrate on which a plurality of radiating elements 12 are formed. This radiating element 12
Is formed, for example, by using a dielectric substrate with a copper-clad surface and leaving a portion to be a radiating element by an etching technique.

[0004] A second dielectric substrate 13 is in contact with the first dielectric substrate 11. On an upper surface of the second dielectric substrate 13, for example, a surface in contact with the first dielectric substrate 11, a transmission line network (not shown) for supplying a signal to the radiating element is formed. The transmission network has a number of branches for transmitting a signal to each radiating element, and one branch is electrically connected to one radiating element.

[0005]

For example, in a microstrip antenna used for mobile communication, there is a case where it is desired to use a curved strip so as to fit the outer shape of the mobile body. However, in the above-described microstrip antenna, a dielectric substrate in which glass fiber is hardened with epoxy resin or the like is often used. Such a dielectric substrate,
Due to the lack of flexibility, it was difficult to form a curved surface. Further, these materials have a large weight, so that it is difficult to reduce the weight.

An object of the present invention is to provide a microstrip antenna which is flexible and can be formed into a curved surface.

[0007]

The microstrip antenna of the present invention uses a flexible film as a dielectric substrate, and forms a plurality of radiating elements and transmission paths for signal feeding on the dielectric film surface. In addition, these are sealed together with a coaxial line for signal supply in a dielectric bag whose inside is in a vacuum state.

[0008]

According to the present invention, since a plurality of radiating elements, transmission paths for signal feeding, and the like are formed on the dielectric film surface,
It is flexible and can also be reduced in weight.

[0009]

An embodiment of the present invention will be described below with reference to FIG. FIG. 1A is a perspective view showing the present invention,
FIG. 1B is a view schematically showing a state in which some components of the present invention are stacked.

Reference numeral 21 denotes a first dielectric film, on which a plurality of radiating elements 22 are formed. The radiating element 22 is formed, for example, by using a dielectric film having a conductive film formed on its surface, and leaving a part to be a radiating element by an etching technique.

Reference numeral 23 denotes a second dielectric film,
On an upper surface of the second dielectric film 23, for example, a surface on the first dielectric film 21 side, a transmission path network 24 for transmitting a signal to the radiating element is formed. This transmission path network 2
4 has a plurality of branches for transmitting a signal to each of the radiating elements 22, and one branch is configured to be individually electrically coupled to one radiating element. For example, a slit is provided at the center of each radiating element, and is electromagnetically coupled to the tip of a branch extending near each radiating element.

A third dielectric film 25 is provided below the second dielectric film 23, and a conductor film 26 is formed on the surface of the third dielectric film 25. This conductor film 26 functions as a ground conductor.

Between the first dielectric film 21 and the second dielectric film 23, a first flexible spacer 27 such as foamed polyethylene is disposed. Further, a second spacer 28 such as foamed polyethylene similar to the first spacer 27 is disposed between the second dielectric film 23 and the third dielectric film 25. The first and second spacers 27, 2
Numeral 8 is for holding each film at a predetermined interval.

A coaxial line 29 is connected to the transmission line network 24 for supplying a signal to the transmission line network 24 formed on the surface of the second dielectric film 23.

Each of the dielectric films 2 arranged as described above
1, 23, 25, each spacer 27, 28 and the line portion of the coaxial line are housed in a dielectric bag 30, and the inside thereof is evacuated. It is desirable that the sealed portion of the coaxial line be sealed by heat fusion or the like so that air does not leak. Also, one end of the coaxial line extends out of the bag 30 so that it can be connected to a signal source (not shown).

In the above-described embodiment, the case where the first dielectric film having a plurality of radiating elements formed on the surface has been described as a single layer, but the first dielectric film having the radiating elements formed thereon has been described. May be formed of a plurality of layers. In this case, the bandwidth of the antenna can be widened by making the size and shape of the radiating element different from each other for each layer of the dielectric film.

[0017]

As described above, according to the microstrip antenna of the present invention, since it has flexibility, it can be easily formed into a curved surface, and its weight can be reduced. Further, since an adhesive is not necessarily required, in this case, a change in antenna characteristics due to the influence of the dielectric constant of the adhesive can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram illustrating a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 ... First dielectric film 22 ... Radiating element 23 ... Second dielectric film 24 ... Transmission line network 25 ... Third dielectric film 26 ... Conductor film 27, 28 ... Spacer 29 ... Coaxial line 30 ... Bag

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01Q 1/00-1/10 H01Q 1/27-1/52 H01Q 13/00-13/28

Claims (2)

(57) [Claims] 1. A first dielectric film having a plurality of radiating elements formed on a surface thereof, a second dielectric film having a transmission path network for feeding signals to the plurality of radiating elements formed on a surface thereof, A third dielectric film having a conductive film serving as a ground conductor of the transmission line formed on a surface thereof, a coaxial line for supplying a signal to the transmission line, the first dielectric film, and the second dielectric film. First and second spacers respectively arranged between the film and between the second dielectric film and the third dielectric film, and holding each film at a predetermined interval; The dielectric film, the spacers, and the line portions of the coaxial lines are housed therein, and the inside is evacuated to seal the dielectric films, the spacers, and the line portions of the coaxial lines. Micros with bag Trip antenna. 2. The microstrip antenna according to claim 1, wherein a plurality of first dielectric films each having a plurality of radiation elements formed on a surface thereof are formed.