JPH03148902A - Plane antenna - Google Patents

Abstract

PURPOSE:To improve a whole gain and to make a band high by electro-magnetically connecting radiation elements such as patch antennas at the termination part of micro strip lines. CONSTITUTION:Ground conductors 12 are provided for the whole surface of one side of a dielectric board 10. The crank-formed micro strip lines 14 and 16 are provided for the other side of the dielectric board 10. The starting end- side of the micro strip lines 14 and 16 is set to be common and the sides of the terminations are electro-magnetically connected to patch antennas 18 and 20. Plural pairs of micro strip lines 14 and 16 are actually provided so as to constitute a micro strip line array antenna.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flat antenna used, for example, for receiving satellite communications.

[Prior Art] Various types of planar antennas are known as the above-mentioned planar antennas, among which a grounding conductor is provided on one surface of a dielectric plate and a micro-conductor is provided as a radiation conductor on the other surface. There is a microstripline antenna with a stripline. In order to achieve a high gain in this microstrip line antenna, it is necessary to prevent reflection at the terminal end of the microstrip line. There.

Conventionally, as means for preventing reflection, the means shown in FIGS. 7 to 9 have been proposed. That is, itta electric board, 2 is a ground conductor, 3 is a microstrip line, and a chip resistor serving as an absorption resistance is connected between the terminal end of this microstrip line 3 and a conductor alG4 which is at the same ground potential as the ground conductor. 5 is soldered. In this way,
Although reflection at the end of the microstrip line 3 can be prevented, the chip resistor 5 consumes the power remaining at the end, causing power loss.

As shown in Figs. 10 and 11, a method for preventing such power loss has been proposed (Japanese Patent Laid-Open No. 6
1-167203), in which a ground conductor 2 and a microstrip line 3 are provided on a dielectric plate l in the same way as described above, and a batch antenna 6a whose impedance is matched is provided at the terminal end of this microstrip line 3. 6b is coupled in the same plane as the microstrip line 3, and after preventing the generation of reflected waves, all the power remaining at the terminal end is radiated by the batch antenna.

[Problem to be Solved by the Invention 1] However, in the planar antenna shown in FIG. 10 and FIG. When combining with the line antenna 3, there was a problem that the combined band became narrow. That is, the first
In Figure 2, the dashed line shows the frequency vs. gain characteristics of the microstrip line antenna, the dotted line shows the frequency vs. gain characteristics of the batch antenna 6a or 6b, and the solid line shows the frequency vs. gain characteristics of the microstrip line antenna. A tenth antenna combining the antenna and batch antenna 6a or 6b
This is the frequency vs. gain characteristic of the planar antenna shown in Fig. 11 and Fig. 11. As is clear from this, by adding the batch antenna 6a or 6b, the gain at the center frequency of 1° has increased, but the band The problem was that it was narrower than a microstripline antenna with a chip resistor connected to the end.

An object of the present invention is to provide a planar antenna that solves the above problems.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a ground conductor on one side of the dielectric board and a microstrip line on the other side of the yA electric board. A radiating element impedance-matched to the microstrip line is provided at intervals in the −F direction of the terminal end of the microstriff brine, and this radiating element is electromagnetically coupled to the terminal end of the microstriff brine. be.

When the microstrip line and the radiating element are fused together by TL, the air between them can be used as a dielectric, but it is also possible to provide a dielectric plate between them.

[Function] According to the present invention, impedance matching is achieved between the radiating element and the microstrip line, so no reflection occurs at the end of the microstrip line, and the power remaining at the end of the microstrip line is radiated from the radiating element. At this time, the radiating element is electromagnetically coupled to the microstrip line, so it has a wide band.

The planar antenna according to the present invention has an improved gain and a wide band.

[Example] A first example is shown in FIGS. 1 to 5. In this example, as shown in FIG. It is provided. d electric board l
On the other side of O, crank-shaped microstrip lines 14 and 16 are provided, as shown in FIG.

These microstrip lines +4 and 16 have a common starting end, but each microstrip line has a common starting end.
It is electromagnetically coupled to a planar antenna 18.20. In addition,
The figure shows a pair of microstrip line antennas 14.
．． Although In is not shown, in reality, multiple pairs of such microstrip lines 14 and 16 are provided,
It is configured as a microstrip line array antenna.

That is, as shown enlarged in FIG. 2, the terminal end of each microstrip line 14.16 is connected to the phase adjustment line 22.16.
24. It is coupled to a capacitively coupled power supply line: lO, 32 via an input and /4 transformer 26, 28. A dielectric plate 4 is disposed above these power supply lines IO, 32, and batch antennas ta, zo are provided on this dielectric plate 34 so as to be electromagnetically coupled to the power supply lines IO, 2.

The feed line 30.32 has a rectangular shape with a width of W and a length of L, and W and L are designed to achieve impedance matching with the batch antenna 18.20. Also,
As shown in No. 41f4, the batch antennas ta and zo are formed by cutting the lower left and upper right diagonals of the square batch antenna when viewed from the feed line so as to generate right-handed circularly polarized waves. Also. The length of one side is selected to resonate at the design frequency. Batch antenna 1
8. The ratio of the total area before cutting to the area after cutting in 20 is called the cut rate, and since there is some variation in the center frequency due to changes in this cut rate, it is defined as the cut rate,
There is a correlation between them. Also. Both batch antenna 1
8.20 are formed on the dielectric plate 34 so that the distance between their respective centers is equal to the distance aD between the right end midpoints F of the power supply lines 30 and 32 shown in FIG. The dielectric plate 34 is arranged so that the center of the batch antenna 18.20 is located on the intermediate point F. This is to increase the degree of freedom in design. Also. Each pressure @D is equal to each microstrip line 14 when used as an array antenna.
．． The IGs are set to be equally spaced.

The reason why the λ,/4 transformer 26%28 is provided is as follows. Since the input impedance of the batch antenna 18.20, which is an electromagnetic coupling type, is low, this and the feed line 30,
32, the feed line width W becomes thicker. Considering the loss in this power supply line, it is better to make the power supply line as short as possible.

Also. Crank-shaped microstrip line 14.1
It is also desirable that the line from 6 to the power supply line JO, 32 be thinner in terms of low loss and ease of design. Therefore, the microstrip line 14.
Reference numeral 16 indicates a thin line, for example, a width l×1. As a result, input and /4 transformers 26 and 28 are provided to match the two. Note that λ is the line wavelength. Also. If the phase of the traveling wave propagating through each front microstrip line 14.16 and the phase of the batch antenna 18.20 are not aligned, the gain will not be maximized. 24 is provided.

In FIG. 5, the one-dot chain line shows the frequency vs. gain characteristics of only the microstrip lines I4 and 6, the dotted line shows the frequency vs. gain characteristics of the batch antennas 18 and 20, and the solid line shows the frequency of this embodiment. This is a gain versus gain characteristic. As can be seen from this Figure 5, batch antenna 18.2
By electromagnetically coupling 0 to the miked strip lines 14 and 16, the overall gain is increased and the band is increased.

A second embodiment is shown in FIG.

Feed line: The dielectric plate 34 is not provided between the IO, 32 and the batch antenna 18, 20, and an air layer is used as the dielectric. 34a is the batch antenna 18
, 20, and is coupled to the dielectric plate 10 at a position not shown. Using an air layer as a dielectric in this way increases efficiency slightly.

However, in order to generate left-handed circularly polarized waves, it is sufficient to cut both diagonals of the lower right corner and the left-handed corner.Also, in the above embodiment, the case where circularly polarized waves are generated was explained. It is also possible to generate linearly polarized waves. Furthermore, although a square antenna was used for the batch antenna 18.20,
Rectangular or circular shapes can also be used.

[Effects of the Invention] As explained above, in the present invention, since a radiation dissipator such as a batch antenna is electromagnetically coupled to the terminal end of a microstrip line, the overall gain is improved and the band is increased. be able to.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted plan view of a first embodiment of a planar antenna according to the present invention, FIG. 2 is an enlarged plan view of main parts of the first embodiment, and FIG. 3 is a plan view of the first embodiment. Longitudinal cross-sectional view of main parts,
Fig. 4 is a plan view of the batch antenna used in the first embodiment, Fig. 5 is a frequency vs. gain characteristic diagram of the first embodiment, and Fig. 6 is a main view of the second embodiment. Longitudinal sectional view of the section, No. 7
The figure is a partially omitted plan view of an example of a conventional planar antenna.
The figure is an enlarged plan view of the main part of the planar antenna in Figure 7, and Figure 9.
The figure is a longitudinal sectional view of the main part of the planar antenna in Figure 7, 281
Figure 0 is a partially omitted plan view of another example of a conventional planar antenna.
FIG. 11 is a partially omitted plan view of still another example of a conventional planar antenna, and FIG. 12 is a frequency versus gain characteristic diagram of the planar antenna shown in FIGS. 10 and 11. lO...dielectric plate, 12...ground conductor, 14.
1t...-Microstrip line, 18.20.
...Batch antenna. Patent Applicant Diex Antenna Co., Ltd. Representative Tetsu Shimizu and 2 others Figure 1 %2 Figure 3 Akira 4th i'1 Figure 5 RePJ6I! 101f\
34a Bald 7 Figure 8th %91ii0 Figure 10! S11 Group-A''suko 12 figure h f

Claims (2)

[Claims] (1) A dielectric plate provided with a grounding conductor on one surface, a microstrip line provided on the other surface of this dielectric plate, and the A planar antenna comprising a radiating element electromagnetically coupled to a microstrip line and impedance matched to the microstrip line. (2) The planar antenna according to claim 1, further comprising a dielectric plate between the terminal end of the microstrip antenna and the radiating element.