JPS63151101A - Micro strip antenna - Google Patents

Abstract

PURPOSE:To select plural resonance frequencies by electrically adjusting the depth of a recessed part of a conductive plate provided on the reflector/radiator side of a dielectric plate. CONSTITUTION:When a bias voltage is not applied to a bias line 8, the recessed part formed with a hole of a ground plate 4 and a recessed part of a base plate 5 resonates with the frequency determined by the depth and the radius of the whole of an upper cavity 9 and a lower cavity 10, the radius of a radiator 2, and the thickness and the dielectric constant of a dielectric plate 1 because a diode 7 is turned off. When the bias voltage is applied to the bias line 8, the recessed part resonates with the frequency determined by the depth and the radius of the upper cavity 9, the radius of the radiator 2, and the thickness and the dielectric constant of the dielectric plate 1 because the diode 7 is turned on and the recessed part is electrically formed with only the upper cavity 9. If there are two frequencies to be used, dimensions of respective parts are set to proper values and the frequency is switched by applying or not applying the bias voltage to the bias line 8.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a microstrip antenna used as a termination of a microwave or millimeter wave transmission line, and in particular,
This invention relates to a microstrip antenna whose resonant frequency can be changed.

[Prior Art] This type of microstrip antenna generally has a configuration in which a radiator made of a conductive material (metallic material) and a ground plate made of a conductive material (metallic material) are arranged with a dielectric plate in between. It becomes. The resonant frequency in this configuration is determined by the two dimensions of the radiator, the thickness of the dielectric plate □, and its dielectric constant.・ [Problems to be solved] In microwave and millimeter wave band wireless transmission systems that use the microcostrip antenna mentioned in 1 above, efforts have recently been made to make effective use of frequencies, including time-division communications. It has become to. In this case, due to advances in integrated circuit technology, digital technology, etc., even a single transmitter/receiver can generate radio waves of different frequencies, but antennas differ depending on their shape, material, etc. A single usable frequency, that is, a resonant frequency is determined.

On the other hand, in a system using microstrip as a line, small, light fi1. Microstrips are used because they have the advantage of being suitable for fi production. For this reason, it can be said that the conventional antenna, in which a large number of antennas for different operating frequencies must be attached to a single multi-frequency transceiver, is unreasonable.

Therefore, an object of the present invention is to provide a microstrip antenna whose resonant frequency can be changed.

[Means for Solving Problems] In order to solve the above-mentioned problems and achieve the object, the present invention is constructed by taking the following measures. Namely, the microstrip antenna according to the present invention includes a dielectric plate, a radiator made of a conductive material arranged on one side of the dielectric plate, and a radiator arranged on the other side of the dielectric plate corresponding to the radiator. A conductive plate having four parts having substantially the same shape in plan and having a predetermined depth dimension, and an adjusting means for adjusting the electrical depth dimension of the four parts of the conductive plate. This is the composition.

' [Example] Hereinafter, an example of the microstrip antenna according to the present invention will be described with reference to the drawings.

1 is a plan view of the embodiment, FIG. 2 is a cross-sectional view taken along the line A--A in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line B--B in FIG.

As shown in FIGS. 1 to 3, on the top surface of the dielectric plate 1,
A circular conductor radiator 2 made of a thin metal plate is installed, and a microstrip line 3 provided on the A electric body plate 1 is connected to the radiator 2, and a power supply line is connected to the radiator 2. It consists of

Further, a conductive ground plate 4 made of a thin metal plate is installed on the lower surface of the dielectric plate l. Radiator 2 of this ground plate 4
The part corresponding directly below has almost the same shape as the radiator 2, and
A hole with a similar size area has been removed. A base plate 5 made of a metal material is bonded below the ground plate 4. Similar to the ground plate 4, this base plate 5 also has a hole formed in a portion directly below the radiator 2. What is the area of this hole?

This hole, which is equal to the hole in the ground plate 4 and does not pass through the base plate 5, is formed as a cylindrical recess (cavity) with a bottom. A separator 6 is provided in which a thin metal plate is bonded to the dielectric material to be divided.

The metal plate on this separator 6 has almost the same shape as the radiator 2, but has a slightly smaller area, and a plurality of diodes 7 are arranged between the edge of the metal plate and the wall of the recess in the base plate 5. connected above.

In order to apply a bias voltage to these diodes 7, a bias line 8 made of a metal material is provided extending from the bottom of the base plate 5 to the metal plate of the separator 6. This bias line 8 is electrically insulated from the base plate 5. Note that the upper side of the recess divided by the separator 6 is the upper cavity 9, and the lower side is the lower cavity l.
Let it be O.

Next, the operation of this embodiment configured as described above will be explained.

That is, if a bias voltage is not applied to the bias line 8, the diode 7 is OFF, so the recess has a depth of the entire upper cavity 9 and lower cavity 10,
It resonates at a frequency determined by the radius, the thickness of the 1M radius electric plate l of the radiator 2, and the dielectric constant.

On the other hand, when a bias voltage is applied to the bias line 8, the diode 7 is turned on and the recess is electrically limited to the upper cavity 9, so that the depth and radius of the upper cavity 9 and the radius of the radiator 2.

It resonates at a frequency determined by the thickness and dielectric constant of the dielectric plate l.

Therefore, if you have two frequencies that you want to use in advance,
By appropriately selecting the dimensions of each part, the frequency can be switched depending on whether or not a bias voltage is applied to the bias line 8.

In the above embodiment, the case where the radiator 2 is circular is described, but any shape such as a rectangle, a polygon, an ellipse, etc. can be applied. Further, the ground plate 4 may be used in common with the base plate 5. In this case, the base plate 5 is used as the dielectric plate 1.
The structure is such that it can be directly adhered to.

Furthermore, in the above embodiment, the lower four parts of the dielectric plate 1 are
Although the upper and lower parts are divided by one separator 6, if the separators 6 are provided in multiple stages in the depth direction of the four parts to obtain the desired electrical depth, one antenna can be divided into multiple parts. frequency can be selected.

[Effects of the Invention] As described above, in the present invention, a plurality of resonant frequencies can be selected by electrically adjusting the depth of the recessed portion of the conductive plate provided on the anti-radiator side of the dielectric plate. effective.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of a microstrip antenna according to the present invention. Figure 2 is a sectional view taken along line A-A in Figure 1;
FIG. 3 is a sectional view taken along the line B--B in FIG. 2. l: dielectric plate 2: radiator 3: microstrip line 4 Nigerland plate 5: base plate 6: separator 7: diode 8: bias line 9: upper cavity 10: lower cavity

Claims (1)

[Claims] A dielectric plate, a radiator made of a conductive material disposed on one side of the dielectric plate, and a portion corresponding to the radiator disposed on the other side of the dielectric plate have substantially the same shape in a plane. , and a conductive plate in which a recessed portion having a predetermined depth dimension is formed;
A microstrip antenna characterized by comprising an adjusting means for adjusting the electrical depth dimension of the recessed portion of the conductive plate.