JPH0870208A - Strip line resonator - Google Patents

Abstract

PURPOSE: To make the resonator small by selecting an interval between strip lines to be a specific value with respect to a line width. CONSTITUTION: A 1st strip line 1 whose line width is W1 and line length is L1 and a 2nd strip line 2 are arranged almost in parallel side by side at an inter-line interval (s) less than 1/3 of the line width W1, one end of the 1st strip line 1 is used for an input terminal of a microwave signal RF, one end of the 2nd strip line 2 connects to ground to be a short-circuit end and other ends of both the strip lines 1, 2 are interconnected by the 3rd strip line 3 whose line width is W3. Thus, the excellent resonance characteristic is kept to make the configuration small. The resonator is useful a microwave filter, a duplexer, and a power supply line for a power amplifier requiring a line of a low loss or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stripline resonator, and more particularly to a stripline resonator which can be made compact.

[0002]

2. Description of the Related Art FIG. 7 is a perspective view showing an example of a conventional stripline resonator. This stripline resonator 500 has a dielectric body (relative permittivity εr) of a dielectric substrate D1 whose upper and lower surfaces are shielded by ground conductor surfaces G1 and G2.
This is a structure in which a stripline resonator body 50 is provided.
H is a via hole. As shown in FIG. 8, in the stripline resonator main body 50, the first stripline 1 and the second stripline 2 having a line width W1 and a line length L51 are arranged side by side with a line gap distance s ′ larger than the line width W1. They are arranged substantially in parallel, one end of the first strip line 1 is used as an input end of the microwave signal RF, one end of the second strip line 2 is grounded to be a short-circuit end, and the other ends of both strip lines 1 and 2 are line widths. In this configuration, the third strip lines 53 of W3 are connected to each other.

For example, a desired resonance frequency f1 = 1.6G
Hz (wavelength λo = 188 mm), relative permittivity εr = 6.1
, The effective wavelength λg = λo / √ {εr} = 76m
m. If the resonator length is 1/8 of the effective wavelength λg,
The resonator length is 9.5 mm. To give an example of the dimensions of the stripline resonator body 50, the line width W1 = W3 = 0.6 mm to 0.8 mm, the length L51 =
2.8 mm to 3.2 mm, spacing s' = 1.9 mm to 2.
It will be 3 mm.

[0004]

In the conventional stripline resonator 500 described above, the first stripline 1 and the second stripline 2 are formed in order to suppress unnecessary electromagnetic coupling between the first stripline 1 and the second stripline 2. The line gap distance s ′ of the line 2 is set larger than the line width W1. However, if the line gap distance s'is increased,
Since the area occupied by the portion between the first strip line 1 and the second strip line 2 becomes large, there is a problem that the strip line resonator 500 becomes large. Then, the objective of this invention is providing the stripline resonator which can be comprised small.

[0005]

In a stripline resonator of the present invention, a first stripline and a second stripline having a predetermined line width and line length are arranged substantially parallel to each other,
A stripline resonator in which one end of a first stripline is an input end, one end of a second stripline is grounded to be a short-circuited end, and the other ends of both striplines are connected to each other by a connecting conductor Line and second
The line gap distance of the strip line is 1 of the line width.
The characteristic feature of the configuration is that it is / 3 or less.

[0006]

In the stripline resonator of the present invention, the line gap distance between the first stripline and the second stripline is 1/3 or less of the line width. The inventors of the present invention have conducted extensive studies and found that, with such a structure, the electromagnetic coupling between the first strip line and the second strip line does not adversely affect the characteristics of the resonator. , Rather found to have a positive impact. That is, it was found that the no-load Q becomes high. It was also found that the resonator length can be shortened. Thus, in order to reduce the line gap distance, the first strip line and the second strip line
The area occupied by the part between the strip lines becomes smaller,
The stripline resonator can be made compact. Also, the characteristics as a resonator are improved.

The reason why the resonator length can be shortened is considered as follows. Considering the distribution of the electric field energy and the magnetic field energy included in the stripline resonator, the electric field energy is biased toward the input end side and the magnetic field energy is biased toward the short circuit end side. This means that the resonator length can be shortened by increasing the input capacitance. On the other hand, in the stripline resonator of the present invention, since the line gap distance is reduced and electromagnetic coupling is increased, the input capacitance is increased.
Therefore, the resonator length can be shortened. The first
If the line gap distance between the strip line and the second strip line is larger than 1/3 of the line width, a sufficient size reduction effect cannot be obtained.

[0008]

EXAMPLES The present invention will be described in more detail with reference to the examples shown in the drawings. The present invention is not limited to this.

First Embodiment FIG. 1 is a perspective view of a stripline resonator according to the first embodiment of the present invention. This stripline resonator 100
Is a structure in which the stripline resonator body 10 is provided in the dielectric (relative permittivity εr) of the dielectric substrate D1 whose upper and lower surfaces are shielded by the ground conductor surfaces G1 and G2. H is a via hole. As the dielectric of the dielectric substrate D1, it is preferable to use a material having a small dielectric loss tangent (barium oxide, alumina oxide, silicon oxide, Teflon, etc.). As the conductor material of the strip lines 1 and 2,
It is preferable to use a material having a low specific resistance (silver, copper, etc.).

As shown in FIG. 2, the stripline resonator body 10 has a first line width W1 and a line length L1.
The strip line 1 and the second strip line 2 are arranged side by side in parallel with each other at a line gap distance s of 1/3 or less of the line width W1, and one end of the first strip line 1 is used as an input end of the microwave signal RF. One end of the second strip line 2 is grounded to be a short-circuit end, and both strip lines 1 and 2 are connected.
The other ends are connected to each other by a third strip line 3 having a line width W3.

For example, a desired resonance frequency f1 = 1.6G
Hz (wavelength λo = 188 mm), relative permittivity εr = 6.1
Then, the resonator length is about 8.5 mm. To give an example of the dimensions of the stripline resonator body 10 for this, the line width W1 = W3 = 0.6 mm to 0.8 mm,
Length L1 = 3.1 mm to 3.7 mm, interval s = 0.15
It becomes mm-0.25 mm.

Stripline resonator 100 of the present invention
(W1, W3 = 0.69 mm, L1 = 3.7 mm, s =
0.2 mm, εr = 6.1, tan δ = 0.002) and the conventional stripline resonator 500 (W1, W3 =
0.69 mm, L1 = 2.5 mm, s = 2.0 mm, ε
r = 6.1, tan δ = 0.002) and the unloaded Q is f1
= 1.6 GHz, the stripline resonator 100 of the present invention improved the unloaded Q by about 20 compared to the conventional stripline resonator 500.

-Modified First Embodiment- The above first embodiment may be modified as follows. As in the stripline resonator body 10a shown in FIG. 3, the bend portion may be rectangular. As in the stripline resonator body 10b shown in FIG. 4, the bend portion may have a round shape.

-Second Embodiment- FIG. 5 is a perspective view of a stripline resonator according to a second embodiment of the present invention. This stripline resonator 200
Is a structure in which the stripline resonator body 20 is provided in the dielectric (relative permittivity εr) of the dielectric substrate D1 whose upper and lower surfaces are shielded by the ground conductor surfaces G1 and G2. H is a via hole.

As shown in FIG. 2, the stripline resonator body 20 has a first line width W1 and a line length L1.
The strip line 21 and the second strip line 22 are arranged substantially parallel to each other so as to be vertically overlapped with each other at a line gap distance s of 1/3 or less of the line width W1.
Is used as an input end of the microwave signal RF, one end of the second strip line 2 is grounded to be a short-circuit end, and the other ends of both strip lines 1 and 2 are connected to each other by a via hole 23. According to the stripline resonator 200 of the second embodiment, since the striplines 21 and 22 are arranged so as to be vertically stacked, the occupied area can be reduced.

[0016]

According to the stripline resonator of the present invention, it is possible to maintain good resonance characteristics and reduce the size of the structure. It is useful for microwave filters, duplexers, power amplifier power lines that require low-loss lines, etc.

[Brief description of drawings]

FIG. 1 is a perspective view showing a stripline resonator according to a first embodiment of the present invention.

FIG. 2 is a pattern diagram of the stripline resonator main body in FIG.

FIG. 3 is a pattern diagram of a stripline resonator body of a modified example of the first embodiment.

FIG. 4 is a pattern diagram of a stripline resonator body according to another modification of the first embodiment.

FIG. 5 is a perspective view showing a stripline resonator according to a second embodiment of the present invention.

6 is a perspective view of the stripline resonator main body in FIG.

FIG. 7 is a perspective view showing an example of a conventional stripline resonator.

8 is a pattern diagram of the stripline resonator main body in FIG.

[Explanation of symbols]

100, 200, 500 Stripline resonator 10, 10a, 10b, 20, 50 Stripline resonator body 1, 21 1st stripline 2, 22 2nd stripline 3 3rd stripline 23, H Via hole G1, G2 Ground Conductor surface D1 Dielectric substrate RF, RF 'Microwave signal

Claims (1)

[Claims] 1. A first strip line and a second strip line having a predetermined line width and line length are arranged substantially parallel to each other, and one end of the first strip line is used as an input end and one end of the second strip line is grounded. In the stripline resonator in which the other ends of both striplines are connected to each other by a connecting conductor, the line gap distance between the first stripline and the second stripline is 1/3 of the line width. A stripline resonator characterized by the following.