JPH06104612A - Microstrip bend - Google Patents

Abstract

PURPOSE:To provide the small sized microstrip bend with excellent reflection loss over a wide band. CONSTITUTION:The bent consists of a 1st microstrip line 11, a 3rd microstrip line 13 whose propagation direction differs from the 1st microstrip line 11 by 45 deg., and a 2nd microstrip line 12 whose propagation direction differs from the 1st microstrip line 11 by 90 deg. and from the 3rd microstrip line 13 by 45 deg., the 1st microstrip line 11 and the 2nd microstrip line 12 are input and output lines whose characteristic impedance is Zo (usually 50ohms) and whose line width is Wo, the line width W1 of the 3rd microstrip line 13 is selected to satisfy the relation of 0.7<W1/W0<0.9, and a length L equivalent to 1/sq. rt. 2 of a longer line length L1 of the 3rd microstrip line 13 is selected to satisfy the relation of 1.0<L/W0/1.6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microstrip bend which is composed of a strip line or a microstrip line and which changes its traveling direction by 90 degrees, and more particularly,
The present invention relates to a microstrip bend having a small size and a wide use frequency.

[0002]

2. Description of the Related Art A microstrip line has a traveling direction of 9
A 90 degree microstrip bend is often used when it is desired to turn and bend at 0 degrees.

FIG. 2 shows a microstrip bend according to a conventional example, in which a crossing line portion 23 where a microstrip line 21 (line width W0) and a microstrip line 22 (line width W0) having different 90 ° traveling directions intersect each other is dimensioned. The corners of the size C are cut off at an angle of 45 degrees. Then, by appropriately selecting the shape of the corner portion defined by X = C ÷ W0 (0.0 <X <2.0) with respect to the operating frequency, the characteristic of the reflection loss between the terminals 24 and 25 is very small. can get.

FIG. 3 shows a conventional microstrip bend using a 90-degree arc. The microstrip line 31 (line width W0) and the microstrip line 32 (line width W0) having different 90-degree traveling directions are line width W0.
Are connected through an arc-shaped microstrip line 33 having an inner diameter R. The larger the inner diameter R and the gentler the arc bend, the higher the operating frequency becomes.
The characteristic that the reflection loss between the terminal 35 and the terminal 35 is very small is obtained.

[0005]

In the conventional example of FIG. 2 described above, the bandwidth of the used frequency is narrow and it is difficult to reduce the reflection loss in a wide band from a low frequency to a high frequency.

Further, in the conventional example of FIG. 3, if the inner diameter R is increased, a very wide band characteristic can be obtained, but if the inner diameter R is increased, the size of the entire microstrip bend is increased.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a microstrip bend having a small size and a wide operating frequency range from low to high, eliminating the drawbacks of the conventional example. To aim.

[0008]

In order to solve the above-mentioned problems, a microstrip bend of the present invention comprises a first microstrip line and a second microstrip line which are different from each other by 45 degrees in the traveling direction. And a third microstrip line whose traveling direction differs by 90 degrees with respect to the first microstrip line and 45 degrees traveling direction with respect to the second microstrip line. The first microstrip line and the third microstrip line are input / output lines having a characteristic impedance Z ₀ (usually 50Ω) and a line width W ₀ , and the line width W ₁ of the second microstrip line is Select 0.7 <W1 / W0 <0.9, and set 1 of the longer line length L1 of the second microstrip line.
The dimension L corresponding to / √2 is selected as 1.0 <L / W0 <1.6.

[0009]

According to the present invention, a microstrip bend having a small size and a wide use frequency range from a low frequency band to a high frequency band can be realized by the above-mentioned structure.

[0010]

FIG. 1 shows a microstrip bend according to an embodiment of the present invention, which is provided between a microstrip line 11 (line width W0) and a microstrip line 12 (line width W0) having different 90 ° traveling directions. Is provided with microstrip lines 11 and 12 each having a different traveling direction at an angle of 45 degrees with respect to the microstrip line 11 and the microstrip line 12.

The line width W1 of the microstrip line 13 is
Selected as 0.7 <W1 / W0 <0.9. Dimension L corresponding to 1 / √2 of the longer line length L1 of the microstrip line 13
Is selected as 1.0 <L / W0 <1.6. And W1 / W
By appropriately selecting 0 and L / W0 with respect to the used frequency, a characteristic that the reflection loss between the terminals 14 and 15 is very small can be obtained in a wide band.

In the embodiment shown in FIG. 1, a microstrip line 11 and a microstrip line 12 are provided between a microstrip line 11 (line width W0) and a microstrip line 12 (line width W0) which are different in 90 ° traveling direction. On the other hand, by providing third microstrip lines 13 having different traveling directions at angles of 45 degrees and setting the line width and line length of the microstrip lines 13 within a certain range, excellent characteristics of reflection loss can be obtained. Obtained in a wide band.

For example, when a microstrip bend is constructed using a Teflon glass cloth type dielectric substrate having a relative dielectric constant of 2.69 and a thickness of 0.6 mm, the characteristic impedance is 50
Ω line width W ₀ = 1.60 mm, W1 ≈ 1.4 mm (W1 / W0
≈0.88) and L = 2.1mm (L / W0≈1.31),
From DC to 20 GHz, good characteristics with reflection loss between the terminals 14 and 15 of -22 dB or less are obtained.

[0014]

As described above, according to the present invention, the microstrip lines 11 (line width W different in 90 ° traveling direction) are provided.
0) and the microstrip line 12 (line width W0), the microstrip line 11 and the third microstrip line 13 having different traveling directions at angles of 45 degrees with respect to the microstrip line 12 are provided. By setting the line width and line length of the microstrip line 13 within a certain range, excellent characteristics of reflection loss can be obtained in a wide band.

[Brief description of drawings]

FIG. 1 is a pattern diagram showing a microstrip bend formed of a microstrip line according to an embodiment of the present invention.

FIG. 2 is a pattern diagram of a microstrip bend configured by a conventional microstrip line.

FIG. 3 is a pattern diagram of a microstrip bend configured by a conventional microstrip line and using an arc.

[Explanation of symbols]

 11,12,13 Microstrip line 14,15 terminals

Claims (1)

[Claims] 1. A first microstrip line, a second microstrip line whose traveling direction differs by 45 degrees with respect to the first microstrip line, and 90 degrees with respect to the first microstrip line. The traveling direction is different, and the direction is 45 degrees with respect to the second microstrip line.
An input / output line having a characteristic impedance Z ₀ (usually 50Ω) and a line width W ₀ . And the line width W1 of the second microstrip line is 0.7 <W1
/W0<0.9, and the dimension L corresponding to 1 / √2 of the longer line length L1 of the second microstrip line is 1.0 <
A microstrip bend characterized by having L / W0 <1.6.