JP2000261209A - Variable attenuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the replacing work of interchangeable parts for adjustment to easily switch the extent of attenuation and to prevent a circuit from being made large-sized. SOLUTION: This π-type attenuator consists of a main line 3 formed on a dielectric substrate 1, two branch lines 4 and 7 which have front ends opened, pads 5 and 8 which are grounded by through holes 6 and 9 provided in positions facing respective open ends, film resistances 10 and 11 provided between branch lines 4 and 7 and pads 5 and 8, and a film resistance 12 provided in the main line 3. Jumper wires 13 are arranged for film resistances so that the extent of attenuation can be switched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable attenuator which is applied to a microwave band and a millimeter wave band to easily switch an amount of attenuation.

[0002]

2. Description of the Related Art FIG. 7 is a top perspective view of a conventional variable attenuator. In the figure, 1 is a dielectric substrate, 2 is a ground conductor, 3
Is a main line, 4 is a first branch line, 6 is a first through hole, 7 is a second branch line, 9 is a second through hole,
0 is the first film resistance, 11 is the second film resistance, 12 is the third film resistance, 13 is the jumper wire, 17a, 17b and 17
c is a replaceable attenuator, 18a, 18b and 18c are carriers, and 19 is a screw.

Next, the operation will be described. This variable attenuator is provided to adjust the overall output power in the module. The adjustment is a mechanism in which a plurality of attenuators of replacement parts for adjustment having different attenuation amounts are prepared, and a desired attenuation amount is obtained by replacing the attenuator to be used. The replaceable attenuators 17a, 17b and 17c used are a first film resistor 10 having one end grounded through a first through hole 6 and a second film resistor 11 having one end grounded through a second through hole 9. And the third provided in the main line 3
Π-type attenuator constituted by the film resistor 12 of FIG. First, as shown in (a), a replacement part type attenuator 17a is attached to a carrier 18a, fixed at a predetermined position in a module with a screw 19, and connected to a line on both sides by a jumper line 13. Next, the output power of the module is measured in this state, and it is confirmed whether the output power is a desired value. At this time, if a desired power value cannot be obtained, it is necessary to change the amount of attenuation of the attenuator. Therefore, the carrier 18a to which the replacement part-type attenuator 17a is attached is removed and replaced with a carrier 18b to which the replacement part-type attenuator 17b having a different attenuation as shown in FIG.
Then, the output power of the module is measured again to confirm whether the output power is the desired power value. Thereafter, replacement is performed in the same manner.

[0004]

The conventional variable attenuator is
With the above-described configuration, it is necessary to replace the replacement part-type attenuator at the time of adjustment, and there has been a problem that the work of removal and attachment occurs.

[0005]

Means for Solving the Problems In the first invention,
A dielectric substrate, a ground conductor provided on one surface of the dielectric substrate, a main line provided on the other surface of the dielectric substrate, and a first open end connected in parallel to the main line. A branch line, a first pad provided at a position facing the front end of the first branch line and connected to the ground conductor by a first through hole, and an open end connected in parallel to the main line. A second branch line, a second pad provided at a position facing the tip of the second branch line and connected to the ground conductor by a second through hole, formed in the first branch line. A first film resistance provided in the second branch line; a second film resistance formed in the second branch line; and a main film line between the first branch line and the second branch line. A third film resistor formed and provided, and a jumper wire for jumping the third film resistor, Wherein the distal end of the serial first branch line first
And between the second pad and the tip of the second branch line and the second pad can be connected by a jumper wire.

In the second invention, the dielectric substrate, a ground conductor provided on one surface of the dielectric substrate, a main line provided on the other surface of the dielectric substrate, A first branch line having an open end connected in parallel to the first branch line, a first open stub provided at a position facing the end of the first branch line and having a length of 1/4 wavelength at a center frequency; A second branch line with an open end connected in parallel to the line, a second open stub provided at a position facing the end of the second branch line and having a length of 1/4 wavelength at a center frequency; A first film resistor formed and provided in the first branch line; a second film resistor formed and provided in the second branch line;
A third film resistor formed and provided in the main line between the first and second branch lines, and a jumper wire for jumping the third film resistance, wherein a tip of the first branch line and the first The configuration is such that jumpers can be connected between the pads and between the tip of the second branch line and the second pad.

Further, in the third invention, a plurality of attenuations can be obtained by cascading the variable attenuators according to the first invention or the second invention.

According to a fourth aspect of the present invention, in the variable attenuator according to the first or second aspect, each of the first, second, and third film resistors is provided. Is N series film resistors,
The configuration is such that a plurality of attenuations can be obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a top perspective view of Embodiment 1 of the present invention. In the figure, 5 is a first pad, and 8 is a second pad. FIG.
FIG. 2 is an equivalent circuit diagram of the first embodiment of the present invention.

Next, the operation will be described. This variable attenuator has a state in which a third film resistor 12 is connected by a jumper line 13 as shown in FIG. 1A and a state in which the jumper line 13 of the third film resistor 12 is removed as shown in FIG. And between the tip of the first branch line 4 and the first pad 5 and the second branch line 7
Jumper wires 13 between the tip of the
It switches and uses the state connected with. FIGS. 2A and 2B show equivalent circuits in each state. FIG.
In the case of (a), since the third film resistor 12 is jumpered by the jumper line 13, it is similar to the absence of the third film resistor 12.
Therefore, the attenuation amount of the entire circuit can be regarded as zero. On the other hand, in the case of FIG. 2B, the tip of the first branch line 4 is the first branch line 4.
, The tip of the second branch line 7 is grounded by the second pad 8, and the first film resistor 10, the second film resistor 11, and the third film resistor 12 have a π-type attenuation. Form a bowl. Therefore, a certain amount of attenuation determined by the resistance value of each film resistor is exhibited. Therefore, by switching the two states by connecting the jumper lines 13, an effect of configuring a variable attenuator can be obtained.

Embodiment 2 FIG. 3 is a top perspective view of Embodiment 2 of the present invention. In the figure, 14 is a first open stub whose line length is と wavelength at the center frequency, and 15 is a second open stub whose line length is １ ／ wavelength at the center frequency. Instead of having been grounded by the first pad 5 and the second pad 8 in the first embodiment, a first open stub 14 and a second open stub 15 are used, thereby achieving the same effect as in the first embodiment. The effect is obtained.

Embodiment 3 FIG. 4 is a top perspective view of Embodiment 3 of the present invention. In the figure, reference numeral 16 denotes a unit variable attenuator. This variable attenuator is used in the first embodiment.
Are cascaded as unit variable attenuators 16. Here, it is assumed that each unit variable attenuator 16 exhibits a different attenuation amount. FIG. 5 is an equivalent circuit diagram of Embodiment 3 of the present invention.

Next, the operation will be described. FIG. 4 (a),
(B) and (c) show a part when the state of the variable attenuator is switched. 5A, 5B, and 5C show equivalent circuits corresponding to each state. First,
As shown in (a), all unit variable attenuators 16a, 16b
And 16c, the third film resistors 12a, 12b,
When each of the resistors 12c is jumpered by the jumper line 13, each of the film resistors is short-circuited, which is the same as the absence thereof. Therefore, the attenuation of the entire circuit can be regarded as zero. next,
As shown in (b), the tip of the first branch line 4a is connected to the first pad 5a and the tip of the second branch line 7a is connected to the second pad 8a by a jumper line 13, respectively. , 12c are jumpered by the jumper line 13, only the unit variable attenuator 16a forms a π-type attenuator, so that the unit variable attenuator 16
The amount of attenuation represented by a is obtained. Further, as shown in (c), the tip of the first branch line 4b and the tip of the first pad 5b and the tip of the second branch line 7b and the second pad 8b are connected by the jumper wire 13, respectively, to form the third film. When each of the resistors 12a and 12c is jumpered by the jumper wire 13, only the unit variable attenuator 16b forms a π-type attenuator, so that the attenuation amount exhibited by the unit variable attenuator 16b is obtained as a whole circuit. Similarly, by switching the connection state of each unit variable attenuator, the effect of configuring a variable attenuator exhibiting an attenuation determined by a combination of the respective attenuations is obtained.

Although the case where three unit variable attenuators are connected in series has been described here, it goes without saying that the same effect can be obtained with a plurality of unit variable attenuators.

Embodiment 4 FIG. 6 is an equivalent circuit diagram of Embodiment 4 of the present invention. The variable attenuator according to the first embodiment has a configuration in which each film resistance is multi-staged in series.
Here, the first film resistors 10d and 10e are provided in series in the first branch line 4, the second film resistors 11d and 11e are provided in series in the second branch line 7, and the film resistance is provided in the main line 3. Resistors 13d and 13e are provided in series.

Next, the operation will be described. FIG. 6 (a),
(B) and (c) show equivalent circuits when the connection state is switched. First, as shown in FIG.
12e is jumpered by a jumper line 13. In this case, since it is the same as the absence of each film resistance, the attenuation of the entire circuit can be regarded as zero. Next, as shown in (b), the first film resistor 10e, the second film resistor 11e, and the third film resistor 12e are each jumpered by the jumper line 13, and the tip of the first branch line 4 and the first film resistor 4e are connected. The pad 5 and the tip of the second branch line 7 are connected to the second pad 8 by a jumper line 13, respectively. In this case, the first film resistance 1
0d, the second film resistance 11d, and the third film resistance 12d form a π-type attenuator, and an attenuation determined by these film resistances is obtained. Also, as shown in FIG.
And the second film resistance 11d and the third film resistance 12d are jumpered by jumper lines 13, respectively.
The tip of the first branch line 4 is connected to the first pad 5, and the tip of the second branch line 7 is connected to the second pad 8 by a jumper line 13. In this case, the first film resistance 10e, the second film resistance 11e, and the third film resistance 12e make π
An attenuator of the shape is formed, and an attenuation determined by these film resistances is obtained. As described above, by switching the connection state, the effect of configuring a variable attenuator exhibiting three types of attenuation can be obtained.

Here, the case where two first film resistors, second film resistors, and third film resistors are provided in series has been described. However, the same effect can be obtained with a plurality of film resistors. Needless to say.

[0018]

According to the first aspect, the dielectric substrate, the ground conductor provided on one surface of the dielectric substrate, the main line provided on the other surface of the dielectric substrate, A first branch line having an open end connected in parallel to the line, a first pad provided at a position facing the end of the first branch line and connected to the ground conductor by a first through hole; A second branch line having an open end connected in parallel to the main line, and a second branch line provided at a position facing the end of the second branch line and connected to the ground conductor by a second through hole. A first film resistance formed and provided in the first branch line, a second film resistance formed and provided in the second branch line, and the first branch line And a third film resistance formed and provided in the main line between the second branch lines;
A jumper wire for jumping the third film resistor,
Since the configuration is such that the end of the first branch line and the first pad and the end of the second branch line and the second pad can be connected by a jumper wire, replacement work of replacement parts for adjustment is performed. And the amount of attenuation can be easily switched. In addition, an effect is obtained that the circuit can be prevented from being enlarged.

According to the second aspect of the present invention, instead of the first and second pads connected to the ground conductor by the through holes used in the first aspect of the present invention, a quarter wavelength at the center frequency is used. Since the first open stub and the second open stub, which are lengths, are used, there is no need to manufacture a through hole, and an effect of easily switching the amount of attenuation without replacing the adjustment replacement part can be obtained. At the same time, the effect of shortening the manufacturing period and reducing the cost can be obtained.

According to the third aspect of the present invention, a plurality of variable attenuators constructed according to the first aspect of the present invention are provided on the same substrate, and are connected in series in multiple stages as unit variable attenuators exhibiting different amounts of attenuation. The state of each unit variable attenuator can be individually switched to combine the attenuation amounts, so that the effect of the first invention can be obtained, and the effect that a step variable attenuator can be configured can be obtained. In addition, since a plurality of types of attenuation can be obtained with the same substrate, the effect of reducing the number of assembling procedures can be obtained as compared with a case where individual attenuations are provided for a plurality of substrates.

Further, according to the fourth aspect, in the first aspect, each of the first, second and third film resistors is constituted by N series film resistors. Can be combined with each other to connect or disconnect the jumper wires, so that the effects of the first invention can be obtained, and that a plurality of types of attenuation can be obtained with one variable attenuator.

[Brief description of the drawings]

FIG. 1 is a top perspective view of Embodiment 1 of the present invention.

FIG. 2 is an equivalent circuit diagram of the first embodiment of the present invention.

FIG. 3 is a top perspective view of Embodiment 2 of the present invention.

FIG. 4 is a top perspective view of a third embodiment of the present invention.

FIG. 5 is an equivalent circuit diagram according to a third embodiment of the present invention.

FIG. 6 is an equivalent circuit diagram according to a fourth embodiment of the present invention.

FIG. 7 is a top perspective view of a conventional variable attenuator.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 dielectric substrate, 2 ground conductor, 3 main line, 4 first branch line, 5 first pad, 6 first through hole, 7 second branch line, 8 second pad, 9 second Through hole, 10 1st film resistance, 11 2nd film resistance, 12 3rd film resistance, 13 jumper wire, 14 1st open stub, 15 2nd open stub, 1
6 unit variable attenuator, 17 replacement attenuator, 18
Carrier, 19 screws.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kazuki Inami 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term within Mitsubishi Electric Corporation (reference) 5J013 AA06 5J026 AA03 BA02 BA03 5J098 AA00 AA11 AB34 AC05 AD15 EA09

Claims (4)

[Claims] 1. A dielectric substrate, a ground conductor provided on one surface of the dielectric substrate, a main line provided on the other surface of the dielectric substrate, and a tip connected in parallel to the main line. An open first branch line, a first pad provided at a position facing the tip of the first branch line and connected to the ground conductor by a first through hole, connected in parallel to the main line A second branch line having an open front end, a second pad provided at a position facing the front end of the second branch line and connected to the ground conductor by a second through hole, A first film resistance formed and provided in the branch line, a second film resistance formed and provided in the second branch line, and a first film resistance between the first branch line and the second branch line. A third film resistor formed and provided in the main line of the third embodiment, and a jumper for jumping the third film resistor. And a variable attenuator. 2. A dielectric substrate, a ground conductor provided on one surface of the dielectric substrate, a main line provided on the other surface of the dielectric substrate, and a tip connected in parallel to the main line. An open first branch line, a first open stub provided at a position facing the tip of the first branch line and having a length of 1/4 wavelength at a center frequency, connected in parallel to the main line; A second branch line having an open end, provided at a position facing the front end of the second branch line, and having a center frequency of 1/4;
A second open stub having a wavelength length, a first film resistance formed and provided in the first branch line, and a second film resistance formed and provided in the second branch line. , The first
A variable attenuator comprising: a third film resistor formed and provided in a main line between the first branch line and the second branch line; and a jumper wire for jumping the third film resistor. . 3. A variable attenuator comprising a variable attenuator according to claim 1 or 2 connected in cascade. 4. The variable attenuator according to claim 1, wherein the first film resistance, the second film resistance,
A variable attenuator, wherein each of the third film resistors is composed of N series film resistors.