JP2754606B2 - Method and apparatus for evaluating high frequency device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency device evaluation apparatus, and more particularly to evaluation of a high-frequency device in a high frequency band such as a microwave band.

[Conventional technology]

FIG. 3 is a perspective view showing an example of a conventional high-frequency element evaluation device. In the figure, (1) is a package incorporating a high-frequency device to be measured. A lead wire (4) protrudes from the package (1), and the lead wire (4) is connected to a high-frequency element inside the package (1). (6)
Is a ground conductor, and the back surface of the dielectric substrate (2) is grounded. (3) is a signal line provided on the dielectric substrate (2). Reference numeral (5) denotes a press-contact rod for pressing the lead wire (4) to bring the lead wire (4) into contact with the signal line (3).

Next, the operation will be described. Generally, when handling microwave band high frequency signals, the signal line (3) functions as a distributed constant line. In FIG. 3, the ground conductor (6) and the signal line (3) constitute a microstrip line,
Assuming that the dielectric constant of the dielectric substrate (2) is ε, the substrate thickness is d, and the line width of the signal line (3) is W, the characteristic impedance Z0 of the signal line (3) is Z0 (ε, d, W). This is a function of three variables. In order to evaluate a high-frequency element, it is necessary to set a desired characteristic impedance (generally 50Ω) so that unnecessary reflection of a high-frequency signal does not occur.

On the other hand, since an insulating material such as Teflon is used as the material of the pressure welding rod (5), the dielectric constant ε _A of the pressure welding rod (5) is different from the dielectric constant ε _O of air, so that the pressure welding rod (5) is used to hold down. in part (referred to or larger than the first portion) of its dependent signal line (3), the characteristic impedance _{Z1 = Z1 (ε, ε a} ≠ ε O, d, W) ≠ Z0 (ε, d, W) , and the second The mismatch of the characteristic impedance of the portion 1 causes unnecessary reflection of the high-frequency signal.

[Problems to be solved by the invention]

Since the conventional high-frequency device evaluation device is configured as described above, the characteristic impedance mismatch of the signal line occurs just below the pressure contact rod that presses the lead wire of the package and contacts the signal line on the dielectric substrate, Since unnecessary reflection of high-frequency signals occurs, accurate evaluation of high-frequency elements cannot be performed, which causes a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to match the characteristic impedance immediately below a pressure contact rod and eliminate unnecessary reflection of a high-frequency signal.

[Means for solving the problem]

A high-frequency device evaluation apparatus according to the present invention includes a signal line formed on a dielectric substrate by defining a signal line width and a dielectric substrate thickness to have a desired characteristic impedance, and a lead wire of a package incorporating the high-frequency device, In a high-frequency element evaluation device that evaluates a high-frequency element by pressing and contacting with a pressure contact rod that is an insulator, a signal line includes a first portion immediately below the pressure contact rod and a second portion other than the first portion. The first part has a first part when pressed with a pressure rod.
The characteristic impedance of the first part and the characteristic impedance of the second part are different except that the characteristic impedance of the second part is equal to the characteristic impedance of the second part, except at the time of pressing by the pressure contact rod. is there.

Further, the characteristic impedance of the first part and the characteristic impedance of the second part are made different by changing the signal line width of the first part and the second part of the signal line.

Further, the characteristic impedance of the first portion and the characteristic impedance of the second portion are made different by changing the thickness of the dielectric substrate of the first portion and the second portion of the signal line.

Further, the method for evaluating a high-frequency element according to the present invention includes a step of preparing any one of the above-described high-frequency element evaluation apparatuses, and mounting a package containing the high-frequency element in the high-frequency element evaluation apparatus and pressing the package using a pressure contact rod. Contacting a lead wire with the first portion of the signal line, and evaluating the high-frequency element.

[Action]

In the high-frequency element evaluation device according to the present invention, the signal line has a first portion immediately below the pressure contact bar and a second portion other than the first portion, and when the first portion is pressed by the pressure contact bar. First
Since the characteristic impedance of the first part and the characteristic impedance of the second part are made different from each other so that the characteristic impedance of the part and the characteristic impedance of the second part become equal except for the pressing by the press-contact rod, No unnecessary reflection of a high-frequency signal occurs during the evaluation of the device.

Further, since the method for evaluating a high-frequency element according to the present invention includes the step of preparing the above-described high-frequency element evaluation apparatus and the step of evaluating the high-frequency element by the high-frequency element evaluation apparatus,
There is no unnecessary reflection of high-frequency signals when evaluating high-frequency elements.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a high-frequency device evaluation apparatus according to one embodiment of the present invention. In the figure, (1) to (6) are the third
The description is omitted because it is equivalent to that shown in the conventional example of FIG. (7) is a signal line in consideration of the dielectric constant of the pressure welding rod (5).

Next, the operation will be described. When the line width of the signal line (7) is W and ', and the line width of the signal line (3) is W, Z1 (ε, ε _A , d, W ′) = Z _O (ε, d, W) W ′ is determined so that

Here, d and ε are the substrate thickness and dielectric constant of the dielectric substrate (2), Z1 is the characteristic impedance immediately below the pressure welding rod (5), and ZO is the characteristic impedance of other parts.

Since the equation (1) is used, the characteristic impedance is
The same applies to any part of the signal line (3) and the signal line (7) in consideration of the permittivity of the press-connecting rod, unnecessary reflection of high-frequency signals does not occur, and accurate high-frequency element evaluation can be performed.

In the above embodiment, the characteristic impedance is matched at the signal line (3), but may be adjusted at the dielectric substrate (2).

FIG. 2 shows another embodiment of the present invention and is a perspective view showing a high-frequency device evaluation apparatus. In the figure, (1) ~
(6) is equivalent to that shown in FIG. (8) is a dielectric substrate in consideration of the dielectric constant of the pressure rod (5), 'when _{a, Z 1 (ε, ε A} , d' the thickness _{d, W) = Z O (} ε , d, W)... d ′ is determined as follows.

Here, ε, d, W, Z0, and Z1 represent the same variables as in equation (1).

Because of the equation (2), the characteristic impedance is
The same applies to any part of the signal line (3), and unnecessary high-frequency signal reflection does not occur, and accurate high-frequency element evaluation can be performed.

〔The invention's effect〕

As described above, in the high-frequency element evaluation device according to the present invention, the signal line has the first portion immediately below the pressure contact bar and the second portion other than the first portion, and the first portion is a pressure contact rod. The characteristic impedance of the first part and the characteristic impedance of the second part are set so that the characteristic impedance of the first part and the characteristic impedance of the second part become equal when pressed. Therefore, unnecessary reflection of a high-frequency signal does not occur during the evaluation of the high-frequency element, and the method for evaluating the high-frequency element according to the present invention includes the steps of preparing the above-described high-frequency element evaluation apparatus; And the step of evaluating the high-frequency element by the method described above. Therefore, there is an effect that unnecessary high-frequency signal reflection is not caused in the evaluation of the high-frequency element and accurate high-frequency element evaluation can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a high-frequency device evaluation device according to one embodiment of the present invention, FIG. 2 is a perspective view showing a high-frequency device evaluation device according to another embodiment of the present invention, and FIG. It is a perspective view which shows an element evaluation apparatus. In the figure, (1) is a package, (2) is a dielectric substrate, (3) is a signal line, (4) is a lead wire, (5) is a press-contact rod, (6) is a ground conductor, and (7) is a press-contact. A signal line taking into account the permittivity of the rod, and (8) is a dielectric substrate taking into account the permittivity of the pressure contact rod. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (4)

(57) [Claims] A signal line formed on a dielectric substrate by defining a signal line width and a dielectric substrate thickness to obtain a desired characteristic impedance, and a lead wire of a package containing a high-frequency element are pressure-welded as an insulator. In the high-frequency device evaluation apparatus for evaluating the high-frequency device by pressing and contacting with a rod, the signal line has a first portion directly below the press-contact bar and a second portion other than the first portion. Then, the first portion except for the pressing by the press-contact bar is set so that the characteristic impedance of the first portion is equal to the characteristic impedance of the second portion when the first portion is pressed by the press-contact bar. The characteristic impedance of the portion is different from the characteristic impedance of the second portion. 2. The characteristic impedance of the first part and the characteristic impedance of the second part are changed by changing the signal line width of the first part and the second part of the signal line. The high-frequency element evaluation device according to claim 1. 3. The characteristic impedance of the first part and the characteristic impedance of the second part are changed by changing the thickness of the dielectric substrate of the first part and the second part of the signal line. The high-frequency element evaluation device according to claim 1, wherein 4. A step of preparing the high-frequency device evaluation device according to claim 1, wherein a package containing a high-frequency device is mounted on the high-frequency device evaluation device, and a pressing rod is used. And pressing the lead wire into contact with the first portion of the signal line to evaluate the high-frequency element.