JPS59111403A - High frequency circuit - Google Patents

Abstract

PURPOSE:To make the matching work between prestage and poststage elements easy by providing a hole-shaped circuit-missing part at an intermediate part of a conductor connecting the prestage circuit element and the poststage circuit element. CONSTITUTION:An input terminal 2 and an output terminal 3 are provided to a board 1 via connecting conductors 5, 5 and an FET15. The connecting conductor 5 is provided with a matching stub 7, and the hole-shaped circuit-missing part 8 is formed to a part by means of an etching means. A length L2 of the stub 7 from its root 7a to the circuit-missing part 8 is matched to the electric characteristic of the 2nd priority of a circuit element of the poststage side scheduled for its use and set to a location attaining the matching state as to the element. In using a different kind as the FET15 or capacitors 13, 14, the circuit-missing part 8 of the stub 7 is cut off by a knife or the like. Thus, the matching work is attained easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high frequency circuit that handles signals such as UHF or 8HF, and specifically relates to a high frequency circuit that matches circuit elements connected in series. It is.

In this type of high-frequency circuit, one end of the stub is connected to a connecting conductor that connects a circuit element on the front side and a circuit element on the rear side, and a spare conductor is provided at the tip of the stub. It is known that the stub and the spare conductor are connected with bonding wires to achieve matching according to the characteristics of the circuit elements on the subsequent stage side as needed.

However, such a structure has the drawback that the troublesome work of soldering with a soldering iron is required to connect the bonding wires, and the workability is poor.

Therefore, the present invention has been devised to eliminate the above-mentioned drawbacks.
It is an object of the present invention to provide a high frequency circuit which can achieve good matching even when circuit elements having different characteristics are used in the subsequent stage, and which can be easily matched.

The drawings showing the embodiments of the present application will be described below.

Reference numeral 1 denotes a substrate, which is made of a low-loss dielectric material (insulator material). Moreover, this is made of a relatively soft material (teflon, for example) that is relatively soft (to the extent that it will dent when touched with a knife), and is formed to have a thickness of, for example, 0.05 mm. 2 is an input end, to which a waveguide-coaxial converter is connected. 3 is an output end, to which the next stage amplifier, co/bark, etc. are connected. 4.4... indicates a connection part. Reference numerals 5, 5, . . . are connecting conductors, which connect the connecting portions 4 to each other and the connecting portions 4 to the input end 2 and the output end 3, respectively. Reference numeral 7 denotes a matching stub, the base portion 7a of which is connected to the intermediate portion of the connecting conductor 5. The width and length L of this stub 7
As is well known, l is determined so as to achieve impedance matching and noise matching between the front and rear stages of the location where the stub 7 is provided, and is, for example, 1.7.
It is set at around 3;m, around 3°73Wl1. Further, the connection location of the base portion 7a to the connection conductor 5 is determined in the same manner.

8 is a missing portion of the thank you note, which is formed by removing a portion of the stub 7 by etching means. Its shape may be an elliptical hole in addition to the square hole shown in the figure. The formation location is the original part 7.
A location where the length L2 from a to the position of the missing portion 8 is compatible with the electrical characteristics of the second order circuit element that is planned to be used as a subsequent circuit element, and a matching state can be achieved for that element (that location). is determined, for example, by experiment). In this example, Ll = 2.23 m. Also, the dimension of the missing portion 8 is a == 7. , l 3
tytSb =, 0.2311M. 9. lO
denotes a power supply end, and 11°ν denotes a microwave blocking coil. Note that the above symbols 2, 3, 4, 5, 7,
The members indicated by 9, 10, 11, and 12 are formed (for example, by printed wiring means) of copper foil (its thickness is, for example, /IPm) adhered to one surface of the substrate 1. Next, u,
14 is a capacitor connected to the connecting portion 4, which is used to block direct current and pass microwaves. b is an FET illustrated as an amplifying element, 16 is a gate, 17 is a drain, and these terminals are connected to a connection part.

Nagi is a ground conductor and is attached to the entire back surface of the board 1.

In the above configuration, when a DC power source is connected to the power supply terminals 9 and 10, the DC power is supplied to the coils u and 12.
The signal is supplied to the FET1fi through the FET1fi, and the FET1fi performs an amplification operation. Then, the microwave signal (for example, GHz) inputted from the input terminal 2 is inputted to the gate of the FET via the connecting conductor 5, the capacitor, and the connecting conductor 5, and is amplified. The amplified microwave is outputted from the drain 17 and outputted from the output end 3 via the connecting conductor 5, the capacitor 14, and the connecting conductor 5. In this case, the presence of the stub 7 allows the matching between the capacitor and the FET 15 and the FE
The matching between T15 and the capacitor 14 is good 1, so the microwave is efficiently transmitted. In this specification, when the stub 7 on the left side of FIG. 1 is viewed as the center, the capacitor 5 is referred to as the front-stage circuit element, and the FET 5 is referred to as the rear-stage circuit element, and when the stub 7 on the right side is viewed as the center, the FET 15 is referred to as the front-stage circuit element. is called a front-stage circuit element, and the capacitor 14 is called a rear-stage circuit element.

Next, when different types of FET 1fi or capacitors 13 and 14 are used, the tip of the stub 7 is cut off at the stub mark so that a matching state can be obtained for the elements to be used. Although this separation may be performed in any manner, it is preferable to perform it as follows.

That is, first, the tip 20a of the knife 20 is applied to the missing portion 8, and the knife is slid in the direction of the arrow X to cut the edge 8&. Next, apply the tip 201k of the knife to the missing portion 8 in the opposite direction to the previous one, slide the tip of the knife in the direction of arrow Y7, and cut the edge 8b. This makes systub 7 J, 4.7
In the state shown in the figure, the length L2 portion comes to act as a stub for alignment. In the case of the above-mentioned cutting, if the substrate 1 is somewhat soft, the surface of the substrate 1 will be depressed by the knife tip 20a, so that the cutting can be easily performed by sliding the knife.

Next, FIG. g of the drawing showing a different embodiment of the present application will be explained. This figure shows an example in which two cutouts 80 are provided. In such a case, when adjusting the length as described above, it is sufficient to cut the cutout portion 8e on the side that matches the characteristics of the subsequent stage circuit element. The number of the missing portions 8e may be increased. In this case or in two cases, if the type of circuit element to be used as a subsequent stage circuit element is known in advance, it is only necessary to set the positions at positions where matching can be achieved individually for each of them. If this is not the case, it is preferable to arrange them at predetermined intervals so as to be compatible with any type of subsequent circuit elements.

It should be noted that parts that are considered to have the same or equivalent structure as those in the previous figure in terms of function are given the same reference numerals as in the previous figure with the letter e, and redundant explanations are omitted.

As described above, in the present invention, the front-stage circuit element and the rear-stage circuit element are respectively arranged on the board 1, and are connected by the connecting conductor 5 attached to the surface of the board 1, and furthermore, the above-mentioned connecting conductor 5, the base part 7a of the matching stub 7 attached to the surface of the board is connected. When transmitting, both circuit elements can be matched by the stub 7, which has the effect of efficiently transmitting the high frequency signal.

Moreover, in this invention, in addition to the above configuration, the intermediate portion of the stub 7 is provided with a l or 2 for indicating the separation position.
The above thank you note missing part 8 is provided, and its position is as follows.
The length Ll from the base portion 7a to the tip portion 7b and the base portion 7
A position where the degree of difference in the electrical characteristics of the stub due to the difference in the length L2 from a to the missing portion 8 corresponds to the degree of difference in the electrical characteristics of the latter circuit element due to the difference in type. Therefore, it has the effect of (a) above. ←) When using circuit elements with different n-temperature characteristics as the subsequent circuit elements, the stub 7 has the effect of By separating the parts, matching conditions as described in (a) above can be obtained for the subsequent circuit elements used, and there is flexibility to deal with various elements.

(c) Moreover, when the above-mentioned separation is performed, the above-mentioned missing part 8
However, it is only necessary to cut the small portions sa and Bb remaining on both edges of the missing portion 8, which makes the work easier.

) Moreover, since it is the above letter of appreciation, at the time of cutting, seventhly,
After applying the tip 20& of the knife to the missing part 8, move the knife to cut one edge 8a, and then apply the tip of the knife again to the missing part in the opposite direction from the previous time. It has the advantage that the other edge 8b can be cut by moving the knife in the opposite direction to the previous cut.

This has the effect of preventing the knife from shifting during cutting and cutting an area that should not be cut, allowing the user to cut a predetermined area with high precision, and also allows damage to the board 1 to be distributed over two areas. Each has the effect of making it smaller.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and FIG. 7 is a plan view of the microwave amplifier, FIG. 2 is a partial perspective view of the vicinity of the stub, and FIG. 5 and 6 are respectively a perspective view and a plan view showing the state after cutting, FIG. 7 is a sectional view taken along the line v■-■, and FIG. 1 is a plan view showing a different embodiment. ... Board, 5... Connection conductor, 7... Stub,
8... Missing part. Figure 1 zabe Figure 2 a 7g Figure 3 Figure 4 Figure 6 Figure 5 4 be

Claims (1)

[Claims] A front-stage circuit element and a rear-stage circuit element are respectively arranged on the board, and they are connected by a connecting conductor attached to the surface of the board, and a matching conductor attached to the surface of the board is located in the middle of the connecting conductor. In a high-frequency circuit connecting the bases of the stubs, the middle part of the stub is provided with two or more thank-you note missing parts for indicating the disconnection position, and the positions thereof are different from the base part. The degree of difference in the electrical characteristics of the stub due to the difference in length to the tip and the length from the base to the missing portion is the same as the degree of difference in the electrical characteristics of the latter circuit element due to the difference in type. A high frequency circuit characterized in that the high frequency circuit is set at a position where a corresponding value is obtained.