JPH0328583Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention relates to a high frequency feedback amplifier that amplifies high frequency signals.

"Prior Art" In an amplifier that amplifies high frequency signals such as microwaves, a resistor used in a feedback circuit is required to have a small parallel capacitance. In other words, when a feedback resistor has a capacitance in parallel, the impedance of the feedback circuit changes depending on the frequency of the signal to be amplified, and the amplification factor has a drawback that it changes greatly depending on the frequency. For this reason, conventionally, as shown in FIG. 2, two chip resistors 1 and 2 with small parallel capacitances are connected in series.

As is well known, the chip resistors 1 and 2 have resistive elements formed in the form of a film, so that the parallel capacitance can be reduced.

However, as shown in Figure 2, by connecting the two chip resistors 1 and 2 in series, the parallel capacitance of the two chip resistors 1 and 2 is connected in series, and the overall capacitance becomes smaller. value.

In addition, as shown in FIG. 2, one of the chip resistors 1 and 2 is implanted in the output side terminal 4 of the active element 3, and the resistor 1 is connected to the other end of the implanted resistor 2.
By connecting the resistors 1 and 2 at right angles and connecting the other end of the resistor 1 to the input terminal 6 of the active element 3 through the wire 5, the distance between the resistors 1, 2 and the wire 5 and the ground conductor 7 can be reduced. It can be taken in large quantities.
Therefore, the structure is such that stray capacitance between the feedback circuit and the ground can be reduced.

In FIG. 2, numeral 8 indicates a chip type capacitor.
This chip type capacitor 8 is connected in series with resistors 1 and 2 to form a feedback circuit. Therefore, the active element 3, resistors 1 and 2, and capacitor 8 can be represented as a circuit as shown in FIG.

``Problems to be Solved by the Invention'' The conventional structure shown in FIG. 2 has the drawback of low mechanical strength because the chip components are embedded in the substrate. Another drawback is that it takes time to assemble.

"Means for solving the problem" In this invention, a plurality of resistor layers are formed on an auxiliary insulating plate, and a single feedback resistor is constructed by connecting the plurality of resistor layers in series with a capacitive element. Lead out terminals from both ends of this feedback resistor, use these terminals to install an auxiliary insulating plate vertically to the main insulating plate on which the active element is attached, and place the feedback resistor between the input and output of the active element. It is configured to connect.

According to the configuration of this invention, the parallel capacitance of the feedback resistor can be reduced by connecting a plurality of resistor layers in series.

In addition, terminals are provided at both ends of the feedback resistor, and the feedback resistor is connected between the input and output of the active element through these terminals, and the auxiliary insulating plate is installed perpendicularly to the main insulating plate. With this structure, the stray capacitance value between the feedback resistor and the ground can be reduced.

Therefore, according to this invention, since the parallel capacitance and stray capacitance of the feedback resistor can be made small, it is possible to obtain a high frequency feedback amplifier having a uniform amplification factor with respect to frequency.

Moreover, since the feedback resistor is integrally formed on the auxiliary insulating plate, assembly is easy. It is also possible to provide a high frequency feedback amplifier with strong mechanical strength.

``Example'' Figure 1 shows an example of this invention. In FIG. 1, parts corresponding to those in FIG. 2 are designated by the same reference numerals.

In FIG. 1, 11 indicates an auxiliary insulating plate. In this embodiment, two resistor layers 12 and 13 are formed on this auxiliary insulating plate 11.
Conductive layers 14 and 15 are formed between the conductive layers 13 and the chip capacitor 8 is connected through the conductive layers 14 and 15,
This shows a case where a feedback circuit is configured by connecting a resistor and a capacitor in series.

That is, conductive layers 16 and 17 are formed on both ends of the auxiliary insulating plate 11, and resistor layers 12 and 13 are formed, one end of which is in contact with the conductive layers 16 and 17, respectively. Conductive layers 14 and 15 for connecting the resistor layers 12 and 13 in series are formed at the other end of each of the resistor layers 12 and 13, and the electrodes 8A and 8B of the chip capacitor 8 are formed on the conductive layers 14 and 15. Solder the
A chip capacitor 8 is connected in series between resistor layers 12 and 13. According to this connection structure, a feedback circuit similar to the feedback circuit shown in FIG. 3 is constructed. On the other hand, in this invention, terminals 18 and 19 are attached to conductive layers 16 and 17. These terminals 18 and 19 are provided to protrude outward from one side of the auxiliary insulating plate 11. The auxiliary insulating plate 11 is coated with, for example, epoxy resin or the like, although not particularly shown, with the chip-type capacitor 8 mounted thereon, to cover it with an insulating layer.

These terminals 18 and 19 are connected to the output side terminal 4 and input side terminal 6 of the high frequency amplification active element 3 mounted on the main insulating plate.

With this configuration, the auxiliary insulating plate 11
Since the plurality of resistor layers 12 and 13 formed in the above are connected in series, parallel capacitance existed between the conductive layers 16 and 14 and 15 and 17 that connect the resistor layers 12 and 13 in series. Even if the parallel capacitance is connected in series with each other, terminals 18 and 19
The parallel capacitance can be reduced by looking between

In addition, since the terminals 18 and 19 are provided in a protruding manner, and the auxiliary insulating plate 11 is installed perpendicularly to the main insulating plate by means of these terminals 18 and 19, the connection between the resistor layers 12, 13 and the ground conductor 7 is Stray capacitance can be reduced.

"Operations and Effects of the Invention" As explained above, according to this invention, the value of the parallel capacitance of the feedback resistor can be reduced, and the stray capacitance of the feedback resistor can be reduced.

Therefore, according to the structure of this invention, the frequency characteristics of the high frequency feedback amplifier can be made to be flat amplification characteristics over a wide band.

Furthermore, since the feedback resistor is installed on the main insulating plate, the capacitance between the feedback resistor and the ground, that is, the stray capacitance, can be reduced. Therefore, this also makes it possible to flatten the gain of the amplifying element 3 over a wide band.

Furthermore, according to this invention, one side of the feedback circuit is attached to the auxiliary insulating plate, which facilitates assembly. Furthermore, since the structure includes one auxiliary insulating plate, it also has the advantage of being highly mechanically strong.

In the above embodiment, the case where two resistor layers 12 and 13 are formed on the auxiliary insulating plate 11 has been described, but it is easy to understand that the number is not limited to two.

[Brief explanation of the drawing]

Fig. 1 is a perspective view for explaining an embodiment of this invention, Fig. 2 is a perspective view for explaining the prior art, and Fig. 3 is a perspective view for explaining the electrical circuit structure of a high frequency feedback amplifier. It is a connection diagram. 3: Active element for high frequency amplification, 4: Output side terminal,
6: Input side terminal, 7: Earth conductor, 8: Chip type capacitor, 11: Auxiliary insulating plate, 12, 13: Resistor layer, 14, 15, 16, 17: Conductive layer, 18, 1
9: Terminal.

Claims (1)

[Scope of Claim for Utility Model Registration] A. A main insulating substrate in which an input terminal and an output terminal are formed on one surface of an insulating plate, and an active element for high frequency amplification is connected to these terminals, and B. A main insulating substrate on one surface of an insulating plate. An auxiliary insulating plate formed by dividing into a plurality of resistor layers on a straight line and having a conductive layer formed at both ends of each of the plurality of resistor layers; a feedback resistor formed by series-connected capacitive elements; and the auxiliary insulating plate is vertically planted on the main insulating board through these terminals.