JPS5825601Y2 - high frequency electronic equipment - Google Patents

Description

[Detailed description of the invention] This invention has a structure in which a high-impedance circuit element is provided in the case, a low-impedance connection terminal is provided in the case, and the circuit element and the terminal are connected via a conductive wire. Regarding electronic equipment.

Conventionally, equipment for transmitting high-frequency signals generally uses a power feed line with an impedance of 7FM, so a 75Ω terminal called a plug is used as the terminal provided on the case of the equipment. There are many cases.

For this reason, it is considered preferable to use circuit elements provided within the case that have a low high-frequency impedance corresponding to the impedance of the circuit elements.

In such devices, impedance matching between terminals and circuit elements is extremely simple, and internal wiring can be done using commonly known coaxial cables, but in some cases, circuit elements with low high frequency impedance can be extremely expensive. be.

(For example, a switch with low high frequency impedance costs about 3,000 yen.

On the other hand, a high-frequency impedance switch with an equivalent switch function may cost as little as 300 yen.

) Even in such a case, if the impedance matching is assumed, expensive circuit elements must be used, which is extremely uneconomical.

On the other hand, if a circuit element with high high frequency impedance is used based on the above-mentioned economic efficiency, if it is connected to a terminal with a conductor as shown in Fig. 7, a mismatch will occur.
As is well known, a low-quality signal different from the input signal is supplied to the circuit elements, which has the disadvantage that the function of the electronic circuit is significantly impaired.

In order to solve this problem, it may be possible to use a matching box for the above connection to ensure proper matching, but considering the price of the matching box and the time it takes to install it, it ends up being expensive and not economical. It will be difficult to implement.

Therefore, the present invention provides an extremely simple and inexpensive connection consisting of a core wire and an outer conductor wound spirally around the core wire when connecting a terminal with low high frequency impedance and a circuit element with high high frequency impedance. The aim is to provide a structure in which an appropriate matching state can be obtained even when the two are connected using a wire.

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

FIG. 1 shows an antenna switching device as an example of high-frequency electronic equipment, and FIG. 2 shows its circuit diagram.

In these figures, 1 is a case made of a conductive material (for example, aluminum).

Reference numerals 2 and 3 are connection terminals fixed to the case 1, which allow signals from receiving antennas 4 and 5 to be input, respectively.

Further, as these connection terminals 2 and 3, low impedance (for example, 75Q) plugs are used.

(Note that this impedance indicates the characteristic impedance of the terminal itself as an example, but may also indicate the impedance defined by the power supply line connected to the terminal.

) 6 is a connection terminal, which transmits a selected television signal to a television receiver 7 as described later.

Further, as this terminal 6, a plug similar to that described above is used.

Reference numeral 8 denotes a changeover switch exemplified as a circuit element provided in the case 1, and a double-pole double-throw switch as shown in FIG. 2 is used.

Note that 9□ and 9□ are switching contacts, and 10. ．． 102, 11. . 1
1□ indicates a fixed contact, respectively.

Further, this switch 8 can be operated from the outside (surface) of the case 1, as is well known.

Furthermore, the switch used has a high high frequency impedance (for example, 110Q).

Reference numeral 12 denotes a connecting wire, in which an outer conductor 14 is spirally wound around a core wire 13.

As the core wire 13 and the outer conductor 14, polyurethane copper wires of Q, 5 mm, and 9.4 mm are used, respectively.
The outer conductor 14 is connected between the outer conductor 2b of the terminal 2 and the contact 10□.

In addition, the pitch of the winding of the outer conductor 14 around the core wire 13 is such that the pitch in the part A near the terminal 2 is dense (for example, 0.5 mm), and the pitch in the part near the switch 8 is coarse (lQ mm). The impedance of the connecting line is made approximately equal to the impedance of the terminal 2 or the switch 8.

Moreover, the pitch of the middle part C is about halfway between the parts indicated by A and A above.

The winding pitch may be selected as follows.

That is, when the aforementioned ones are used as examples of the core wire 13 and the outer conductor 14, respectively, the relationship between pitch and impedance is as shown in FIG. 5.

Therefore, from such a graph, it is sufficient to determine a pitch that provides an impedance that matches the impedance of the terminal and switch.

Further, other conducting wires may be used as the core wire 13 and the outer conductor 14.

In that case, one may use a bare copper wire.

Connection lines 15 and 16 connect the terminal 3 or 6 and the switch 8, and are constructed in the same manner as the connection line 12, respectively.

In the above configuration, the signal entering the terminal 2 or 3 is transferred to the connecting wire 12 or 1 with good impedance matching.
5 and further to switch 8 with good impedance matching.

Furthermore, one of the signals selected by the switching operation of the switch 8 is transmitted to the terminal 6 through the connection line 16 with good impedance matching, and is output as a good signal.

FIG. 3 shows the results of measuring the VSWR characteristic of the above structure, and FIG. 4 shows the results of measuring the inter-terminal coupling loss and insertion loss, respectively, as solid lines.

In these figures, the characteristics of the conventional structure shown in FIG. 7 are also shown by broken lines.

The above configuration has good impedance matching, so
It is understood from these figures that extremely good values were obtained for each characteristic.

Next, FIG. 6 shows a different embodiment of the present application.

This figure shows an amplifier device as an example of high-frequency electronic equipment, and an amplifier circuit 21 is housed inside a case 1e.

22 and 23 indicate an input section and an output section, respectively.

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, when connecting the connection terminal 2 with low high frequency impedance and the circuit element with high high frequency impedance inside the case, the outer conductor 14 is spirally wound around the outer periphery of the core wire 13. Since the pitch is such that the connection is made using the connection wire 12 in which the low impedance side is tightly wound and the high impedance side is wound loosely, the high impedance part and the low impedance part must be connected to each other in a proper matching state. This has the effect of allowing high frequency signals to pass through properly.

This also means that, for example, if a circuit element with a low high frequency impedance that should be installed in correspondence with a terminal with a low high frequency impedance is relatively expensive, the circuit element must be a circuit element with a high high frequency impedance (cheaper than a low impedance one). ), and as a result, the cost associated with circuit elements can be significantly reduced, resulting in a significant effect in reducing the cost of the entire device.

Moreover, the above connection wire 12 has an outer conductor 1 on the outer periphery of the core wire 13.
Since the core wire 13 is merely wound spirally, even if impedance matching is inappropriate near the circuit element with high high frequency impedance, the core wire 13
There are also operational features that allow for easy adjustment, such as the ability to obtain a preferred alignment by appropriately adjusting the pitch of the outer conductor 14 wound around the outer conductor 14 .

[Brief explanation of the drawing]

The drawings show an embodiment of the present application. Fig. 1 is a perspective view of the antenna switch (with the bottom cover removed), Fig. 2 is the circuit diagram, and Figs. 3 to 5 show the characteristics. FIG. 6 is a diagram showing a different embodiment, and FIG. 7 is a diagram showing a conventional example. 2... Connection terminal, 8... Switch, 1
2... Connection wire, 13... Core wire, 14.
...Outer conductor.

Claims (1)

[Scope of utility model registration request] The case is equipped with a connection terminal with low high frequency impedance, and the inside of the case is equipped with a circuit element with high high frequency impedance. The connection is made using a connection wire consisting of a conductor, and the pitch of the winding of the external conductor in the connection wire is such that the pitch on the side of the connection terminal is close to obtain an impedance that matches the low high-frequency impedance of the connection terminal. A high-frequency electronic device characterized in that, on the other hand, the pitch of the part closer to the circuit element is extremely coarser than that of the connection terminal side so as to obtain an impedance that matches the high high-frequency impedance of the circuit element.