JPH0828601B2 - High frequency rotation relay circuit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a high-frequency rotation relay circuit which transmits a high-frequency signal and whose mechanical portion is rotatable.

[Prior Art and its Problems] In the conventional high-frequency rotation relay circuit as described above, for example, as shown in FIG. 7, an external reference potential portion 4 is provided so as to surround the periphery of the signal line 2 and Two coaxial paths having circular pole plates 6 provided at the tip of the wire 2 are formed, and the two coaxial paths are arranged so that the pole plates 6 of both coaxial paths face each other and both coaxial paths rotate in phase. Connect the signal lines 2 of both coaxial lines to the pole plate 6
Some are combined depending on the capacity between. However, in this case, for example, the diameter of the circular electrode plate 6 is 10 mm, and the distance between both electrode plates 6 is
When it is set to 1 mm, the capacitance between the electrode plates 6 is about 1.5 pF, which is 1 GHz.
When transmitting a signal of a certain frequency, there is a problem that the impedance becomes large and the transmission loss characteristic deteriorates as shown in FIG.

In order to cancel the capacitance between the pole plates 6, it is conceivable to insert a lumped constant coil 8 between the signal line 2 and the pole plate 6 as shown in FIG. When stray capacitance is generated between the external reference potential section 4 as shown by the dotted line and it is improved compared to the case of Fig. 8, but when transmitting a signal with a frequency of about 1 GHz as shown in Fig. 10. However, there was a problem that the transmission loss characteristic was still poor.

Further, instead of providing the polar plate as shown in FIG. 11, it is also possible to provide the lumped constant coil 10 at the tip of the signal line 2. However, in this case, as shown by the dotted line, the distributed capacitance generated between the lumped constant coils 10 is too small, the inductance is large and the capacitance is small, so that the Q is high, and as shown in FIG. Is very limited.

An object of the present invention is to provide a high frequency rotary repeater circuit having a small transmission loss over a relatively wide band.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a signal line,
An external reference potential portion provided so as to surround the signal line, and an end portion of the signal line which is disposed substantially at a right angle to the end portion of the signal line. Two coaxial paths each having a spiral-shaped inductance element are provided so that the two inductance elements generate a distributed capacitance between at least the two, and the distributed capacitance and the inductance element form a band-pass filter. The two inductance elements are arranged so as to face each other with a predetermined space therebetween, and are rotatably coupled with the centers of the both coaxial paths as rotation centers.

[Operation] According to the present invention, the spiral inductance elements respectively connected to the signal lines of the two coaxial paths, and at least the distributed capacitance therebetween form a bandpass filter. Since the facing area of the spiral inductance element is larger than that shown in FIG. 10, the distributed capacitance is large. Therefore, since Q becomes small, the band with small transmission loss becomes wide.

[Embodiment] In FIG. 1, reference numerals 12a and 12b are coaxial paths, which have signal lines 14a and 14b and external reference potential portions 16a and 16b, respectively, and the signal line 14a and the external reference potential portions 16a and 16b are located at the center positions. 14b is arranged. That is, the signal lines 14a and 14b and the external reference potential section 16
They are arranged concentrically with a and 16b. Although not shown in the figure, the signal lines 14a and 14b and the external reference potential parts 16a and 1b
A dielectric is disposed between the 6b and the so-called coaxial line.

Inductors 18a and 18b formed in a spiral shape are provided at the tips of the signal lines 14a and 14b, respectively.
They are arranged almost vertically on 14a and 14b. These inductance elements 18a and 18b are formed on the printed circuit boards 20a and 20b by etching or the like as shown in FIGS. 2 and 3, and both are in the same winding direction from the central portions 19a and 19b, for example, right winding. It is formed in a spiral shape toward the outer peripheral portion in the direction. The tip ends of the signal lines 14a and 14b are coupled to the center parts 19a and 19b of the inductance elements 18a and 18b.

Both of the coaxial paths 12a and 12b are connected to the inductance element 18
a and 18b face each other while maintaining a predetermined distance, and the signal line
14a and 14b are located on the same straight line, and external reference potential parts 16a and 1
6b are arranged in contact and are rotatably coupled in mutually opposite directions as indicated by the arrows in FIG. Since this coupling structure is known, detailed description thereof will be omitted.

FIG. 4 is an equivalent circuit diagram of this high frequency rotation relay circuit.
The spiral inductance element 18a connected to the signal line 14a and the spiral inductance element 18b connected to the signal line 14b are disposed so as to face each other, and thus the distributed capacitances 22, 22, ... , And mutual induction couplings M, M generated between the two. Further, the external reference potential portions 16a and 16b are coupled by the stray capacitance 24 generated between them. Therefore, it forms a kind of bandpass filter. This equivalent circuit is a distributed constant circuit with the tip open, and the impedance Z between the central portions 19a and 19b of the spiral inductance elements 18a and 18b is expressed by the following equation.

Z = Jcotβl (l is the line length, β is the phase constant 2π /
λg) From this equation, when the spiral coil length is λg / 4, Z
= O and no loss occurs between the lines, and it operates as a repeater.

FIG. 5 shows the relationship between the transmission loss and the frequency of the high-frequency rotary relay circuit configured as described above. The solid line shows both inductance elements 18a and 1a as shown in FIG.
8b is the characteristic in the state where it is located, the dotted line shows the characteristic when the inductance element 18b is rotated 90 ° counterclockwise in FIG. 6, the dashed line shows the characteristic when it is also rotated 180 °, The alternate long and two short dashes line is the characteristic when it is also rotated by 270 °. Incidentally, FIG. 6 shows A in FIG.
-It is a drawing when the coaxial path 12a is seen along the A line. Two
Even if the individual spiral inductance elements 18a and 18b rotate, the area of the portion having the overlapping capacitance becomes substantially constant, and the change in the capacitance becomes substantially constant. The reason why there is a slight difference in characteristics due to such rotation is that the mutual inductive coupling M and the distributed capacitance slightly change depending on the rotational position. As is clear from these characteristics, in this embodiment, the transmission loss is about 1 dB at the maximum and about 0.3 bB at the minimum over a band wider than that shown in FIG. 12 from about 1 GHz to about 1.4 GHz. Therefore, for example, when the satellite broadcast receiving system is mounted on a moving object such as a ship and the azimuth and elevation of the satellite broadcast receiving antenna are changed according to the movement,
A converter attached to the satellite receiving antenna,
When used to connect to a tuner installed in a different position, the coaxial cable does not become entangled and the output of the converter in the 1GHz band can be transmitted with less transmission loss. The frequency band with low transmission loss can be arbitrarily changed by adjusting the length and width of the inductance elements 18a and 18b.

Although the spiral coils 18a and 18b are formed on the printed circuit boards 20a and 20b in the above-described embodiments, the spiral inductance element may be formed by winding the spiral coils 18a and 18b in a spiral shape. Further, in the above embodiment, the case where the high-frequency rotation relay circuit according to the present invention is used alone has been described. However, by connecting a plurality of these high-frequency rotation relay circuits in cascade, a complicated movement like a robot arm is performed. It can also be used for equipment.

[Effects of the Invention] As described above, according to the present invention, since both inductance elements arranged in a spiral shape are arranged facing each other and at least distributed capacitance coupling is performed, a lumped constant coil whose distribution capacitance is normal is used. It will be bigger than the one. Therefore, the Q of the bandpass filter formed by the inductance element and the distributed capacitance is reduced, and the transmission loss can be reduced over a wide band.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of one embodiment of a high-frequency rotation relay circuit according to the present invention, FIG. 2 is a plan view of one printed circuit board on which a spiral coil used in the embodiment is formed, and FIG.
FIG. 4 is a plan view of the other printed circuit board on which the spiral coil used in the embodiment is formed, FIG. 4 is an equivalent circuit diagram of the embodiment, and FIG. 5 is a transmission loss vs. frequency characteristic diagram of the embodiment. FIG. 6 is a partially omitted sectional view taken along the line AA of FIG.
FIG. 7 is a schematic configuration diagram of an example of a conventional high frequency rotation relay circuit, FIG. 8 is a transmission loss vs. frequency characteristic diagram of the high frequency rotation relay circuit of FIG. 7, and FIG. 9 is another conventional high frequency rotation relay circuit. FIG. 10 is a schematic configuration diagram of an example, FIG. 10 is a transmission loss vs. frequency characteristic diagram of the high frequency rotary relay circuit of FIG. 9, FIG. 11 is a schematic configuration diagram of still another example of the conventional high frequency rotary relay circuit, and FIG. FIG. 12 is a transmission loss vs. frequency characteristic diagram of the high frequency rotation relay circuit of FIG. 11. 12a, 12b ... Coaxial path, 14a, 14b ... Signal line, 16a, 16b ...
... External reference potential part, 18a, 18b ... Spiral inductance element.

Claims (1)

[Claims] 1. A signal line, an external reference potential portion provided so as to surround the signal line, a signal line, which is arranged substantially at a right angle to the tip of the signal line and is centered at the tip of the signal line. Are connected to each other, and two coaxial paths each having an inductance element on a spiral extending from the center to the outer circumference, the two inductance elements generate a distributed capacitance between at least the two, and the distributed capacitance and the inductance element A high-frequency rotary relay circuit in which the two inductance elements are arranged to face each other at a predetermined interval and are rotatably coupled with the centers of the both coaxial paths as rotation centers in a state where a bandpass filter is constituted by.