JP4031339B2 - Variable phase adjuster - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a variable phase adjuster.
[0002]
[Prior art]
The above variable phase adjuster may be used, for example, when configuring a variable directivity antenna. An example in which this variable directivity antenna is configured is disclosed in Patent Document 1.
[0003]
[Patent Document 1]
JP 57-127302 A (page 4, FIG. 6)
[0004]
In Patent Document 1, two antennas are arranged so as to receive radio waves from the same direction at a predetermined distance, and a reception signal from one antenna is supplied to an in-phase synthesizer via a reverse phase transformer. A signal received by the other antenna is supplied to the above-mentioned in-phase synthesizer via a variable phase shifter and an in-phase transformer. The variable phase shifter includes a variable capacitance capacitor connected in parallel.
[0005]
[Problems to be solved by the invention]
In the variable phase adjuster as described above, the phase is adjusted by changing the capacitance of the variable capacitance capacitor. By the way, when the antenna is for receiving a high frequency such as the UHF band, the capacitance change required for the variable capacitance capacitor is about 0 to 2 pF, and it is desirable that fine adjustment can be made particularly in the range of 0 to 1 pF. It is. However, it is extremely difficult to obtain a very small capacitance of 1 pF or less with a variable capacitor. Also, fine adjustment in the range of 0 to 2 pF is difficult. Since fine adjustment of the capacity is difficult, fine adjustment of the phase change is also impossible.
[0006]
An object of the present invention is to provide a variable phase adjuster capable of easily performing fine phase adjustment.
[0013]
[Means for Solving the Problems]
The variable phase adjuster of one aspect of the present invention has a second high-frequency signal terminal whose one end is connected to the output terminal so as to be electromagnetically coupled to the first transmission line for the high-frequency signal whose one end is connected to the input terminal. Coupling means in which the transmission lines are arranged, and two microstrip line stubs provided between the other ends of the first and second transmission lines and a reference potential point, respectively. . Each stub has two arcuate portions arranged in line symmetry. Two gears are disposed concentrically with these arcuate portions and mesh with each other. It is desirable to use gears having the same diameter and the same number of teeth. Short-circuit means is provided on the surface of the gears on the arc-shaped portion side. The short-circuit means short-circuits the arc-shaped portion to the reference potential point while rotating symmetrically with the same angle with respect to the reference position according to the rotation of both gears.
[0014]
If comprised in this way, since a stub has an arc-shaped part, it can reduce in size rather than the case where the stub which formed all linearly is used. Further, since the short-circuit means is rotated by the gear, the angles formed by the two short-circuit means with respect to the reference position are always equal, and the capacities of the stubs are always equal.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the variable phase adjuster 2 of the first reference example of the present invention combines the received signals of the two antennas 4 and 6 by the combiner 8. Used to adjust the phase.
[0018]
As the antennas 4 and 6, various known antennas can be used. For example, a directional antenna such as a Yagi antenna is used. These antennas 4 and 6 are configured to receive radio waves in the same frequency band, for example, UHF band, and are further arranged to receive radio waves arriving from the same direction. The reception signal of the antenna 4 is supplied to the combiner 8 as it is. On the other hand, the received signal of the antenna 6 is supplied to the combiner 8 after the phase is adjusted by the variable phase adjuster 2. The synthesizer 8 synthesizes the supplied signals in phase or in reverse phase.
[0019]
The variable phase adjuster 2 has transmission means, for example, directional coupling means, specifically a 3 dB coupler line 10. The coupler line 10 has an input terminal 11 connected to the antenna 6. One end of the first transmission line 12 is connected to the input terminal 11 via a capacitor 14. The second transmission line 16 is also provided in the coupler line 10 so as to be electromagnetically coupled to the first transmission line 12. One end of the second transmission line 16 is connected to an output terminal 19 via a capacitor 18. The output terminal 19 is connected to the synthesizer 8.
[0020]
Microstrip line stubs 20 and 22 are provided at the other ends of the first and second transmission lines 12 and 16. These stubs 20 and 22 are formed on one substrate 24. The substrate 24 is formed in a rectangular shape, for example, and although not shown, a metal foil serving as a ground conductor is formed on the entire back surface thereof. Stubs 20 and 22 are provided on the surface side of the substrate 24. Originally, the metal foil was formed on the entire surface of the substrate 24, but the stubs 20 and 22 are formed in a line at predetermined intervals by appropriately etching the metal foil. Around the stubs 20 and 22, a metal foil serving as a ground potential surface 26 is left. The stubs 20 and 22 are formed in the same shape, and the characteristic impedance including the coupler line 10 is set to 50Ω or 75Ω. The length of the stubs 20 and 22 can be set to 80 mm, for example. One ends of these stubs 20 and 22 are connected to the other ends of the first and second transmission lines 12 and 16, and the other ends are opened.
[0021]
These stubs 20 and 22 are provided with short-circuit means, for example, short bars 28 and 30. The short bars 28 and 30 are arranged perpendicular to the length direction of the stubs 20 and 22. The central portions of the short bars 28 and 30 are in contact with the stubs 20 and 22, and both end portions of the short bars 28 and 30 are in contact with the ground potential surface 26. The short bars 28 and 30 are slidable along the length direction of the stubs 20 and 22.
[0022]
Accordingly, the short bar 28 short-circuits the stub 20 at an arbitrary distance L1 from the connection end with the first transmission line 12. Similarly, the short bar 30 also short-circuits the stub 22 at an arbitrary distance L2 from the connection end with the second transmission line 16. The short bars 28 and 30 are configured to be interlocked so that the distances L1 and L2 are always equal by operating an operator (not shown). Therefore, the same capacity is always connected to the other ends of the first and second transmission lines 12 and 16.
[0023]
In the variable phase adjuster 2 configured as described above, the signal and the output at the input terminal 11 are changed by changing the distances L1 and L2 of the short bars 28 and 30 in the range of 0 to 80 mm (the total length of the stubs 20 and 22). The amount of phase change between the signal at the terminal 19 is 0 to 180 degrees at a frequency of 470 MHz.
[0024]
In the variable phase adjuster 2, the value of the capacitance connected to the first and second transmission lines 12 and 16 changes. In addition, since the capacities of the stubs 20 and 22 are changed by changing the short-circuit position in the microstripline stubs 20 and 22, fine adjustment can be easily performed with a small capacity. Therefore, fine adjustment of the phase can be easily performed, and for example, a desired null point can be easily obtained.
[0025]
In the first reference example, straight stubs 20 and 22 were used. However, if it is necessary to reduce the area for installing the stubs, by adopting the structure shown in FIGS. 2-5, it is possible to reduce the installation area.
[0026]
That is, in the second reference example shown in FIG. 2, the stubs 20a and 22a are formed in a zigzag shape.
[0027]
In the third reference example shown in FIG. 3, the stubs 20b and 22b are formed in a sine wave shape. 2 and 3, the ground potential surface 26 is not shown, but the short bars 28 and 30 are in contact with the ground potential surface in addition to the stubs 20a, 20b, 22a and 22b. .
[0028]
In the first embodiment shown in FIG. 4, the stubs 20c and 22c are arc-shaped portions, for example, 3/4 arc-shaped portions 20c-1 and 22c-1, and linear portions 20c-2 and 22c-2 connected thereto. It consists of and. These arc-shaped portions 20c-1 and 22c-1 are arranged line-symmetrically at a predetermined interval.
[0029]
Gears 32 and 34 are formed on the back side of the substrate 24 concentrically with the arcuate portions 20c-1 and 22c-1. These gears 32 and 34 have the same diameter and the same number of teeth. Short bars 28a and 30a are formed in line symmetry so as to be coupled to the gears 32 and 34 and located on the surface side of the substrate 24 and to slide on the arcuate portions according to the rotation of the gears 32 and 34. The short bars 28a and 30a are in contact with the arcuate portions 20c-1 and 22c-1, and are in contact with a ground potential surface (not shown). In the substrate 24, annular grooves 36 and 38 for moving the short bars 28a and 30a are formed concentrically with the gears 32 and 34, respectively.
[0030]
The gears 40 and 42 are engaged with the gears 32 and 34 on the back surface side of the substrate 24. Further, the gears 40 and 42 are also engaged with each other. The gears 40 and 42 have the same diameter and the same number of teeth. Although not shown, a knob that can be operated from the side of the substrate 24 is provided at the center of one of the gears 40 and 42.
[0031]
When this knob is rotated, the gears 40 and 42 rotate in opposite directions, and the gears 32 and 34 also rotate in opposite directions. As a result, the short bars 28a, 30a are always at the same angle with respect to reference positions passing through the centers of the gears 32, 34 and parallel to the linear portions 30c-2, 32c-2, for example, the reference lines r1, r2. Rotate in line symmetry. Accordingly, the capacities of both stubs 20c and 22c are always the same value.
[0032]
FIGS. 5A and 5B show a second embodiment. This embodiment is configured substantially the same as the first embodiment. Equivalent parts are denoted by the same reference numerals and description thereof is omitted. In this embodiment, unlike the first embodiment, gears 32a and 34a are provided on the surface on the substrate 24 side where the stubs 20c and 22c are provided. These gears 32a and 34a are arranged concentrically with the 3/4 arc-shaped portions 20c-1 and 22c-1, and mesh with each other. The gears 32a and 34a have the same diameter and the same number of teeth. Short bars 28a and 30a are formed in line symmetry on the surfaces of the gears 32a and 34a on the stub 20c and 22c side. Accordingly, as in the first embodiment, the short bars 28a and 30a rotate while always making the same angle with respect to the reference lines r1 and r2. A knob 43 is provided on the upper surfaces of the gears 32a and 34a. By rotating this, the gears 32a and 34a rotate, and the short bars 28a and 30a rotate at the same angle in line symmetry. Accordingly, the capacities of both stubs 20c and 22c are always the same value. Further, it is possible to reduce the size as compared with the case where the stubs 20 and 22 are all formed linearly as in the first reference example . Furthermore, since the gears 32a and 34a are provided on the stubs 20c and 22c side, a groove (see the first embodiment) for rotating the short bars 28a and 30a is not necessary, and the configuration can be simplified. 5A and 5B, the ground potential plane around the stubs 20c and 22c is omitted. The short bars 28a and 30a are connected to the ground potential surface.
[0033]
Further, as in the fourth reference example shown in FIG. 6, a variable capacitance element having a trombone structure can also be used. This variable capacitance element has a center conductor 44. A fixed outer conductor 46 is fixedly disposed so as to surround the center conductor 44 with a space therebetween. A movable outer conductor 48 is provided between the fixed outer conductor 46 and the center conductor 44 so as to be movable in the length direction of the outer conductor 46. The movable outer conductor 48 has a hollow cylindrical shape.
[0034]
Two variable capacitance elements are provided, the center conductor 44 of one variable capacitance element is connected to the other end of the first transmission line 12 of the coupler line 10, and the center conductor 44 of the other variable capacitance element is The other transmission line 16 is connected to the other end. By inserting and removing the movable outer conductor 48 from the fixed outer conductor 46, the area covered by the movable outer conductor 48 in the center conductor 44 changes, and the capacitance changes. Of course, the movable outer conductor 48 moves in conjunction with the two variable capacitance elements.
[0035]
When this variable capacitance element is used, the value of the capacitance connected to the other ends of the first and second transmission lines 12 and 16 changes with the same value. In addition, minute capacitance adjustment is possible by changing the amount of insertion of the movable outer conductor 48.
[0036]
In each of the above embodiments, the 3 dB coupler line 10 is used. However, the present invention is not limited to this. For example, a transmission line having reactance is provided, and a microstrip line stub as described above is provided at a predetermined position thereof. It is also possible to provide a trombone variable capacitor. In each of the above embodiments, the stub is an open end that is not connected to the coupler line 10, but may be a short-circuited end that is short-circuited to the ground potential point.
[0037]
【The invention's effect】
As described above, according to the present invention, a minute change in capacitance can be given, so that fine adjustment of the phase can be easily performed.
[Brief description of the drawings]
FIG. 1 is a block diagram of a variable phase adjuster according to a first reference example of the present invention.
FIG. 2 is a block diagram of a variable phase adjuster of a second reference example of the present invention.
FIG. 3 is a block diagram of a variable phase adjuster according to a third reference example of the present invention.
FIG. 4 is a block diagram of a variable phase adjuster according to the first embodiment of this invention.
FIG. 5 is a block diagram of a variable phase adjuster according to a second embodiment of this invention.
FIG. 6 is a block diagram of a variable phase adjuster of a fourth reference example of the present invention.
[Explanation of symbols]
10 Coupler line (Transmission means, coupling means)
12 First Transmission Line 16 Second Transmission Line 20 22 Microstrip Line Stub 28 30 Short Bar (Short-Circuit Means)
44 Center conductor 46 Fixed outer conductor 48 Movable outer conductor

Claims (1)

A coupling means in which a second transmission line for high-frequency signals whose one end is connected to the output terminal so as to be electromagnetically coupled to the first transmission line for high-frequency signals whose one end is connected to the input terminal;
Two microstrip line stubs provided between the other ends of the first and second transmission lines and a reference potential point,
These stubs have
Two arcuate portions arranged in line symmetry,
On these arcuate parts, two gears arranged concentrically with these and meshing with each other;
Short-circuit means provided on the surface of the gears on the side of the arcuate part and short-circuiting the arcuate part to the reference potential point while rotating symmetrically with respect to a reference position according to the rotation of the two gears. And
Having a variable phase adjuster.

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