JP2004129045A - Variable phase adjuster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable phase adjuster which performs very small phase adjustment. <P>SOLUTION: A coupler line 10 is provided between an input terminal 11 and an output terminal 19. The coupler line 10 has a first transmission line, the one end of which is connected to the input terminal 11 and a second transmission line 16, the one end of which is connected to the output terminal 19. Microstrip line type stubs 20 and 22 are provided at the other ends of the first and second transmission lines 12 and 16. The stubs 20 and 22 have short bars 28 and 30 that can change connection positions to a reference potential point. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD 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 directional antenna. Patent Document 1 discloses an example in which this variable directional antenna is configured.
[0003]
[Patent Document 1]
JP-A-57-127302 (page 4, FIG. 6)
[0004]
In Patent Literature 1, two antennas are arranged so as to receive radio waves from the same direction at a predetermined distance, and a signal received by one antenna is supplied to an in-phase combiner via an anti-phase transformer. The signal received by the other antenna is supplied to the above-mentioned in-phase combiner via the variable phase shifter and the 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 particularly desirable that the capacitance can be finely adjusted 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 in the variable capacitance capacitor due to its structure. Also, it is difficult to make fine adjustments in the range of 0 to 2 pF. Since it is difficult to finely adjust the capacitance, it is not possible to finely adjust the phase change.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a variable phase adjuster that can easily finely adjust the phase.
[0007]
[Means for Solving the Problems]
In the variable phase adjuster according to one embodiment of the present invention, a high-frequency signal transmission unit is provided between the input terminal and the output terminal. This transmission means is at least inductive. A microstrip line type stub is provided between the transmission means and the reference potential point. This stub has short-circuit means that can change the connection position to the reference potential point. For example, the stub may have a connection end to the transmission means and an open or short end spaced further therefrom, wherein the short-circuit means may be located anywhere between the connection end and the lower end. , Connect the stub to the reference potential point.
[0008]
In the variable phase adjuster configured as described above, by changing the position of the short circuit means, the microstrip line type stub can be made capacitive or inductive. Therefore, by appropriately setting the position of the short-circuit means, the phase of the high-frequency signal supplied to the input terminal can be adjusted to a desired phase and output from the output terminal. In particular, since a microstrip line type stub is used, a capacitance proportional to the position of the short-circuit means can be obtained, and fine adjustment of the capacitance can be easily performed.
[0009]
A plurality of the stubs can be provided. It is desirable that stubs are provided at different positions on the transmission means. These stubs have a connection end to the transmission means and an open or shorted end. In each stub, the short-circuit means connects each stub to the reference potential point at a position where the distance from the connection end is equal.
[0010]
With this configuration, the stubs can always be configured to have the same capacity.
[0011]
In a variable phase adjuster according to another aspect of the present invention, coupling means is provided. The coupling means has first and second transmission lines for high frequency signals. One end of the first transmission line is connected to the input terminal. One end of the second transmission line is connected to the output terminal. The first and second transmission lines are arranged so as to be electromagnetically coupled to each other. Two stubs are provided between the other ends of the first and second transmission lines and the reference potential point, respectively. These stubs are of the microstrip line type. Each stub has a connection end to the other end of the first and second transmission lines and an open or short end. Shorting means for connecting the stub to the reference potential point at an arbitrary position where the distance from the connection end is equal to each other is provided in the microstrip line.
[0012]
Each stub can be set so that the total length from its connection position to the first and second transmission lines to its open end is longer than the linear distance from the connection position to the open end. With this configuration, the size of the variable phase adjuster can be reduced.
[0013]
A variable phase adjuster according to another aspect of the present invention has the same coupling means and stub as in the above aspect. Each stub has two arc-shaped portions arranged in line symmetry. Two gears are arranged concentrically on these arc-shaped portions and mesh with each other. Preferably, these gears have the same diameter and the same number of teeth. Short-circuit means are provided on the surface of the gear on the side of the arc-shaped portion. The short-circuiting means short-circuits the arc-shaped portion to a reference potential point while rotating symmetrically with respect to a reference position at the same angle in accordance with the rotation of the two gears.
[0014]
With such a configuration, since the stub has the arc-shaped portion, it is possible to reduce the size more than when using a stub in which all the stubs are formed in a straight line. Further, since the short-circuit means is rotated by the gear, the angle between the two short-circuit means with respect to the reference position is always equal, and the capacity of the stub is always equal.
[0015]
A variable phase adjuster according to another aspect of the present invention includes a high-frequency signal transmission unit provided between an input terminal and an output terminal, and a stub provided between the transmission unit and a reference potential point. I have it. The stub is composed of a central conductor, a fixed outer conductor arranged so as to surround the center conductor, and a movable outer conductor that moves between the fixed outer conductor and the center conductor.
[0016]
In the variable phase adjuster thus configured, the capacitance formed between the movable outer conductor and the center conductor is changed by changing the position of the movable outer conductor along the length direction of the center conductor. Can be done.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
When the variable phase adjuster 2 according to the first embodiment of the present invention combines the received signals of the two antennas 4 and 6 with the combiner 8 as shown in FIG. Used to adjust the phase.
[0018]
Various known antennas can be used for the antennas 4 and 6. For example, a directional antenna such as a Yagi antenna is used. The antennas 4 and 6 are identically configured to receive radio waves in the same frequency band, for example, UHF band, and are arranged to receive radio waves arriving from the same direction. The received signal of the antenna 4 is supplied to the synthesizer 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 combiner 8 combines these supplied signals in-phase or out-of-phase.
[0019]
The variable phase adjuster 2 includes a transmission unit, for example, a directional coupling unit, specifically, a 3 dB coupler line 10. This coupler line 10 has an input terminal 11 connected to the antenna 6. One end of a first transmission line 12 is connected to the input terminal 11 via a capacitor 14. A second transmission line 16 is also provided on the coupler line 10 so as to be electromagnetically coupled with the first transmission line 12. One end of the second transmission line 16 is connected to an output terminal 19 via a capacitor 18. This output terminal 19 is connected to the synthesizer 8.
[0020]
Microstrip line type 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, for example, in a rectangular shape, 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 front side of the substrate 24. The metal foil is originally formed on the entire surface side 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. These 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, 22 can be, for example, 80 mm. One ends of the 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 open.
[0021]
These stubs 20 and 22 are provided with short-circuit means, for example, short bars 28 and 30. The short bars 28, 30 are arranged perpendicular to the length direction of the stubs 20, 22. The center 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, respectively. The short bars 28, 30 are slidable along the length of the stubs 20, 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 end of the connection with the second transmission line 16. These short bars 28 and 30 are configured to operate in conjunction with each other by operating an operation member (not shown) so that the distances L1 and L2 always have the same value. Therefore, the same capacitance 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, by changing the distances L1 and L2 between the short bars 28 and 30 in the range of 0 to 80 mm (the total length of the stubs 20 and 22), the signal at the input terminal 11 and the output The phase change between the signal at the terminal 19 and 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, 16 changes. In addition, since the capacitance of the stubs 20 and 22 is changed by changing the short-circuit position in the microstrip line type 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 embodiment, linear stubs 20 and 22 are used. However, if it is necessary to reduce the area for installing the stub, it is possible to reduce the installation area by adopting a configuration like the second to fourth embodiments shown in FIGS. it can.
[0026]
That is, in the second embodiment shown in FIG. 2, the stubs 20a and 22a are formed in a zigzag shape.
[0027]
In the third embodiment shown in FIG. 3, the stubs 20b and 22b are formed in a sine wave shape. Although the ground potential surface 26 is not shown in FIGS. 2 and 3, the short bars 28 and 30 are in contact with the stubs 20a, 20b, 22a and 22b and also with the ground potential surface. .
[0028]
In the fourth 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 is composed of These arc-shaped portions 20c-1 and 22c-1 are arranged line-symmetrically at predetermined intervals.
[0029]
Gears 32 and 34 are formed on the back surface of the substrate 24 concentrically with the arc-shaped portions 20c-1 and 22c-1. The gears 32 and 34 have the same diameter and the same number of teeth. Short bars 28a, 30a are connected to the gears 32, 34 and located on the surface side of the substrate 24, and are formed to be linearly symmetric so as to slide on the arc-shaped portion according to the rotation of the gears 32, 34. The short bars 28a and 30a are in contact with the arc-shaped portions 20c-1 and 22c-1, and are in contact with a ground potential surface (not shown). On the substrate 24, annular grooves 36, 38 for moving the short bars 28a, 30a are formed concentrically with the gears 32, 34.
[0030]
Gears 40 and 42 mesh with gears 32 and 34 on the back side of the substrate 24. Further, the gears 40 and 42 are also engaged. The gears 40 and 42 have the same diameter and the same number of teeth. Although not shown, a knob operable from the substrate 24 side is provided at one center of the gears 40 and 42.
[0031]
When the 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 always make the same angle with respect to a reference position 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. Therefore, the capacities of both stubs 20c and 22c always have the same value.
[0032]
5A and 5B show a fifth embodiment. This embodiment is configured in substantially the same manner as the fourth embodiment. Equivalent portions are denoted by the same reference numerals, and description thereof is omitted. In this embodiment, unlike the fourth embodiment, gears 32a and 34a are provided on the surface of the substrate 24 on which the stubs 20c and 22c are provided. The 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, 30a are formed line-symmetrically on the surfaces of the gears 32a, 34a on the stub 20c, 22c side. Therefore, as in the fourth embodiment, the short bars 28a, 30a rotate while always forming the same angle with respect to the reference lines r1, r2. A knob 43 is provided on the upper surfaces of the gears 32a and 34a. By rotating this, the gears 32a, 34a rotate, and the short bars 28a, 30a rotate the same angle line-symmetrically. Therefore, the capacities of both stubs 20c and 22c always have the same value. Further, the size can be reduced as compared with the case where all the stubs 20 and 22 are formed linearly as in the first embodiment. Further, since the gears 32a and 34a are provided on the stubs 20c and 22c, a groove (see the fourth embodiment) for rotating the short bars 28a and 30a is not required, and the configuration can be simplified. In FIGS. 5A and 5B, a ground potential surface around the stubs 20c and 22c is omitted. The short bars 28a, 30a are connected to this ground potential surface.
[0033]
Further, as in the sixth embodiment shown in FIG. 6, a variable capacitance element having a trombone structure can be used. This variable capacitance element has a center conductor 44. A fixed outer conductor 46 is fixedly arranged so as to surround the center conductor 44 at an interval. 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 longitudinal direction of the outer conductor 46. The movable outer conductor 48 has a hollow cylindrical shape.
[0034]
Two of these 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 2 is connected to the other end of the transmission line 16. By inserting and removing the movable outer conductor 48 from the fixed outer conductor 46, the area of the center conductor 44 covered by the movable outer conductor 48 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 at the same value. In addition, by changing the insertion amount of the movable outer conductor 48, it is possible to finely adjust the capacitance.
[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 type stub or a stub as described above is provided at a predetermined position. It is also possible to provide a trombone-type variable capacitance element. Further, in each of the above embodiments, the end of the stub that is not connected to the cup line 10 is the open end, 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, since a minute change in capacitance can be given, 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 embodiment of the present invention.
FIG. 2 is a block diagram of a variable phase adjuster according to a second embodiment of the present invention.
FIG. 3 is a block diagram of a variable phase adjuster according to a third embodiment of the present invention.
FIG. 4 is a block diagram of a variable phase adjuster according to a fourth embodiment of the present invention.
FIG. 5 is a block diagram of a variable phase adjuster according to a fifth embodiment of the present invention.
FIG. 6 is a block diagram of a variable phase adjuster according to a sixth embodiment 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 type stub 28 30 Short bar (short means)
44 center conductor 46 fixed outer conductor 48 movable outer conductor

Claims (6)

Transmission means for a high-frequency signal provided between the input terminal and the output terminal,
A microstrip line type stub provided between the transmission means and the reference potential point,
A variable phase adjuster, wherein the stub includes a short-circuit unit that can change a connection position to the reference potential point. 2. The variable phase adjuster according to claim 1, wherein a plurality of said stubs are provided, each of said stubs having a connection end to said transmission means and an open end or a short-circuit end, and a distance from said connection end. A variable phase adjuster in which the short-circuit means connects each of the stubs to the reference potential point at the same position. Coupling means having a second transmission line for high-frequency signals connected to the output terminal at one end so that one end is electromagnetically coupled to the first transmission line for high-frequency signals connected to the input terminal;
Two microstrip line-type stubs provided between the other end of the first and second transmission lines and a reference potential point, respectively;
Wherein each of the stubs has a connection end to the other end of the first and second transmission lines and an open end or a short-circuit end, and any distance from the connection end is equal to each other. A variable phase adjuster having shorting means for connecting the stub to the reference potential point at a location. 4. The variable phase adjuster according to claim 3, wherein each of said stubs has a total length from a connection position to said first and second transmission lines to an open end thereof, from said connection position to said open end or short-circuit end. Variable phase adjuster set longer than the linear distance to the section. Coupling means having a second transmission line for a high-frequency signal connected to the output terminal at one end so that one end is electromagnetically coupled to the first transmission line for the high-frequency signal connected to the input terminal;
Two microstrip line type stubs provided between the other end of the first and second transmission lines and a reference potential point, respectively;
Have these stubs
Two arc-shaped parts symmetrically arranged,
On these arc-shaped parts, two gears arranged concentrically with and meshing with each other;
Short-circuit means provided on the surface of the gear on the side of the arc-shaped portion, and short-circuiting the arc-shaped portion to a reference potential point while rotating symmetrically with respect to a reference position while forming the same angle with respect to the rotation of the two gears. And
Variable phase adjuster. Transmission means for a high-frequency signal provided between the input terminal and the output terminal,
A stub provided between the transmission means and the reference potential point,
A variable phase adjustment comprising a center conductor, a fixed outer conductor arranged so as to surround the center conductor, and a movable outer conductor moving between the fixed outer conductor and the center conductor. vessel.

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