JP3095677B2 - Non-contact type coupling circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact type coupling circuit. In particular, the present invention relates to a non-contact type coupling circuit capable of continuously changing the phase of a high-frequency signal.

[0002]

2. Description of the Related Art Various types of phase shifters for continuously changing the phase of a high-frequency signal have been proposed.

As a typical example, there is a line stretcher system constituted by a coaxial tube. This changes the phase of the high-frequency signal by sliding the outer conductor and the inner conductor of the coaxial waveguide to each other and changing the length.

[0004]

In this type of phase shifter, the outer conductor and the inner conductor slide with respect to each other.
Poor contact may cause noise and intermodulation problems.

By transmitting signals having different phases to each antenna element of an array antenna in which a plurality of antenna elements are arranged, the direction of the main lobe of radiation from the array antenna can be changed. At this time, if a structure is adopted in which a line stretcher is connected for each cable that supplies power to each element,
The length of each line has to be finely adjusted, resulting in poor workability and high cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a phase shifter capable of continuously changing the phase with little noise generation and intermodulation due to poor contact, good workability, and low cost. Another object of the present invention is to propose a non-contact type coupling circuit having a large range in which the phase of a signal can be varied when used as a phase shifter.

[0007]

An object of the present invention is to provide a dielectric substrate, a conductor film covering a lower surface of the dielectric substrate, and an input strip line provided on an upper surface of the dielectric substrate and having an input terminal at one end. A rotating coupling conductor that is rotatable about the other end on the input side strip line and one end of which is coupled to the input side strip line via an insulator; A non-contact type coupling circuit comprising an output side strip line which is formed in an arc shape with the other end as a center, has output terminals at both ends and is coupled to the other end of the rotary coupling conductor via an insulator, a plurality of the output-side strip line includes a plurality of arm portions which the rotary coupling conductor extends radially from the rotation center, the rotation center of the rotary coupling conductor through the insulator above Combined with the force side strip line, the distal end of the respective arm portions via an insulator coupled with the respective output side strip lines, lambda] g the wavelength corresponding to the operating frequency
, The respective arm portions of the rotation coupling conductor are
And the above-mentioned arm coupled to the above-mentioned output strip line .
At the position of λg / 4 from the tip of the
Form a wide portion that is wider than the width, and
A first load impedance circuit is provided in a section up to the end, and the first load impedance circuit is provided from the rotation center of the rotation coupling conductor to the first load impedance circuit .
When the characteristic impedance to the load impedance circuit Z _IN, the equivalent characteristic impedance Z ₀ of the first load impedance _circuit, an impedance viewed the first of the output-side strip line from the load impedance Z _L, Z ₀ substantially satisfies the relationship of Z _IN Z _L = Z ₀ ² , and from the point λg / 4 from the other end coupled to the rotary coupling conductor of the input strip line, A second load impedance circuit is provided in a section up to the other end, and a characteristic impedance in a section from the input terminal to the second load impedance circuit is Z ₁ , and an equivalent characteristic impedance of the second load impedance circuit is Z _0, to the impedance seen on the output side from the other end of the input-side strip line and Z ₂ When was solved by a non-contact coupling circuit characterized by satisfying the relation of Z ₀ is approximately ^{_{Z 1 Z 2 = Z 0 2}} .

[0008]

[Operation] The signal sent from the input side stripline is split by the plurality of arms of the rotating coupling conductor,
It is further branched by an arc-shaped output-side stripline coupled to each arm via an insulator, and output from output terminals at both ends of each output-side strip. That is,
The non-contact type coupling circuit according to the present invention functions as a multi-stage branch circuit that branches off by a plurality of arms and then further branches off by an arc-shaped output-side stripline.

By rotating the rotary coupling conductor, the arms integrally formed with the rotary coupling conductor simultaneously rotate, and the coupling position between each arm and the output strip line changes. As a result, the phase of the output signal from one output terminal of each output side strip line advances, and the phase of the output signal from the other output terminal lags. At this time, if the radius of each arm portion is made different, even if the rotation angle of the rotary coupling conductor is the same, the amount of phase change of both output signals of each output side strip line can be made different, and the change amount can be changed. The amount is proportional to the radius of each arm.

When the output side strip line is viewed from the rotation coupling conductor, two load circuits are connected in parallel, so that the output impedance is reduced. A load impedance circuit as a quarter-wave transformer is provided on the output side strip line side of the coupling element in order to match the characteristic impedance of the input side strip line side portion of the rotary coupling conductor. The operation of the quarter-wave λ transformer is well known and will not be described. Similarly, when the side of the rotary coupling conductor is viewed from the input side strip line, a plurality of load circuits are connected in parallel via a plurality of arm portions, so that the output impedance is reduced. A second load impedance circuit as a quarter λ transformer is provided at the output end of the input strip line in order to match with the input strip line. Note that the wavelength λg of the strip line is determined by various parameters such as the frequency and the dimensions of the strip line. Therefore, the wavelength λg in the first load impedance circuit, the second load impedance circuit, and the quarter λ transformation circuit according to claim 4 is determined by the above parameters in each part, and is not the same as each other. Also, the wavelength λg of the input side strip line or the output side strip line is not always the same.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The non-contact type coupling circuit of the present invention is arranged in front of each antenna element of an Aire antenna, so that the phase of a feed signal of an array antenna can be continuously changed, and an onlay is provided. The direction of the main lobe of radiation from the antenna can be changed continuously.

[0012]

FIG. 1 is a conceptual perspective view of a preferred embodiment of a non-contact type coupling circuit according to the present invention, and FIG.
FIG. 3 is a sectional view taken along line BB of FIG.
FIG. 4 is a top view of the rotary coupling conductor and the output-side stripline of FIG.

A lower surface of a dielectric substrate 1 made of an electrically insulating material such as glass fluorine resin or alumina is covered with a conductive film 2 made of a conductive material such as copper.

A linear input-side strip line 3 and a plurality of arc-shaped output-side strip lines 4 are formed on an upper surface of a dielectric substrate 1.
A, 4B and 4C are formed.

An input terminal 3a is provided at one end of the input strip line 3, and each output strip line 4A, 4A
The output terminals 4Aa, 4Ab, 4Ba,
4Bb, 4Ca, and 4Cb are provided.

At the other end of the input-side strip line 3, an input-side strip line coupling portion 3b is provided, and each of the output-side strip lines 4A, 4B, 4C is formed in an arc shape centered on this.

The entire upper surface of the dielectric substrate 1, the input side strip line 3, and the output side strip line 4 has a thickness of 0.2.
It is coated with an insulator thin film 5 of about mm. FIG.
2, the insulator thin film 5 is omitted for simplicity.

A rotation coupling conductor 6 is rotatably provided on the insulating thin film 5. In this embodiment, the rotation coupling conductor 6
Has three arm portions 6A, 6B, 6C. The rotation axis and the like of the rotary coupling conductor 6 are also omitted for easy understanding of the drawing. The direction of rotation is indicated by arrow F.

The rotary coupling conductor 6 has an input side coupling portion 6a at a portion corresponding to the input side strip line coupling portion 3b of the input side strip line 3, and a rotation coupling conductor 6 on the output side strip line 4 side of each of the arm portions 6A, 6B, 6C. The output side coupling portion 6Ab at the end,
6Bb and 6Cb.

When the wavelength of the used frequency is λg, the output side coupling portions 6Ab, 6B of the respective arm portions 6A, 6B, 6C.
There are portions 6Ac, 6Bc and 6Cc whose widths are approximately circular and wide at positions λg / 4 from b and 6Cb.

Each of the portions 6Ac, 6B of which width is increased to this substantially circular shape from each of the output side coupling portions 6Ab, 6Bb, 6Cb.
The sections up to c and 6Cc are the first load impedance circuits 6Ad, 6Bd and 6Cd.

Assuming that the characteristic impedance of the output side strip line 4 is Z _OUT , each output side coupling portion 6Ab, 6B
b, 6Cb, the output-side stripline 4 is branched into two circuits, so that the first load impedances when viewing the output-side stripline side from each output-side coupling portion are approximately Z, respectively.
_OUT / 2.

Each arm 6A, 6B, 6 of the rotation coupling conductor
The characteristic impedance of the input side of C is Z _IN .
Usually, since Z _OUT = Z _IN = 50Ω, matching cannot be achieved as it is. In the present invention, the impedance is converted by the quarter-wave transformer composed of the first load impedance circuits 6Ad, 6Bd, and 6Cd to achieve matching.

Each first load impedance circuit 6Ad,
The capacitance of 6Bd and 6Cd is C, and the group velocity of the signal is
v_PThen, the equivalent characteristic impedance Z of this part_O
Is Z _O= (V_PC)^-1And the output side coupling unit 6b
Impedance matching condition is Z_IN・ Z_OUT= Z_O ^Two
Becomes

As shown in FIGS. 1 and 4, the rotary coupling conductor 6 is provided with circularly widened portions 6Ac, 6Bc, 6Cc at the respective first load impedance circuits. As a result, the matching condition is satisfied by increasing the capacitance C and decreasing the equivalent impedance Z _O.

As is apparent from the above description, the shape of each first load impedance circuit is not limited to those shown in FIGS. 1 and 4, but the width of the line at this portion must be increased. It can also be realized by adjusting the capacitance C by using the method described above.

In the non-contact type coupling circuit of the present invention, each of the first load impedance circuits 6Ad, 6Bd, 6Cd
, Each output side coupling part 6Ab,
6Bb and 6Cb are output strip lines 4A, 4B,
To prevent the width of 4C or its peripheral edge loss, it is sufficient to make it slightly larger than its width, and it is possible to make it smaller than λg / 4, so that the arc-shaped output side strip lines 4A, 4B, 4C When the size is given, the rotatable range of the rotation coupling conductor 6 is wide. This means that the range in which the phase of the signal can be varied is large.

A similar measure is taken between the input stripline 3 and the rotary coupling conductor 6. That is, the second load impedance circuit 3c is provided near the output end of the input strip line 3.

The characteristic impedance of the input side strip line 3 is Z ₁ , and each arm 6A, 6B, 6
Assuming that the characteristic impedance of C is Z ₃ , Z ₁ = Z
₃ = 50Ω, and the rotation coupling conductor 6 has three arm portions 6
A, 6B, and 6C, three loads are connected in parallel when viewed from the input side strip line 3 to the output side, and the output impedance when viewed from the rotary coupling conductor 6 side is 50.
Ω / 3, and matching cannot be achieved as it is.

The second load impedance circuit 3c is formed as a quarter λ transformer. When its characteristic impedance _{Z 2, Z 1 · Z 3} = Z 2 2 is matching condition.

[0031] In the present invention by increasing the width of the line portion of the second load impedance circuit 3c, by increasing the electrostatic capacitance C of the part, to reduce the characteristic impedance Z _3, taking the matching .

As is clear from the above description, the second load impedance circuit 3c is not only realized by increasing the width of the line, but also, for example, similar to the first load impedance circuits 6Ad, 6Bd, 6Cd. This can also be realized by providing a portion similar to the circularly widened portions 6Ac, 6Bc, 6Cc.

FIG. 5 is a return loss characteristic diagram of an example of the non-contact type coupling circuit of FIGS.
_o is a frequency corresponding to λg / 4 in FIG. In the band of 22%, -14 dB (standing wave ratio of 1.5) is obtained.

FIG. 6 is a graph showing the passage loss characteristics of the same non-contact type coupling circuit as in FIG. 5, wherein the values appearing at the output terminals 4Aa and 4Ab (solid line), 4Ba and 4Bb (dotted line), and 4Ca and 4Cb (dashed line). Was the same.

FIG. 7 is a conceptual top view of a rotary coupling conductor and an output side strip line in another embodiment of the present invention.

This embodiment is an improvement of the rotary coupling conductor of FIG. Therefore, corresponding components are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, in order to change the power distribution ratio of the rotary coupling conductor 6 to each of the arms 6A, 6B, 6C, at least one arm 6A, 6A, 6B and 6C output side coupling sections 6Ab and 6
In a section having a length of λg / 4 toward Bb and 6Cb, λ transforming circuits 6Ae, 6Be, and 6Ce are formed by reducing or widening the line width in the section.

This is because, when this non-contact type coupling circuit is used in the input stage of an array antenna, the excitation power applied to each antenna element is changed so that the angle characteristics of the vertical plane directivity of radiation from the array antenna can be improved. This is effective when changing the shape.

[0039]

【The invention's effect】

(1) Electric power can be equally distributed to many output terminals. (2) The phases of both output terminals of each output side strip line can be complementarily and continuously varied. (3) The amounts of changes in the phases of the outputs from the output terminals of the plurality of output-side striplines can be changed simultaneously while being proportional. (4) Therefore, by using it as a feeder for each antenna element of the array antenna, the direction of the main beam of radiation from the array antenna can be continuously changed. (5) Since the distributor having many output terminals and the phase shifter can be integrated, the structure is simple and the cost can be reduced. (6) Since the rotatable range of the rotation coupling conductor can be widened,
The range in which the phase of the signal can be varied is large. (7) Since there is no mechanical contact, noise generation and intermodulation problems can be solved. (8) The shape of the angular characteristic of the vertical plane directivity of the radiation of the array antenna can be changed.

[Brief description of the drawings]

FIG. 1 is a conceptual perspective view of a preferred embodiment of a non-contact type coupling circuit according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a conceptual top view of the rotation coupling conductor and the output-side strip line of FIG. 1;

FIG. 5 is a return loss characteristic diagram of an example of the non-contact type coupling circuit of FIGS.

FIG. 6 is a graph showing the passage loss characteristics of the same non-contact type coupling circuit as in FIG. 4;

FIG. 7 is a conceptual top view of a rotating conductor and an output-side strip line according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Dielectric substrate 2 Conductive film 3 Input side strip line 3a Input terminal 3b Input side strip line coupling part 3c Second load impedance circuit 4A, 4B, 4C Output side strip line 4Aa, 4Ab, 4Ba, 4Bb, 4Ca, 4Cb Output Terminal 5 Insulator thin film 6 Rotation coupling conductor 6A, 6B, 6C Arm 6a Input coupling 6Ab, 6Bb, 6Cb Output coupling 6Ac, 6Bc, 6Cc Wider portion 6Ad, 6Bd, 6Cd First Load impedance circuit 6Ae, 6Be, 6Ce Quarter-wave λ transformation circuit

──────────────────────────────────────────────────続 き Continuing on the front page (72) Yuko Saito, Inventor 3-3-1 Marunouchi, Chiyoda-ku, Tokyo Inside Electric Co., Ltd. (72) Masayoshi Serizawa 3-3-1 Marunouchi, Chiyoda-ku, Tokyo Electric Kogyo Co., Ltd. (72) Inventor Hirokazu Tsunoda 3-3-1 Marunouchi, Chiyoda-ku, Tokyo Inside Electric Power Industry Co., Ltd. (72) Inventor Yoshio Ebine 2-10-1 Toranomon, Minato-ku, Tokyo NTT (56) References JP-A-6-326501 (JP, A) JP-A-9-214211 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01P 1/10-1/195 H01P 5/12 H03H 7/20

Claims (4)

(57) [Claims] 1. A dielectric substrate, a conductor film covering a lower surface of the dielectric substrate, an input stripline provided on an upper surface of the dielectric substrate and having an input terminal at one end, and A rotatable coupling conductor rotatable about the other end of the input stripline and having one end coupled to the input stripline via an insulator, and an arc-shaped conductor centered at the other end of the input stripline. A non-contact type coupling circuit having an output terminal at both ends and an output side strip line coupled to the other end of the rotary coupling conductor via an insulator, comprising a plurality of the output side strip lines. , comprising a plurality of arm portions which the rotary coupling conductor extends radially from the rotation center, coupled with the input-side strip line the rotation center of the rotary coupling conductor via an insulator , When the leading end portion of each arm portion is bonded to the respective output-side strip line through an insulator, a wavelength corresponding to the operating frequency and lambda] g, for each arm of the rotary coupling conductor, the output side At the end of the arm connected to the stripline
At the position of λg / 4 from the end,
Forming a wide wide portion, a first load impedance circuit provided in a section from the wide portion to the tip end portion ,
The characteristic impedance from the center of rotation of the rotary coupling conductor to the first load impedance circuit is Z _IN , the equivalent characteristic impedance of the first load impedance circuit is Z ₀ , and the first load impedance is the output side from the first load impedance. Assuming that the impedance looking at the strip line is Z _L , Z ₀ substantially satisfies the relationship of Z _IN Z _L = Z ₀ ² , and λg from the other end of the input side strip line coupled to the rotary coupling conductor. A second load impedance circuit is provided in a section from the point / 4 to the other end of the input-side stripline, and a characteristic impedance in a section from the input terminal to the second load impedance circuit is Z ₁ , an equivalent characteristic impedance of the second load impedance circuit Z _0, the above said input strip line When the impedance seen on the output side from the edge and Z _2, the non-contact type coupling circuit, characterized in that to satisfy the relation of Z ₀ is approximately ^{_{Z 1 Z 2 = Z 0 2}} . 2. A shape is formed on each of said arms of said rotary coupling conductor.
The non-contact type coupling circuit according to claim 1, wherein the wide portion to be formed is a circularly wide portion . 3. A according to claim 1, wherein said second load impedance circuit is formed by increasing the width of the line from the other end of the lambda] g / 4 intervals of the input-side strip line Non-contact type coupling circuit. By wherein adjusting the width of said at least a rotating coupling conductor from the input end of one arm of the lambda] g / 4 sections lines, this to the quarter of the λ transformer circuit is formed < The non-contact type coupling circuit according to claim 1, wherein: