JP2607683B2 - Waveguide circuit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide circuit for power combining two orthogonally polarized electromagnetic waves, and for example, receives two orthogonally polarized electromagnetic waves. It is used as a waveguide feed circuit for a possible planar antenna.

[Prior Art] Conventionally, for example, a feeder circuit of a planar array antenna that receives electromagnetic waves of two orthogonal polarizations is configured by a strip line, and the electromagnetic waves of each polarization are combined by the strip line. However, the stripline has a problem that transmission loss is large and the reception performance of the planar array antenna is deteriorated by the loss.

[Problems to be Solved by the Invention] Therefore, it is conceivable to configure a feed circuit of the planar array antenna with a waveguide circuit. In this case, it is necessary to provide a feed circuit using two series of waveguides corresponding to each polarized electromagnetic wave output from each antenna element in the planar array antenna. For this reason, the configuration of the power supply circuit becomes very complicated three-dimensionally, which leads to an increase in product cost and a problem of impairing the flatness of the planar array antenna.

The present invention has been made in view of such a point,
An object of the present invention is to provide a waveguide circuit capable of achieving power combining of two orthogonally polarized electromagnetic waves on the same plane using a series of waveguides.

[Means for Solving the Problems] In a waveguide circuit according to the present invention, in order to solve the above problems, as shown in FIG. 1, a power combining circuit constituted by a rectangular waveguide And a pair of electromagnetic wave input terminals
A pair of L-shaped bends 1 are provided in the vicinity of A and B for converting the propagation direction of the input electromagnetic wave into opposing directions in the same plane, and the pair of electromagnetic wave inputs propagating in the opposing directions in the plane. A T-branch 2 is provided for combining electric power with electromagnetic waves in orthogonal propagation directions in a plane. The distance from each L-bend 1 to the T-branch 2 is λg / 2, where λg is the waveguide wavelength of the waveguide. Only the difference.

[Operation] In the present invention, a pair of L-shaped bends 1
Is different from the T-shaped branch 2 by λg / 2, the power of the electromagnetic waves propagated by the two polarizations orthogonal to each other in the waveguide is synthesized for each polarization. Power combining of two polarized electromagnetic waves can be achieved by one waveguide circuit.

FIG. 1 is a perspective view of a waveguide circuit according to one embodiment of the present invention. The fundamental mode of the rectangular waveguide used in the waveguide circuit is a TE ₁₀ mode. For convenience of explanation, in FIG. 1, to the polarization of the TE ₁₀ mode shown by the solid arrows, the polarization indicated by the dashed arrows TE ₀₁ mode.

This waveguide circuit is used, for example, as shown in FIG. 4, as a parallel feed circuit of a planar array antenna 3 capable of receiving two polarized waves, that is, a horizontally polarized wave and a vertically polarized wave. Individual antenna elements 4 in planar array antenna 3 shown in FIG.
Consists of a waveguide aperture antenna capable of receiving horizontal polarization indicated by a solid line and vertical polarization indicated by a broken line. Therefore, the first
In the waveguide circuit shown in the figure, the polarization indicated by the solid arrow and the polarization indicated by the dashed arrow are input to the electromagnetic wave input terminals A, B, C, and D.

In FIG. 1, the L-shaped bend 1 provided at the electromagnetic wave input terminals A and B has an H surface (see FIG. 3A) with respect to a TE ₁₀ mode electromagnetic wave indicated by a solid arrow. It acts as an L-shaped bend (H corner) of a plane parallel to the magnetic field. Therefore, the electromagnetic wave changes its transmission direction due to the L-shaped bend,
The planes A 'and B' vibrate in the same phase as shown. In this manner, when the TE ₁₀ mode electromagnetic wave whose propagation direction is changed in the direction along the back surface of the planar array antenna by the L-shaped bend 1 is power-combined in the direction along the back surface of the antenna by the T-shaped branch 2, In this case, an E-plane branch as shown in FIG. 2B is used. Here, when the E-plane branching is used, two electromagnetic waves to be synthesized (in the figure,
) Requires the phase to be inverted in the T-branch 2. Therefore, the point P constituting the first T-shaped branch 2 shown in FIG. 1 is λg / point from a point equidistant from the A ′ plane and the B ′ plane.
4 points have been shifted. Therefore, a difference of λg / 2 occurs between the distance between A′-P and the distance between B′-P,
A 'plane and B' plane in the electromagnetic wave of the TE ₁₀ mode was in phase becomes a reverse phase in the point P, E shown in FIG. 2 (b)
It is combined into one electromagnetic wave (in the figure) by the surface branch.

On the other hand, for electromagnetic waves in TE ₀₁ mode shown by the dashed arrows, the electromagnetic wave input terminal A of FIG. 1, L-type bends provided in the B, as shown in FIG. 3 (b), E plane ( It acts as an L-shaped bend (E corner) of a plane parallel to the electric field. Therefore, the electromagnetic wave changes its transmission direction due to the L-shaped bend,
The planes A 'and B' vibrate in opposite phases as shown. In this manner, when the TE ₀₁ mode electromagnetic wave whose propagation direction is changed in the direction along the back surface of the planar array antenna by the L-shaped bend 1 is power-combined in the direction along the back surface of the antenna by the T-shaped branch 2, , H-plane branching as shown in FIG. 2 (a) will be used. Here, when the H-plane branch is used, two electromagnetic waves to be synthesized (in the figure,
) Requires that the phases coincide in the T-shaped branch. As described above, the point P forming the first T-shaped branch 2 shown in FIG. 1 is a point shifted by λg / 4 from a point equidistant from the A ′ plane and the B ′ plane. Therefore, A'-P
Since the difference between the lambda] g / 2 to the distance between the distance and B'-P between occurs, the electromagnetic wave of the TE ₀₁ mode which was the opposite phase A 'plane and B' plane, in phase in the point P, the 2A single electromagnetic wave (in the figure) is synthesized by the H-plane branch shown in FIG.

Further, as shown in FIG. 1, the power of the TE ₁₀ mode and TE ₀₁ mode electromagnetic waves input from another pair of electromagnetic wave input terminals C and D is combined at the point Q, and the points P and Q are opposed to each other. A second T-shaped branch 5 is formed at a point R on the side (inner side) where the light beam flows. At this time, the TE ₁₀ mode electromagnetic wave shown by the solid line
The phase is reversed at P and Q, and the electromagnetic wave in TE ₀₁ mode indicated by the broken line
P and Q are in phase. Therefore, by forming the T-shaped branch 5 point P, from Q to point R are equidistant, as E-plane branch to electromagnetic waves of TE ₁₀ mode, the H face branch for electromagnetic waves in TE ₀₁ mode Acting, power is simultaneously synthesized for both modes of electromagnetic waves. As a result, for a four-element planar array antenna as shown in FIG.
A power supply circuit for two polarized electromagnetic waves can be constituted by a single-system waveguide circuit.

FIG. 5 is a schematic configuration diagram of another embodiment of the present invention. In this embodiment, a waveguide circuit as shown in FIG.
A third T-shaped branch 6 is provided at a point S on the opposite side (inner side) of the second T-shaped branch in each waveguide circuit. The point S where the third T-branch 6 is provided is located at an equidistant distance from the second T-branch 5 in each waveguide circuit. Therefore, at the point S, the electromagnetic wave in the TE ₁₀ mode is in the opposite phase and the electromagnetic wave in the TE ₀₁ mode is in the same phase, and the third T-shaped branch 6 acts as an E-plane branch and an H-plane branch, respectively, and the electromagnetic waves in the two modes are transmitted. Power can be combined at the same time.
Thus, for an eight-element planar array antenna, a feed circuit for two orthogonally polarized electromagnetic waves can be configured with one system of waveguide circuits.

Further, two sets of waveguide circuits as shown in FIG. 5 are provided, and a fourth T-shaped branch is provided at an intermediate point on the opposite side (inside) of the third T-shaped branch in each waveguide circuit. Is provided, 16
A waveguide feed circuit for a planar array antenna of elements can be configured. Hereinafter, similarly, a waveguide feeding circuit for a ²ⁿ element (n ≧ 5) planar array antenna can be configured. In this case, the number of T-type branches required is (2 ⁿ -1).

[Effects of the Invention] The present invention relates to a power combining circuit using a rectangular waveguide, in which an L-shaped bend provided near a pair of electromagnetic wave input terminals causes input electromagnetic waves to propagate in opposite directions in the same plane,
The pair of input electromagnetic waves are power-combined by the T-shaped branch in the direction of propagation orthogonal to each other in the plane, and the distance from each L-bend to the T-shaped branch is made different by a half wavelength in the waveguide. There is an effect that two polarized electromagnetic waves can be combined in power on the same plane by one system of rectangular waveguide.

In addition, there is an effect that a ^2n- branch power combining circuit can be configured by connecting a plurality of similar waveguide circuits by T-shaped branches.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, and FIG.
(B) is an explanatory view of the operation of the T-type branch used in the above, FIGS. 3 (a) and 3 (b) are operational explanatory views of the L-type bend used in the above, and FIG. FIG. 5 is a perspective view of an array antenna, and FIG. 5 is a schematic configuration diagram of another embodiment of the present invention. 1 is an L-shaped bend, 2 is a T-shaped branch, and A and B are electromagnetic wave input terminals.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kuya Tsukamoto 1048 Oaza Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (56) References JP-A-62-58706 (JP, A) 181003 (JP, U) JP34-6816 (JP, B1)

Claims (3)

(57) [Claims] 1. An electric power combining circuit comprising a rectangular waveguide, wherein L-shaped bends for converting a propagation direction of an input electromagnetic field into opposing directions in the same plane are provided near a pair of electromagnetic wave input terminals. A T-branch for power combining the pair of electromagnetic wave inputs propagated in opposite directions in the plane with electromagnetic waves in propagation directions orthogonal to each other in the plane; The waveguide circuit is characterized in that the distance to the waveguide differs by half a wavelength in the waveguide. 2. A waveguide circuit comprising a pair of waveguide circuits according to claim 1, wherein each electromagnetic wave output from a T-shaped branch in each waveguide circuit is propagated in opposite directions in said plane. A second T for arranging tube circuits and combining powers of electromagnetic waves output from the respective waveguide circuits in orthogonal propagation directions in the plane.
A waveguide circuit comprising a mold branch, wherein the second T-branch and the T-branch of each waveguide circuit are arranged at an equal distance. Wherein ^the 2 ⁿ a waveguide circuit according to claim 2, wherein (n is 1
(The above integer), and a T-shaped branch (2 ⁿ −) for power combining electromagnetic waves output from the 2 ⁿ waveguide circuits in the plane.
1) A waveguide circuit comprising: