JPS61109305A - Microstrip type antenna - Google Patents

Abstract

PURPOSE:To form a beam characteristic in an optional direction by dividing a microstrip type flat antenna into plural divisions having a side looking characteristic on an (xz) plane, forming them in a staircase form and obtaining the side looking characteristic on an (xy) plane. CONSTITUTION:Plural antenna elements 1 each formed with a printed board are arranged in a step form and they are supported by a frame 2. Then a branch feeding circuit constituted by using a T branch connector 4 and a coaxial cable 5 is connected to a coaxial connector 3 provided to the end of each antenna element 1 and each element 1 is fed in phase. Then an interfatial distance between the two elements, that is, a step difference D is selected as an integral number of multiple of a spatial wavelength of a transmission/reception wave. Two strip conductors 8a, 8b bent in crank-shape are etched to the surface of a dielectric board on the back side of which an earth conductor 7 is formed in this element 1, and a high frequency current is applied between conductors on the front and back sides from the connector 3 provided to one end of the board. Thus, the antenna having the side looking characteristic on the (xz) plane is split into a step form to obtain the side looking of the (xy) plane.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a microwave antenna using a crank-shaped strip line.

[Background Art 1] An antenna for receiving circularly polarized waves for satellite broadcasting in which a large number of microstrip lines are arranged in a plane has been devised. FIG. 3(,) shows a small example of this, in which a large number of parallel strip lines 8 are bent in a crank shape and are sequentially shifted by half a period. If this crank-shaped basic pattern is configured as shown within the broken line in Figure (b), circularly polarized waves can be emitted (or received) in a direction perpendicular to the surface, and the dimensions of the basic pattern can also be reduced. If one configuration is made so that the same pattern can be seen from the θ direction by stretching in two axial directions, a so-called side-looking type having directivity in the θ direction can be obtained.

Due to the side-looking characteristics mentioned above, microstrip antennas have the advantage of being much less restricted in terms of installation location than parabolic antennas, but this side-looking characteristic is limited to the xZ plane. For example, when mounting on the outside wall of a house, it must be tilted to face the satellite, and consideration must be given to wind, rain, and snow accumulation.

[Object of the Invention] The present invention has been made in view of the above problems, and its object is to solve the problems described above. An object of the present invention is to provide a microstrip type antenna that can have side-looking characteristics not only in the plane but also in the xy plane.

[Disclosure of the Invention 1] The present invention includes a planar antenna formed by periodically bending a large number of parallel strip-knob lines in a crank shape and sequentially shifting them by half a period, each including 2n strip lines. Divided into multiple antenna elements, each antenna element has the spatial wavelength λ of the transmitted and received waves. The structure is arranged in a step-like manner with steps having a length that is an integral multiple of This is how it was done.

FIG. 1 shows an embodiment of the microstrip antenna of the present invention, in which a plurality of antenna elements 1 made of printed circuit boards are arranged in a stepwise manner and are supported by a frame 2. A T-branch connector 4 and a coaxial cable 5 are connected to the coaxial connector 3 provided at the end of the antenna element 1.
A branch power supply circuit 6 configured using
Each antenna element 1 is configured to be fed with in-phase power.

The distance between the surfaces of each antenna element 1, that is, the step difference is the spatial wavelength λ of the transmitted and received waves. (n is a natural number).

The structure of the antenna element 1 is as shown in the same figure (1).
On the surface of the dielectric substrate with the ground conductor 7 formed on the back surface,
Two strip conductors 8a bent into a crank shape,
8b is formed by etching, and a high frequency current in the 12 GHz band is supplied between the front and back conductors from the coaxial connector 3 provided at one end of the substrate. The other end of each strip line 8a, 8b has a characteristic impedance (5
It is terminated with a pure resistor 9 of 0Ω). In this way, each antenna element 1 has two strip lines 8a, 8.
b is provided to suppress side lobes due to mutual interference between the radiated waves from the two strip lines.
7. For applications where the force C1 angle φ, which is required to provide directivity in one plane, is too thick, the width of the antenna element 1 should be widened, and each antenna element 1 should have four or six wires. 2n strip lines 8 may be provided, such as a book.

In addition, in this embodiment, each antenna element 1 is rotatably supported on the frame 2, and the frame 2 itself can freely adjust its inclination angle using a semi-fixed joint. λ. It is more advantageous in terms of cost and reliability to fix the length to an integral multiple of . Alternatively, the step may be fixed and fine adjustment may be made by providing a phase shifter on one strip line of each antenna element.

In the embodiment shown in FIG. 2, the branch power supply circuit 6 is constructed from a printed circuit board 9, and by doing so, the expensive T-branch connector 4 and microwave cable 5 can be omitted.

Furthermore, in order to omit the coaxial connector 3, it is also possible to use a flexible dielectric substrate.

1 Effects of the Invention 1 In the present invention, the conventional microstrip type planar antenna having side-looking characteristics in the ×Z plane is divided into a plurality of parts and formed in a step-like manner.
Furthermore, since it is possible to obtain beam directivity in any direction by imparting side-lucking characteristics to one side, it is possible to mount the beam on the outer wall of a house without tilting it.

[Brief explanation of drawings]

Fig. 1 shows one embodiment of the present invention, (a) is a perspective view, (b) is an enlarged perspective view of the main part, and Fig. 2 shows another embodiment, (a) is a perspective view, (b) is an enlarged perspective view of the main part, and FIG. 3 shows a conventional example, (,) is a perspective view, and (b) is a top view of the main part. 1 is an antenna element, 2 is a frame body, 3 is a coaxial connector, 4 is a T-branch connector, 5 is a coaxial cable, 6 is a branch feeder circuit, 7 is a ground conductor, 8, 8a and 8b are strip lines, 9 is a printed circuit board , D is the step, λ. is the spatial wavelength,
λg is the line wavelength. Agent Patent Attorney Ishi 1) Cho 7 Figure 3 (b) Entered; Enro Keicho Procedural Amendment (spontaneous) March 4, 1985 Patent Application No. 230875 No. 2 of 1988, Title of Invention: Microstrip Type Antenna 3, Relationship with the amended person case Patent applicant address 1048 Kadoma, Kadoma City, Osaka Prefecture Name (58
3) Matsushita Electric Works Co., Ltd. Representative Sadao Fujii 4 Agent postal code 530 Address 1-12-17-5 Umeda, Kita-ku, Osaka City Date of amendment order

Claims (1)

[Claims] (1) A plurality of antenna elements each including 2n striplines (n is a natural number), which is a planar antenna formed by periodically bending a large number of parallel striplines into a crank shape and sequentially shifting them by half a period. What is claimed is: 1. A microstrip type antenna, characterized in that the antenna elements are arranged in a step-like manner with steps having a length that is an integral multiple of the spatial wavelength of transmitted and received waves.