JPS6216602A - Waveguide excitation printed dipole array antenna - Google Patents

Abstract

PURPOSE:To obtain a low loss antenna by coupling successively each dipole element which has been printed, to a magnetic field surface side of a rectangular waveguide at a guide half-wavelength interval. CONSTITUTION:Dipoles 5, 5' which have been printed are fed successively at every guide half-wavelength from a magnetic field surface side of a rectangular waveguide 10 through a microstrip line 3. An earth conductor of the microstrip line 3 is grounded to a magnetic field surface outer wall of the rectangular waveguide through fixing metallic fittings 13. On the other hand, the center conductor is inserted into the inside of the rectangular waveguide 10 from a coupling hole 11 which has been provided in the center of the magnetic field surface and coupled with an electric field. In this way, since the waveguide 10 is used for a feeding line, the loss of a feeding circuit is reduced, and especially, in case of a semi-millimeter wave band, the rectangular waveguide 10 itself becomes small in size, therefore, a small size and a light weight are not deteriorated as a whole and a low loss array antenna can be realized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an array antenna used for wireless communication, and in particular to a half-wave dipole antenna in which the radiating elements of the array antenna are printed on a dielectric substrate, and its use. The present invention relates to a printed dipole array antenna configured with a feeding circuit.

[Conventional technology]

Typically, an array antenna requires a power feeding circuit that feeds power to each radiating element constituting the array at a power ratio and phase appropriate for the purpose. Fig. 14 shows a plan view of a conventional printed dipole array antenna, and Figs. 15 and 16 show a plan view of a conventional printed dipole array antenna.
The figure shows a cross-sectional view of a conventional printed dipole array antenna.

With reference to FIGS. 14, 15, and 16.

The printed dipole array antenna consists of half-wavelength Goupole arrays 5 and 5' which are radiating elements, microstrip lines 3 and 3' which are feeding circuits, and are parallel to each other.

A line 4.4' is printed on one dielectric substrate 1. Therefore, it is generally used for the purpose of being small and lightweight. In Figure 1, 3' is a ground conductor for the center conductor 3 of the microstrip line.

20 is a metal reflection plate, and 21 is a power supply connector.

The reflecting plate 20 is generally placed at a position about 1/4 wavelength away from the half-wavelength Goupole array 5° 5' toward the waveguide.

[Problem that the invention seeks to solve]

The above-mentioned conventional printed dipole array antenna uses microstrip lines 3, 3' and half-wavelength wires as a feeder circuit for supplying power to each half-wavelength antenna 5.5', as shown in FIG. dipole 5.5
It has a power supply circuit composed of parallel lines 4 and 4' that directly excite the power.

In this way, the power supply circuit is micros) IJ tube line 3
．． 3' and parallel line 4.4',
There is a problem that the line length from the coaxial connector 21 to each half-wavelength dipole, especially the length of the microstrip line section 3.degree. 3', is long, and as a result, loss in the power supply circuit increases. This loss is mainly caused by the dielectric loss of the dielectric substrate constituting the microstrip line, and the higher the frequency, the greater the loss per unit length.1For example, as shown in Figures 14 and 15, When attempting to realize an array antenna in which dipole antennas are long and substantially linearly arranged on the same dielectric substrate at high frequencies, loss is a major problem.

The present invention aims to eliminate the above-mentioned problems by exciting each half-wavelength dipole antenna using a rectangular waveguide used as a low-loss high-frequency transmission line, and realizing a low-loss printed dipole array antenna. For example, by taking advantage of the characteristic that rectangular waveguides themselves become smaller at high frequencies of 10 GHz or higher, we will realize a structure that is no different from conventional antennas in terms of size and weight. That is.

[Failure to solve the problem]

The present invention relates to a printed dipole array antenna in which a plurality of dipole elements, each consisting of a half-wavelength Goupole antenna and its feeding circuit printed on both sides of a dielectric substrate, are arranged on the dielectric substrate. , a waveguide-excited printed dipole array antenna comprising a rectangular waveguide for sequentially feeding power to each of the dipole elements, the magnetic interface of the rectangular waveguide having the same number of elements as the array antenna. The coupling holes are provided along the center line of the magnetic surface at intervals of approximately intracanal wavelengths;

The feeding circuit for each of the dipole elements includes parallel lines printed on both sides of the dielectric substrate, and a microscopy IJ tube line connected to the parallel lines.

Only the center conductor of the microstrip line has a coupling portion extending linearly on the dielectric substrate.

Furthermore, the half-wavelength Goupole antenna is constructed by bending the parallel line by about 90 degrees to a length of about 1/4 wavelength in opposite directions on both sides of the dielectric substrate; on the magnetic interface outer wall of the tube approximately parallel to the tube axis of the waveguide.

and is fixed substantially perpendicularly to the magnetic surface, and the coupling portion is inserted into the rectangular waveguide through the coupling hole, couples with the electric field within the waveguide to supply power to the microstrip line, and The present invention is a waveguide-excited printed dipole antenna characterized in that the ground conductor of the strip line is grounded to the magnetic interface outer wall of the rectangular waveguide.

〔Example〕

The present invention will be explained by way of examples.

FIG. 1, FIG. 2, and FIG. 3 are a plan view and a sectional view, respectively, showing one embodiment of the present invention.

Referring to FIGS. 1, 2, and 3, 10 is a rectangular waveguide with 19 as the tube axis, and 11 is approximately A wavelength interval on the center line of the magnetic interface outer wall 18 of the waveguide. The number of coupling holes provided is the same as the number of elements in the array. The coupling hole 11 is formed by a hole sufficiently small compared to the wavelength approximately on the center line of the magnetic interface, or a slit having a longitudinal direction in the tube axis direction on the center line, so that the power in the waveguide does not leak from the coupling hole itself. configured. On the other hand, the dipole elements that are the constituent elements of the array antenna are half-wavelength dipoles 5 and 5'.

Parallel lines 4, 4', microstrip lines 3, 3', and coupling portions 2 are printed on both sides of the dielectric substrate 1. That is, on the first surface of the dielectric substrate 1, a half-wavelength dipole 5. Center conductor of microstrip line 3. A parallel feed line 4 is connected to a half-wave dipole 5' on the second surface, and a ground conductor 3 of a microstrip line. A parallel feed line 4' is printed. The center conductor 3 of the IJ tube line extends linearly downward on the first surface of the dielectric substrate 1.

The connecting portion 2 is formed by this extending portion. Also.

The half-wave dipoles 5 and 5' each have parallel lines 4°4'
It is constructed by bending the wavelengths by approximately 90 degrees in opposite directions to a length of approximately 1/4 wavelength.

Referring also to FIGS. 4, 5, and 6 showing dipole elements, the ground conductor 3' of the microstrip line is located close to the coupling hole on the magnetic interface of the waveguide and parallel to the tube axis 19. It is grounded to the magnetic interface outer wall of the power feeding waveguide 10 via the fixed fitting 13 . On this occasion.

The coupling portions 2 are each inserted into the waveguide 10 through the coupling holes 11, and are coupled with the electric field within the waveguide lo to feed power to the microstrip lines 3, 3'. The amplitude of the power supply mainly depends on the length t of the coupling portion 2 shown in FIG. On the other hand, waveguide 1
Radio waves propagating within 0.

While propagating the length of the tube wavelength (λg), 1 phase is 3
Since it changes by 60 degrees, the excitation phase is mainly adjusted by the spacing between the coupling holes 11.

The radio waves fed to the microstrip lines 3 and 3' are transferred to parallel lines 4 and 4' according to the excitation amplitude and phase at the coupling section 2.
Power is supplied to the half-wavelength dipoles 5, 5' through the . That is,
The radio wave propagating in the waveguide lo excites the half-wavelength dipoles 5 and 5' from the successive coupling section 2.

As a result, the entire printed dipole array antenna on the dielectric substrate 1 is fed with power.

In this case, each half wavelength Gui? - The loss in the power supply system for feeding the cables 5 and 5' is waveguide propagation loss, micros) I
For example, in the vicinity of the 10 GHz band, the loss of the unit length of the waveguide is the same as the loss of the microstrip line 3, 3' and the parallel line 4, 4'.
' and the loss per unit length γ of the parallel lines 4, 4'. The loss is as low as /100 to 1/70. Since the trenched microstrip lines 3, 3' and the parallel lines 4, 4' have short line lengths due to the structure of the present invention, the overall loss is low. In addition.

20 shown in Figures 1 to 3 is a Guipole array, approximately 1.
/4 This is a metal reflection plate installed at a distance on the waveguide side, and eliminates the influence of the feeding waveguide and feeding circuit on the radiation characteristics of the array antenna.

It is also used as an image board for the Guipole array.

As described above, the excitation phase of each half-wavelength dipole 5, 5' is adjusted mainly by the spacing between the coupling holes 11. on the other hand,
Control of radiation characteristics of play antenna.

That is, from the point of view of reducing unnecessary radiation in directivity synthesis (so-called dalating lobe suppression), it is difficult to maintain a large spacing between the half-wavelength dipoles 5 and 5', and it is generally ineffective to limit the spacing to about the μ wavelength of the radio waves used. The date is T.

By the way, as is clear from FIG. 1, if the distance between the half-wavelength dipoles 5 and 5' is made slightly smaller.

It is no longer possible to print the half-wavelength guipole itself on the same dielectric substrate, and in order to print it, it is necessary to devise ways to shorten the guipole length. This device to shorten the Guypole length is not inconsistent with the present invention, but considering that the wavelength in the waveguide is larger than that in free space, the spacing between the coupling holes is set to approximately the wavelength in the guide. Adjustments will be made in the near future. Therefore, adjacent half-wavelength dipoles 5,
5' are excited in substantially opposite phases to each other in the coupling portion 11.

In order to compensate for the above-mentioned out-of-phase excitation, adjacent half-wavelength guides are used as shown in FIG. - the wheels 6, 5' in the same direction (extending 180 degrees in opposite directions);

The phase is inverted using these half-wavelength dipoles 5 and 5'.

Therefore, it is possible to feed the half-wavelength dipoles 5, 5' adjacent to each other in the same phase. In FIG. 1, when it is desired that the maximum radiation direction of each half-wavelength dipole 5, 5' be aligned from the back to the front of the page.

Each half-wavelength dipole 5, 5' must be fed with power in the same phase. Therefore, the method described above is effective in such cases.

In the embodiment shown in FIG. 7, a phase inversion effect similar to that described above is achieved using a microscoil (IJ) tube line of a power supply circuit. The half-wave dipoles 5 are printed in the same direction (to the right), and the half-wave dipoles 5' are also printed in the same direction (to the left).

Then, the line length of the microstrip lines 3, 3' is bent by forming a bending part 7 on only one of the microstrip lines 3, thereby lengthening the microstrip line 3 by half the propagation wavelength and inverting the phase.

Other embodiments of the present invention are shown in FIGS. 8, 9 and 10, respectively. In the embodiments of FIGS. 8 and 9, the waveguide 10
The purpose is to reduce unnecessary radiation from the coupling hole 11 of the microstrip line 3.3' or unnecessary radiation from the microstrip line 3.3', and to efficiently supply power from the coupling part 2 to the microstrip line 3.3'13). There is. In the embodiment shown in FIG. 8, a U-shaped grooved metal body 14 having a groove depth of about 1/4 wavelength in a direction parallel to the magnetic interface is provided on the outer wall of the magnetic interface of the waveguide 10 having the configuration shown in FIG. It was added. The number of grooved metal bodies 14 is ≠4 consecutively in the tube axis direction. The grooved metal body 14 utilizes a so-called choke function.

The grooved metal body 14 has a function of preventing unnecessary current from flowing from the coupling hole 11 to the outer wall of the waveguide and unnecessary radiation.

In the embodiment shown in FIG. 9, a micro wire (micro wire) of the feeder circuit is attached to the side of the IJ tube line 3), and a new dielectric plate 1' with a metal plate 3'' is attached to the fixing metal fitting 13'.
It is provided using a so-called triplate type (three-layer structure). This triplate shape reduces unnecessary radiation from the microstrip line itself in a direction perpendicular to the dielectric plate 1.

In the embodiment shown in FIG. 10, the microstrip line 3,
3' to the parallel lines 4, 4' efficiently.
Microstrip lines 3, 3' and parallel glands 4, 4'
The aim is to reduce unnecessary radiation from
A U-shaped grooved metal body 15 having a groove depth of approximately 1/4 wavelength and extending perpendicularly to the magnetic interface of the waveguide is disposed on both sides of the printed board on the magnetic field outer wall surface of the waveguide. . One grooved metal body 15 is micros) Ground conductor 3' of IJ tube line
On the other hand, the other grooved metal body 15d is disposed such that its lower end coincides with the outer edge of the coupling hole 11.

These grooved metal bodies 15 are continuous in the tube axis direction. This grooved metal body 15 adds a choke function to the exchange portion (connection portion) between the microstrip lines 3, 3' and the parallel lines 4, 4'.

FIG. 11 shows another example of the configuration of the metal reflecting plate used in the embodiments shown in FIGS. 1 to 3.

This metal reflecting plate 22 has a slit 23 in the center thereof extending in the tube axis direction into which the dielectric substrate 1 can be inserted. The metal reflecting plate 22 is bent to have a U-shaped cross section. I211, first and second wall plate surfaces 22b+22c are formed that extend upward from the long side end of the first plate surface 22a in which the slit 23 is formed, and this metal reflecting plate 22 extends in the tube axis direction. Extending. When this metal reflection plate 22 is used, the metal reflection plate 2
By the first and second wall plate surfaces 22b and 22c of 2,
The first and second wall surfaces 22b viewed from the half-wavelength dipole
, 22c, and reflects the energy in the front direction. This reflected wave and the direct wave from the half-wavelength dipole are combined to form a beam. That is, the radiation characteristics in a plane orthogonal to the dielectric substrate 1 are shaped by the metal reflecting plate 22 .

1/I 6 a 6' is a folded dipole, and the folded dipoles 6.6' are connected via a through hole 8 to form a folded dipole antenna.

Note that in one or more embodiments, coupling portion 2. Center conductor of microstrip line 3. The line widths of the parallel lines 4, 4' and half-wave dipoles 5, 5', and the line spacing of the parallel lines 4, 4' were all constant, but for impedance matching, they were set in a step shape with 9 rammeters. Alternatively, it may be changed into a chi-g shape.

〔Effect of the invention〕

As explained above, in the printed dipole array antenna according to the present invention, a printed dipole antenna with low loss can be realized by feeding the printed dipole array antenna using a waveguide, and the loss is more significant. If applied to the frequency of the sub-millimeter wave band that appears,
It is possible to realize an antenna with a structure that does not impair the original characteristics of an f IJ integrated array antenna, such as small size and light weight.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIGS. 2 and 3 are sectional views of the embodiment shown in FIG. 1, FIGS. 4 and 5,
and FIG. 6 are a front view, side view, and rear view showing a part of the printed board of the embodiment shown in FIG. 1, respectively, FIG. 7 is a diagram showing another embodiment of the present invention, and FIG. , FIG. 9, and FIG. 10 are diagrams showing a power supply circuit of a printed board used in the present invention, and FIG. 11 is a diagram showing another embodiment of a reflector plate used in the present invention, and FIG. FIG. 13 is a front view and a rear view showing other embodiments of the printed dipole used in the present invention, FIG. 14 is a plan view showing an example of a conventional printed dipole array antenna, and FIGS. 15 and 16. The figure is a sectional view of the printed dipole array antenna shown in FIG. 14. 1.1'...dielectric substrate, 2...coupling part, 3...
Center conductor of microstrip line, 3', 3"・
...Micros) Ground conductor of IJ Tsubu line r 4 +
4'...Parallel line, 5゜5'...Half wavelength dipole, 6, 6'...Folded dipole, 7...Folded F) bent 1/f section, 8...Through hole, 10 ...Waveguide, 11...Coupling hole #13113'...Fixing metal fittings. 14.15... U-shaped grooved metal body, 18... Magnetic interface outer wall of waveguide, 19... Tube axis of waveguide, 20,
22/IQ'1...Reflector, 21...Coaxial connector, 23...Slit.

Claims (6)

[Claims] (1) A printed dipole array antenna in which a plurality of dipole elements are arranged on the dielectric substrate, each of which has a half-wavelength dipole antenna and its feeding circuit printed on both sides of a dielectric substrate; A waveguide-excited printed dipole array antenna comprising a rectangular waveguide for sequentially feeding power to each of the dipole elements, wherein a magnetic surface of the rectangular waveguide has the same number of elements as the array antenna. Coupling holes are provided along the center line of the magnetic interface at approximately 1/2 tube wavelength intervals, while the feeding circuit for each of the dipole elements includes parallel lines printed on both sides of the dielectric substrate; A microstrip line connected to the parallel line, and only the center conductor of the microstrip line has a coupling portion extending linearly on the dielectric substrate, and the half-wavelength dipole antenna connects the parallel line to the dielectric substrate. The dielectric substrate is bent by about 90 degrees to a length of about 1/4 wavelength in opposite directions on both sides of the dielectric substrate. The coupling portion is inserted into the rectangular waveguide through the coupling hole, and is coupled with the electric field within the waveguide to connect to the microstrip line. A waveguide-excited printed dipole antenna for feeding power, wherein a ground conductor of the microstrip line is grounded to an outer wall of the magnetic interface of the rectangular waveguide. (2) In the statement of claim (1), when viewed from one side of the dielectric substrate, the half-wavelength dipole antennas are bent not in the same direction but in opposite directions. A waveguide-excited printed dipole array antenna characterized by a mixture of wavelength dipole antennas. (3) In the description of claim (1), the waveguide is disposed adjacent to the coupling hole of the rectangular waveguide and along the dielectric substrate on the side of the center conductor of the microstrip line. A waveguide excitation printer characterized in that a U-shaped grooved metal body having a groove with a depth of about 1/4 wavelength parallel to the magnetic interface is attached to the outer wall of the magnetic interface of the waveguide. Ted dipole array antenna. (4) In the description of claim (1), there is a depth of about 1/4 wavelength on both sides of the dielectric substrate along the dielectric substrate in a direction perpendicular to the magnetic interface of the waveguide. A waveguide-excited printed dipole array antenna, characterized in that a U-shaped grooved metal body having a groove is attached to the outer wall of the magnetic interface of the waveguide. (5) In the description of claim 1, a space between the half-wavelength dipole antenna and the magnetic interface outer wall of the waveguide extends in a direction perpendicular to the dielectric substrate, and an end portion A waveguide-excited printed dipole array antenna characterized by being provided with a reflective plate bent to face a dielectric substrate. (6) The waveguide-excited printed dipole antenna according to claim (1), wherein the dipole element is constituted by a folded dipole antenna and a feeding circuit.