JPH03238904A - Plane high-frequency antenna for circularly polarized wave - Google Patents

Abstract

PURPOSE: To obtain a planar antenna that is specially simple to realize by specifying a propagation line and its length. CONSTITUTION: Each horizontal line (LH) has the length between two planes which is equal to λ/2+iλ with i=0, 1, 2,..., and each vertical line (LV) has the length that is equal to λ/2+jλ with j=0, 1, 2,.... Each line LSH has the length that is equal to λ+Kλ with K=0, 1, 2,..., and each line LSV has the length that is equal to λ+1λ with 1=0, 1, 2,.... Points H and V are advantageously selected at the same corner of a parallelogram, and then, a single line (HDGV) passes through two connecting points D and G which are positioned so that GH-GV=λ/4+mλ/2=DV-DH with m=0, 1, 2,..., and connects those points. Thereby, a simple plane antenna is acquired.

Description

TECHNICAL FIELD The object of the invention is a receiving and/or transmitting planar antenna comprising a plurality of radiation plates (PPR') for circularly polarized radio frequency waves, comprising: The radiating plates are dimensioned and adapted to the preferred frequency from the possible frequency range, each plate having four points (N, S) around it located as cardinal painting.

E, O), the above circularly polarized wave is equivalent to two linearly polarized quadrature waves (OH and OV) with the same amplitude and quadrature phase, and the very high frequency signal is and/or S or E and/or O, said radiating plate being located within a parallelogram, and said microwave signal of said preferred frequency being present on each plate; The waveguide length (waveguid
e length) or not interconnected by multiple propagation lines.

This type of antenna is TDFI, TDF2. T
VSAT.

It is particularly intended for the reception of television signals by high power satellites such as...

BACKGROUND ART An antenna of this type is described in the PCT patent application published in Wo 89102662, and this prior art antenna comprises a propagation line and supports simultaneous reception of clockwise and counterclockwise polarized waves. It has a connection mode that it does not allow. Furthermore, if a satisfactory gain is to be achieved, difficulties in implementing the propagation line and output connections will be encountered.

(Disclosure of the Invention) The antenna according to the present invention is characterized in that the plurality of lines are a first set of horizontal lines (LH) connecting each of points E and O, which are located opposite to each other, Each line is i=o, 1.2. a second set of vertical lines (LV) connecting each of the points N and S located opposite to each other, having a length equal to λ/2+i λ, Each line has i =0.1.2. ...with a length equal to λ/2+iλ, the third of the line (LSH) realizing each series connection of points O or E located on the same side of the parallelogram A set of single points (H
) in order to collect the energy added by the first set of lines (LH) at each line K = 0.1.2.・
...has a length equal to or equivalent to λ+, and the point (H) is located near one corner of the parallelogram, or is located on the same side of the parallelogram. A fourth set of lines (LSV) realizing each series connection of points N or S, where at a single point (V) a line (LV)
λ+lλ, where each line is l=o, 1°2,... to collect the energy added by the above second set of
, and the above point (V) is chosen near the same corner of the parallelogram as the above point (H), the above two points H and V a single line (HDGV) connecting, and which m=0.1.2.・
...is a song-■=λ/4+mλ/2=■-, and
Therefore, two connection points are located such that a signal with a clockwise circularly polarized wave is completely present at point G, and a signal with a counterclockwise circularly polarized wave is completely present at point G. and passing through point G.

Thus, a judicious choice of the propagation line and its length results in a planar antenna that is particularly simple to realize. line,
There are no restrictions on the shapes of the plates and parallelograms.

In order to constitute an elementary radiating cell that can be used for clockwise and/or counterclockwise circularly polarized waves according to whether the connection point and/or G is connected or not, the above parallelogram is a square with plates, each plate arranged so that its sides extend parallel to the sides of the parallelogram, and the lines of the first and second set above are i=j='0'. Preferably, it is a planar antenna, having a straight line of length λ/2 such that the other propagation line has a length such that k=l=m=-rOJ.

This type of basic radiating cell constitutes a preferred embodiment considering the minimum surface using maximum gain.

In order to increase the gain, the present antenna comprises groups of the above two elementary radiating cells used for the same circular polarization,
The two radiating cells are geometrically rotated 90° with respect to each other,
and their connection points are advantageously physically arranged opposite to each other with respect to the connection of the common output (SC) formed by the two propagation lines differing in length by λ/4. It is.

In this way, gain is increased and polarization purity is improved.

To further increase the gain, the planar antenna was geometrically rotated by 180°.
the two common outputs are of length λ/2 for single access.
are connected to each other by propagation lines.

Due to this arrangement, the cross-component of the radiation plate is significantly attenuated.

Finally, it is possible to realize a planar antenna comprising a set made up of the above four subsets fed in pairs in opposite phases.

In this way, the radiation of the propagation line is attenuated, which increases the gain until an antenna is obtained with dimensions that are largely commercially available to the masses.

In fact, this type of flat antenna is realized by microstrip line technology and consists of three layers: a conductive layer constituting the emitting surface, deposited by copper strip etching or by screen printing with conductive ink; has a dielectric substrate layer associated with the selected frequency band; a ground plate whose thickness is sufficient to ensure mechanical rigidity and mounting of the antenna;

The invention can be easily understood by means of non-limiting examples illustrated in the drawings.

(Example) All the drawings to be described hereinafter only show the radiation surface flat plate made of a conductive layer and the propagation line. Connection techniques for other layers and signal processing modules are standard. It should only be observed that the adaptation of the dimensions of the plate and the length of the propagation line depends on the electrical properties of the various eyebrows, more particularly on the dielectric layer, constant permittivity, loss tangent, etc.

Therefore, the length of the wavelength of the microst 3) tube line, ultimately denoted "λ", cannot be directly expressed as a function of the wavelength in air of the preferred frequency.

In all these drawings, elements having the same function are defined as being the same.

In FIG. 1, the parallelogram (PPR) formed by the radiating plate (PR) is represented by a dashed line, and the flat plate represents the propagation line LV, which constitutes an antenna of undetermined dimensions.

connected by LH, . . . , the parallelogram need not be rectangular and its sides need not be equal in terms of the number of plates and the dimensions of the line, and the line itself need not be straight.

This general purpose antenna is intended for receiving (and/or transmitting) high frequency circularly polarized waves. The circularly polarized wave is 2
equivalent to two linearly polarized orthogonal waves.

Each plate (PR) has four azimuth starting points (N, S, E.

O), where these different waves appear.

A first set of horizontal lines (LH) connects mutually opposite points E and O on two adjacent plates, and a signal is applied to the ends of each line, e.g. points H1, H2, . exist. For these signals that should be in phase, each line (LH) has i=o, l, 2. ...is λ/2+
It is essential to have a length between the two plates equal to iλ. The choice of possible curvatures of "i" and line (LH) determines the dimensions of the parallelogram.

In a similar manner, a second set of vertical lines (LV)
Points N and S, which are opposite to each other on adjacent plates, are connected, and signals are transmitted, for example, to points v1 and V2. ... exists at the end of each line. Each line (LV) has a length equal to λ/2+jλ, where j=0.1°2,..., and rjJ is "i"
does not need to be equal to .

A third set of lines LSH connects the points H2, . . . in series with each other. In Figure 1, point old, H
2, . . . are located at the same spot as point O on the flat plate located on the side of the parallelogram. Each line LSI is equal to 0. 1.2. ... has a length equal to λ to λ0. The purpose of these lines LSH is to collect the signals present at the ends of the lines Ll at a single point (point H in FIG. 1).

Similarly, with the fourth set of lines LSV, the signals present at the ends of the lines LV are collected at point V. Each line LSV is l=0.1.2. ... has a length equal to λ+lλ.

Points H and V are advantageously chosen at the same corner of the parallelogram, so that a single line (HDGV) m=o, 1.2. - A song that is -■=λ/4+mλ/2=■- connects these points through two connecting points located like a ding and G.

Thus, at the receiving end, the clockwise circularly polarized wave exists at point G, and the counterclockwise circularly polarized wave exists at point G. The connection between standard signal processor modules is realized between the ground plate and the dot or point G (or two at the same time). It is clear that it is the same as transmitting clockwise or counterclockwise polarized waves or both. In all these cases, the connection is fixed and does not need to be modified or even cut off from time to time.

Figures 2a, 2b, 2c and 2d represent modifications of the antenna of Figure 1. To simplify the representation, we assume that each variant comprises only four radiating plates and that the propagation lines are shown, at the same time a minimum value, i.e. 1 = j = l = m = O. However, these values are clearly not limiting.

Figure 2a is actually the same as Figure 1 with only four plates.

Figure 2b differs only in the position of the square plate. Therefore, the points N, S, E, O are no longer found in the middle of the sides, but only in the corners, and in all these cases the points N, S, E, O are located on the periphery as azimuthal origin.

In Figure 2c, the radiation plate is round and the rest is unchanged.

In FIG. 2d, a transformation of the lines LSH and LSV relative to FIG. 2a is introduced, so that points H and V are no longer confused with points O and S of the corner plate. This position favors the "aering" of the etching of the propagation lines. To glue the third and fourth sets of lines, the following relationship n+ -ITRO=/1=VVl-VVO, etc. It is clear that ・ is held.

The antenna represented in FIG. 2a forms a preferred embodiment, on the basis of which the antennas of the following figures are realized; however, this - without forming any constraints, the antenna 2a
is named the elementary radiation cell.

The antenna of FIG. 3 comprises two elementary radiating cells and a radiating surface to increase the gain. Each connection point D1 and D2 is connected to a common output SC from a propagation line number having a length such that
connected, with the two cells at 90° to each other.
``It takes into account that it is geometrically rotated. In fact, it is advantageous to position the two elementary radiating cells so that points D1 and D2 are closest to each other in order to avoid too long propagation lines and improve the polarization purity in the signal output SC.

The antenna of FIG. 4 comprises two groups, thus geometrically rotated by 180°, and whose common outputs SCI and SC
2 are connected by a propagation line of length λ/2.
One of the diagrams has only a single access, in this case designated as SC2. This arrangement of antennas makes it possible to attenuate the cross-component of the radiating plate while increasing the gain.

The antenna of FIG. 5, like the antenna of FIG. 4, comprises four subsets, each of which has a single access ACI.

AC2, AC3, AC4 are supplied in pairs in opposite phases by propagation lines arranged to realize the antenna connection by point NEX.

The antenna of FIG. 5 is suitable for clockwise polarized waves because each elementary radiating cell is connected by its D point.

The antennas in Figure 6 are completely equal, but this time point G
Suitable for counterclockwise polarized waves because only the

The antenna of FIG. 7 comprises four elements as represented in FIG. 5, with a single output (VS) found at the center of the antenna.

The antenna of FIG. 8 has a similar structure based on the antenna of FIG.

As shown, the antenna of FIGS. 7 and 8 comprises 16×16=256 radiating plates connected to the output (VS) by the propagation lines described above.

As a non-limiting numerical example, the antenna in Figure 7 is a satellite TDF.
Tests have shown that it is suitable for I. The satellite transmits at a frequency of 12 GHz, which corresponds to an airborne wavelength of 25 mm. For an antenna whose substrate has a thickness of 1.6 mm and a dielectric constant of 2.2 with respect to air, the propagation line has a waveguide length "λ" of about 19 mm, and the square plate has sides of about 8 mm. However, the result is a square plate antenna with sides of about 300 mm.

The image quality obtained by an antenna is often evaluated numerically by the C/N (carrier/noise) ratio measured at the output of the frequency converter associated with the antenna, and the above antenna has been shown to be the best for satellite TDFI. ie, with a frequency converter facing it and having a noise figure of 1.6 dB, C/N ratios of around 15 dB have been obtained in the center of France on a sunny day.

[Brief explanation of drawings]

FIG. 1 represents an antenna according to the invention, and FIG. 2a, 2b,
Figures 2c and 2d represent a variant of the antenna with 4 radiating plates, Figure 3 represents an antenna with 8 plates with clockwise polarization, and Figure 4 shows a variant with 16 plates with clockwise polarization. Figure 5 represents an antenna with 64 plates with clockwise polarization; Figure 6 represents an antenna with 64 plates with counterclockwise polarization; Figures 7 and 8 represent an antenna with 256 plates. F(G, 1 FIG, 2a FIG, 2c FIG, 2b FIG, 2d FIG, 5 \t FIG, 7 F(G, 8

Claims (1)

[Claims] 1. A plurality of radiation plates (P
A receiving and/or transmitting planar antenna comprising a receiving and/or transmitting planar antenna (PR), wherein said radiating plate is dimensioned and adapted to a preferred frequency from the possible frequency range, each plate having four points ( N, S, E, O), the above circularly polarized wave is equivalent to two linearly polarized orthogonal waves (OH and OV) with the same amplitude and orthogonal phase, and the very high frequency signal is and/or S or E and/or O, said radiating plate being located within a parallelogram, and said microwave signal of said preferred frequency being present on each plate; Either interconnected or not interconnected by a plurality of propagation lines propagating with a waveguide length equal to "λ", said plurality of lines - at a point E located opposite each other; and a first set of horizontal lines (LH) connecting each of the points O, each line having a length equal to λ/2+iλ with i=0, 1, 2, . . . − A second set of vertical lines (LV) connecting each of the points N and S located opposite to each other, each line having i=0, 1, 2, . - a third set of lines (LSH) realizing each series connection of points O or E located on the same side of the parallelogram, with a length equal to 2+iλ, a single point (H); In order to collect the energy added by the first set of lines (LH) at
= 0, 1, 2, ... having a length equal to or equivalent to λ + kλ, with the point (H) located near one corner of the parallelogram, - a parallelogram A fourth set of lines (LSV) realizing each series connection of points N or S located on the same side of In order to collect the added energy, each line has a length equal to or equivalent to λ+lλ, with l=0, 1, 2,... so that the above point (V) is connected to the above point (
- a single line connecting the above two points H and V (HDG
V) and m=0, 1, 2, ..., @GH@-@GV@=λ/4+mλ/2=@DV@
- @DH@, so that the signal with a clockwise circularly polarized wave is completely present at point D, and the signal with a counterclockwise circularly polarized wave is completely present at point G. A planar antenna, comprising: an antenna that passes through two connecting points D and G that are connected to each other. 2. In the planar antenna according to claim 1, the connection point D
and/or to constitute an elementary radiating cell that can be used for clockwise and/or counterclockwise circularly polarized waves according to whether G is connected or not: - the above parallelogram forms four radiating plates; - each plate is arranged such that its sides extend parallel to the sides of the parallelogram; - the lines of the first and second set are i=j='0';
A planar antenna, characterized in that it is a straight line of length λ/2 such that - said another propagation line has a length such that k=l=m='0'. 3. A planar antenna according to claim 2, comprising two groups of elementary radiating cells as described above used for the same circular polarization, the two radiating cells being geometrically rotated by 90° with respect to each other, and A common output (SC) formed by two propagation lines whose connection points differ in length by λ/4
Planar antennas characterized in that they are physically arranged opposite to each other with respect to the connections. 4. In the planar antenna according to claim 3, 180°
characterized in that it comprises a subset constituted by said two groups which are geometrically rotated, and whose two common outputs are each connected by a propagation line of length λ/2 for single access. A planar antenna. 5. A planar antenna according to claim 4, comprising a set constituted by the four subsets described above fed in pairs with opposite phases. 6. A planar antenna comprising the four sets according to claim 5. 7. The planar antenna according to any one of claims 1 to 6, which is realized by microstrip line technology,
and three layers: - a conductive layer constituting the emissive surface deposited by copper strip etching or by screen printing with conductive ink; - a dielectric substrate layer whose thickness is related to the selected frequency band; - a ground plate whose thickness is sufficient to ensure mechanical rigidity and mounting of the antenna. 8. The flat plate antenna according to claim 7, adapted to a transmission frequency of 8.12 GHz, wherein: - the substrate has a thickness of 1.6 mm and a dielectric constant of 2.2; - the propagation line is about 19 mm; A flat plate antenna, characterized in that: - the square plate has side sides of about 88 mm.