JPS60186102A - Reflecting antenna with buried feedphone - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Field of Industrial Application) The present invention relates to microwave antennas, and more particularly to recessed feedhorn reflector antennas.

(Prior Art) Offset type reflector antennas have aperture disturbance (aperture disturbance).
re -blocking e['fects) When performance is more important than cost because the effect is small,
Non-offset or axially symmetric reflector antennas also tend to be preferred. While an axially symmetric antenna has the feedhorn's vertical axis aligned with the parabolic axis, an offset reflector antenna has the feedhorn's vertical axis offset from the axis of the parabolic antenna dish. It is. In offset reflector antennas, by offsetting the feedhorn from the axis of the parabolic dish, the feedhorn can be moved without blocking the dish aperture.
Live blood can be irradiated. This low aperture disturbance effect is often an important advantage of offset reflector antennas. Aperture obstruction by the feedhorn (11) reduces the effective aperture area of the dish, causing gain loss in the device, (2) generates radiation scattering from the feedhorn itself and the coupling waveguide, and side lobe suppression (11).
・Airborne radio waves are becoming more and more densely packed, and the spurious radiation characteristics of antennas are becoming more and more difficult.
The above-mentioned aperture blocking effect is becoming increasingly important to the military. Since offset type reflector antennas have the effect of reducing the aperture disturbance effect, offset type reflector antennas are often preferred when strict performance characteristics are required.

However, there are several major drawbacks to the Offsela 1-type reflector antenna configuration. One of these drawbacks is
Cross-polarization components (cross-
polarized component). This orthogonal polarization becomes a big problem in the following cases. That is, if the antenna is required to meet strict orthogonal polarization radiation specifications, it becomes necessary to increase the mechanical strength of the tower on which the antenna can be mounted, which increases the cost, so orthogonal polarization becomes a big problem. Furthermore, for structural reasons, offset reflector antennas are more expensive to manufacture than axially symmetric antennas, resulting in a larger and more complex structure.

Design the antenna. In general, the reflector should be set as large as possible for practical use, and then the feed horn should be set to efficiently irradiate the reflecting surface.

Design is typically done to maximize gain or to maximize reduction of side rope levels.

In both axially symmetric and offset reflector antennas, problems with wind loads are inevitable due to the large size of the reflector. The antenna reflector acts like a sail and can bend the antenna when exposed to the wind; to minimize such bending, the antenna's structural strength must be improved by using expensive mounts. It is necessary to increase The above target is 9
If is large, beam clutter will occur and orthogonal polarization irradiation will increase, resulting in a major problem.

(Problems to be Solved by the Invention) The present invention provides an excellent aerial directional line diagram (radiati
It is also an object of the present invention to provide a reflector antenna with a feeding horn that has a reduced wind load factor and has a reduced wind load factor.Other auxiliary objects of the present invention are to: ■ Operate over two frequency bands; ■ Structure The object of the present invention is to provide a reflector antenna with a feed horn that is simple and inexpensive to manufacture.

Other objects and advantages of the invention are set forth in the following detailed description and accompanying drawings.

Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a parabolic reflector and a flat reflector, and further includes a feed horn for illuminating the parabolic dish. It is embedded in a flat reflector to reduce the aperture obstruction effect caused by the feed horn. It is also preferred to embed the entire feedhorn in a planar reflector to minimize aperture obstruction effects.

In the first embodiment, the reflector has a focal length to diameter ratio of approximately 0.6.
The recessed feed horn, which has a 45° circular parabolic plate shape, is free from interference from planar reflectors.
It is now possible to irradiate a parabolic reflector.

Furthermore, in the second embodiment, in order to use the antenna on the ground, a non-circular parabolic reflector is used to form different radiation patterns on the horizontal plane and the vertical plane, thereby narrowing the radiation on the horizontal plane. For the non-circular parabolic reflector, in the vertical and horizontal planes, about 0.833 and about 0.833
It is preferable to have a focal length to diameter ratio of .

It should be noted that the feeding horn used in the present invention preferably has a small aperture in order to further reduce the aperture interference effect.

(Operation) As a result of adopting the above-mentioned means, the feed horn has a annihilation electric field at the edge of its aperture in the upper frequency band to suppress the edge current along the plane reflector surface at the aperture of the feed horn. This prevents the flow of ground plane currents in the planar reflector, which would degrade antenna performance. In that lower frequency band, a feedhorn choke surrounding the feedhorn aperture effectively suppresses edge currents.

(Examples) The present invention will be described in detail below, but the present invention is not limited to these examples, and includes other modified structures and equivalent products as clarified in the claims. It is something that

Figures 1 and 2 show a double-reflection type axially symmetric planar parabolic reflector antenna (axis, ymnetr 1cal”p).
lanar-parabolic re['1ecto
(hereinafter referred to as a reflective antenna) is shown. The reflecting antenna is equipped with a parabolic dish reflector 10 (hereinafter referred to as a blood vessel), a primary feed horn 11, and a flat reflector 13 (!:).The primary horn 11 is attached to the axis of the circular dish 10. A planar reflector 13 is coaxially positioned at an angle of 45° to the axis of blood 10 , coupled to and supported by a circular waveguide 12 extending along the axis of blood 10 .

The axis of live blood 10 is located vertically and coincides with the longitudinal axes of waveguide 12 and feed horn 11 .

Note that the term "fee F" used here has the connotation of use in the transmitting state, but as is generally used in this field, it also includes use in the receiving state.

In the transmitting state, the feed horn 111rim combiner 1
4 and the circular waveguide 12, and emit those signals upward toward the parabolic ball surface 10 as spherical waves. The ball surface 10 reflects the signal as a plane wave downward toward the plane reflector 13, and the plane reflector 13 converts the signal into a plane wave.

It is reflected laterally as a horizontal wave. In the receiving state, the incident planar horizontal wave is irradiated by the planar reflector 13 and its energy is reflected to the live blood 10 . The live blood 10 reflects the incident energy as a sphere 11 wave toward the feedhole 711, and transmits it to the receiver via the circular waveguide 12 and coupler 14.

The diameter of the parabolic live blood 10 is I), and as required for this type of double-reflection antenna, the focal point F of the parabolic surface of the main reflector is at the phase center of the feed horn 11 (usually feed horn opening). In order to be configured in this way, the planar reflector 13 is provided with a central opening, and this opening allows the feed horn 11 to illuminate the ball surface 10 without receiving interference from the surface of the planar reflector 13. The plane reflector 13 is provided at a position where it can block almost all of the radiation waves emitted from the feed horn 11 and reflected by the ball surface 10 in the transmitting state. Since the opening of the fresh blood 10 is circular and the planar reflector 13 is positioned obliquely with respect to the axis of the fresh blood 10, the shape of the planar reflector 13 is elliptical. Since the plane reflector 13 is inclined at an angle of 45° with respect to the axis of the ball skin 10, the vertical radiation wave from the blood 10 changes its direction to the horizontal direction.

In the receiving state, the incident horizontal radiation wave is redirected by the planar reflector 13 in a vertical direction to illuminate the hemostat 10 .

A cylindrical housing 15 is provided to support the live blood 10, the planar reflector 13, and the feed horn 11 at desired positions i. In the illustrated embodiment, an aperture 16 is provided in the cylindrical housing 15 to allow the radiation waves to enter the cylindrical housing 15 of the antenna and illuminate the planar reflector 13. Since the plane reflector 13 is tilted at an angle of 45° with respect to the axis of the ball surface 10 having a parabolic surface, the leakage direction≠
5 Main ■ Horizontal heat path perpendicular to the axis of 10) 1 to irradiate 10 in the best condition. For this purpose, a cylindrical shield 30 or d: with an absorbing material pasted around the opening 16 of the circumferential housing 150 is provided, and a
It is designed to reduce the deviation of incident radiation waves. Shield 30; ring-shaped series of genus and kutus fibers'+
' + Consisting of a protruding body, whose inner and outer walls are horizontally irradiated, and ll? -j is preferable. As the microwave absorbing material 27, it is possible to use a general material in which the first phase is a rectangular steel shape or a flat or enveloped shape. )Ibsorbcr
) can also be used on the inner surface of the shield 30. A pair of vertical beams 18.1 to support the antenna.
9 and a pair of horizontal beams 20, 21 surround the cylindrical housing 15. Vertical columns and beams 22 are connected to the horizontal beam 21 via orthogonal beams 23. In order to support the antenna on the upper plate 10, the back surface of the live trap 10 is connected to a vertical beam 22 by an L-shaped bracket 24. In order to hold the planar reflector 13 in place, the reflector's Il! +,)′1
1111 &) 1r) beams 25 and 26 are provided. In order to more effectively prevent 11111 direction radiation, an absorbing material 27 (i/i
There is also a provision around Jl,l 10.

As shown in FIG. 3, the feed horn 11 has two truly curved circular wave tubes; It is preferable to configure it by tying it together. Such a feed horn 11 can generate an E blood pattern and an 11-plane pattern with equal I'J, in two different frequency bands. This makes the diameter of the horn aperture approximately equal to the wavelength of the low), +a / This can be achieved by setting it to cancel out. By making the diameter the same as one wavelength in the low frequency band, the pattern of the No. 1 and No. 8 surfaces becomes nearly invisible for low frequency signals, and the inner wall of the horn aperture allows the same wavenumber band to be By canceling the nJ field, j):+i)^
] ? D? The pattern of the E-side and the 1-noi River for the 1st month is almost like a shop. The horn can be manufactured in a small size and at low cost, and coaxially with the horn, the 11-plane ob-beam pattern 'ff- is vague in the image frequency band.

This small size of the horn minimizes horn interference caused by placing the horn in the center of the planar reflector 13.

The portion 40 of the feed horn 11 shown in FIG. 3 has an inner diameter 1 approximately equal to one wavelength at the center frequency of the low frequency band (e.g. 3.95 G 1] 7. ) is a normal 17-sliding wall 1'E, 7-d horn. The inner diameter I)2 of the cylindrical waveguide portion 410 of the feed horn is small, and the height is increased by connecting the cylindrical waveguide portions 40 and 41 with a conical waveguide portion 42 with a uniform taper. In a frequency band (for example, 60 Hz), a 1゛ΔI11 modal portion 4 (1, 42) is generated and propagated at the junction.More specifically, the conical portion 42 is
Niwabe force 1 in small diameter cylindrical portion 41 and portion 42]
Propagates to the m circle from T E + I mode to TΔIl
L Mo 7 G (131, 1 minute 40・42 1 absorption C sound 1
5)). Circular translation: 'J'Δ゛111 generated in the ribs at the end of the shaped part 42
The mode leads the TJs, 1 mode by about 90° phase. i'Ml, the amplitude of the mode signal is the conical part 4
2, and the phase relationship between the two modes at the aperture of the feed horn is determined by the length J of the large diameter portion 4.0.
・Determined by.

By appropriately setting the length L of the circular portion 40 of the feed horn 11, TΔ'
The phases of the I1 and 1'J bow 11 modes can be matched with the foot horn aperture. Also, if the feed horn of FIG. 3 is designed to have a V S W R less than 1.1, excellent in-velocity matching can be obtained. The inner diameter of the pipe 12 connected to the small diameter of the feed horn is the same as the inner diameter of the small diameter cylindrical tube. A pair of 7 runci 43.
44 with a plurality of screws 45, the waveguide 12 and the feed horn are fixed.

In order to suppress back radiation from the outer surface of the horn 11 at low frequencies, the 131" mouth end of the horn or the quarter wave chiyoke 46 is used.
It is surrounded by The choke 4b has a short conductive cylinder 47 concentric with the horn 11 and a short ring 47 of 6tfi. The length of the cylinder 47 is approximately equal to a quarter wavelength from the end of the cylinder 47 (7.1 By shorting 47 to the horn 11 with link 48, a quarter wave coaxial choke is created which suppresses the current on the outer surface of the horn.

In the high frequency band (free space wavelength 1), by canceling the electric field at the aperture boundary, the back radiation is suppressed and equal main beams are obtained in six planes. To achieve this,
Mode power W '1%7. The ratio of □ and WTE, □ is set as follows.

Here, the length of T ill mode is as follows.
/C) 2 (2n-!TJI E, the Sakai wave length in l mode is as follows・”g T h 1□−”H−
IT” Hyakucho σ possible 2 (3) and C:II) l /λH (4) The above mode power ratio, diameter 1) of the large diameter end of the conical portion 42, half-flare angle of the conical portion 42 ( half]
It is known that the relationship between a r c a n g ] c ) β (degrees) is given by the following formula.

Equating equations (1) and (5) yields the following.

In order to generate approximately equal E and T patterns in the low frequency band, the diameter D ], for example, the following equation (
7) in the low-midband frequencies of one wavelength λL
is set almost equal to.

IJ l = -7, J, (7) Therefore, equation (6) becomes as follows, Solving equation (5) for β yields a base 9 value.

This β? In addition, in the high band, the 1 field at the aperture boundary disappears, which causes the E and 11 patterns of the three beats reflected from the pawn at the cylinder frequency (1 to 1) to disappear. or almost equal.

In order to reliably generate TΔill7 at the connection between the 1" month Y warp-shaped portion 4u and the circular button-shaped gls portion 42, C defined as π1)l/λIJ according to equation (4). 1 in the (IIJ or high frequency) range to 1 in 4-eye mode
Is it necessary to set 11-1 diameter 1) 1 so that it is also larger than 8.83? Ill IL, in order to ensure that only the l mode is generated, the diameter is set to 1 so that the eigenvalue in the C region or the high frequency band is smaller than the eigenvalue of 5.38 in the two modes.
)1 must be set. Therefore, the value of C needs to be set in the range of about 383 to about 5.33. Due to the JK symmetry of the cylindrical part 40.41 and the conical part 42, the other high oak 7-1'(U'Mo1 and "M21) that can be propagated (if C: > 3.83) Excitation can be slightly prevented.I) Since l is set equal to one wavelength in the low frequency band, the formula (
4) to the next”: sea urchin.

C: π λ L/ N, H, (10 Therefore, the ratio λJ
7/λ1-1 needs to be set in the range from about 3.83/π to about 5.33/π, that is, from 1.22 to 1.61.

In this way, it is necessary to set the two frequency bands so that the two frequency bands are added together. ), 1. and 1
Moon is approximately 7.5C7M 2.953 inches], No'Ij is approximately 5CNoI+ (1,969 inches), λI, //, 1.
is 15, so the surface circumference e number band is 4 GH7, and 6 and II z are one suitable value. This ratio/, 1. /ノ、1. The number is in the range from 1, 22 to 161 mentioned above.

In the feed horn experiment shown in FIG. 3, for example, the inner diameter of the small diameter cylindrical portion 40 is approximately 5.40
inch), and the inner diameter of the large diameter cylindrical portion 41 is approximately 7°1C.
Set it to Wt (2,8i0 inch). The conical part 42 connecting the two cylindrical parts has a diameter of 3 to the axis of the feed horn.
Give a half-flare angle β (from equation (9)) of 0°. The axial length of the conical portion is approximately 1.5α (0,593 inches)
It is. The length of the cylindrical portions 40 and 41 on both days is approximately 2
．． 5 an (t, 0 inch) and approximately 11.5 cm (4,
58 inches).

The above experimental equipment is 3. g5GHz and 6°17
At 50 Hz, the E-plane and H-plane power patterns shown in FIGS. 4 and 6 were generated.

FIGS. 4 and 6 show the amplitude in decibels along the arc length of a circle with a radius of 27.9 (11 inches) or more whose center coincides with the center position of the antenna aperture.

This same feed horn is 8.95GHH each.
z and 6.175GHz, Figures 5 and 7
The E-plane and H-plane phase patterns shown in the figure were generated.

As is clear from Figures 4 and 6, in any band, the patterns on the E and H planes are almost the same, and the amplitude is at a position 45° off-axis (at the edge of the main reflector). If the current is low enough, a suitable total energy can be reliably captured by the reflector. As is clear from Figs. 5 and 7, up to an axis deviation angle of 45°, E
And the phase pattern curve is relatively flat in the H plane.

In the present invention, the feed horn 11 is embedded in a planar reflector 13, so that the aperture obstruction effect of the VC and Schiffed horn is minimized, and the planar reflector 13 acts as an installation surface for the feed horn. As a result, since the line current at the feeding horn opening is small, current flowing through the plane reflector 13 can be avoided. By using a feed horn as shown in FIG. Since the surface patterns are approximately equal to each other 9, horizontal radiation (i.e., 90° radiation propagated directly from the feedhorn without reflection) will be very low.

Feedhorns other than those mentioned above may be used in the present invention.
For example, a corrugated feedhorn (expanded or pipe-shaped) can also produce a low line current at the feedhorn aperture and equalize the antenna radiation patterns in the E and H planes. However, the feed horn shown in FIG. 3 has a small aperture, so the aperture interference is the least, which is preferable.

10 pieces of raw blood were placed in a 45° dish (subtended angle).
By arranging it so that ψD is 45°), the embedded feed horn 11 can illuminate the entire surface of the main reflector 130 without interference from the inclined plane reflector 13. I can do it.

The ratio between the focal length and the diameter of the upper plate 10 is as follows:
/, D=l/4 tan (ψD/2) αυ Therefore, in the antenna of the present invention, the above ratio needs to be about 0.6039, so it becomes ψD-45°.

In the fully embedded state, position the feed horn 11 or the expanded wave feed horn as follows. That is, the phase center of the feed horn opening end (1) coincides with the focal point F of the parabolic dish, (2) from the surface of the plane reflector 130 in the axial direction F of the parabolic dish.
ff1ll treasure 1- and position them so that they are separated by a length equal to the radius r of the open end of the foot horn.

The radius r of the open end of the feed horn is defined as the distance from the center of the open end of the feed horn to the outermost surface of the feed horn. This second approximate relationship is as shown in Figure 8.
The blood axis, the flat surface of the feed horn opening, and the flat surface of the flat reflector 13 form a right triangle with an angle of 45°.

By embedding the feed horn in the planar reflector 13 to reduce the aperture disturbance effect and suppressing the surface current generated in the planar reflector 13 by the feed horn 11, the center line directional radial line of this reflecting antenna can be reduced. (hereinafter referred to as RPE) is equivalent to, or in some cases superior to, the RPE of an offset reflector. With an offset axis antenna,
Although reflectors generally generate orthogonal polarization interference, the axisymmetric structure of the antenna according to the invention prevents such interference. E-plane and H-plane antenna directivity diagram (radia
Orthogonal polarization interference can be further reduced by using Rufied horns with equal ion patterns.

The antenna of the present invention has a significantly improved RPE and a relatively small wind load factor compared to previous axisymmetric antenna structures. This antenna mounting structure is much cheaper than mounting other types of antenna devices. Figures 8 to 11 show 3. g5
An antenna radiation pattern of a planar parabolic reflector antenna of the present invention at a frequency of GHz is shown. To measure the performance of the antenna, we constructed an antenna that was scaled down by a factor of 7.098. In detail, we performed a simulation of the performance of a full-scale antenna with a parabolic dish with a diameter of about 3 m (10 feet 1 -), and also performed a pattern (8th
-11) to predict the dish diameter of approximately 43.2
Configure an antenna of G+ (1 finch) and set the scaled frequency (
i.e. the product of 7.058 and 395GHz or 7.0
58 and 27.880H2).

Therefore, the feed horn 11 that generates the patterns shown in FIGS.
, was used in combination with a 2Cm antenna.

As a result of measuring the antenna directivity diagram in the E plane and the H plane for the planar parabolic reflection antenna with a reduction ratio of 7.098 according to the present invention, pattern A shown in Fig. 9.10 was obtained. 8.95 of a shielded axisymmetric single-reflection parabolic dish antenna.
The performance of the antenna is shown to be superior compared to RFEB at GHz.

The l1LPE measurement value C of the E plane and H plane in Figs. 8 and 9 is
3 respectively. g for an offset reflector antenna at 5GHz. As is clear from the comparison of the patterns and the radial diagram, the planar parabolic reflection antenna according to the present invention (pattern A) has approximately the same performance as the offset structure (RPE C).

1O and 11 respectively show 3.3 of an antenna according to the invention. The antenna directivity diagram A of the E plane and the H plane with a full angle of 360° at g5GHz is shown. These patterns were also measured using an antenna with a reduction ratio of 7.098. For comparison, 30g5an is shown in Figures 1O and 11.
E and H plane antenna directivity of shielded nest-reflector parabolic dish antenna and offset reflector antenna at z Figure 13.
C is also an indication.

As shown by the patterns in FIGS. 8 to 11, the pattern of the planar parabolic reflector antenna of the present invention is superior to the RPE value B of the axially symmetric single reflector antenna, and the RPE value B of the offset reflector antenna is superior to that of the offset reflector antenna in terms of overall performance. It is almost equivalent to the value C. When the performance of the antenna of the present invention in the 5 GHz frequency band was predicted, the antenna directivity diagram was 3.9.
Similar to or better than 5 GHz antenna pattern.

Another embodiment of the present invention will be described with reference to FIGS. 12 to 14.

In this embodiment, the earthenware 50 having a non-circular paraboloid is used instead of the earthenware 10 having a circular paraboloid shown in FIG. 1.2. When used on the ground, the width of the horizontal plane antenna directivity of the antenna or the width of the antenna's vertical plane antenna directivity becomes even more important. This is because interference along the ground surface (i.e., horizontal plane) between multiple antennas adjacent to each other on the ground is a big problem, but the width of the sailing plane is not so much of a problem. (
14) and 12 using the feed horn shown in Fig. 3.
．． The predicted value of the antenna directivity diagram of the reflection antenna in Figure 13 is:
The antenna directivity factor measurements for the planar parabolic reflector antenna of Figure 1.2 using a circular parabolic reflector of about 3 II l (lO feet) are also superior.

In Figure 14, for example, the focal length is about 1.5? n(
A circular parabolic reflector (shown in dashed line) of diameter approximately 4.5 II+ (15 feet) with f:
Pottery 50 having a non-circular paraboloid can be formed by cutting the paraboloid into approximately 18 #I (6 foot) strips. The focal length to diameter ratio of the reflector is 5 in the horizontal plane.
/15 or 1/3 (0,333), in the vertical plane 5/
6 (0,833), this is fresh blood 10 in Figure 1.2.
This contrasts with a single focal length-to-diameter ratio of 0.6086.

Since the focal length to diameter ratio of the live blood 5tl is different between the horizontal plane and the vertical plane, the gain of the live blood 50 is almost the same as the gain of the live blood 10 in the first embodiment, but the antenna directivity in the horizontal plane is The figure shows that p is narrower than the antenna radiation pattern on the horizontal plane generated by the ball surface 10 having a circular paraboloid surface, and the antenna radiation pattern on the vertical plane is narrower than that in the vertical plane generated on the one plate 10 in the first embodiment. The antenna directional map also becomes wider. In detail, the diameter of a circular paraboloid is approximately 31+I (10 feet)
The ratio of 4.5211 (15 feet) in the horizontal dimension of the non-circular paraboloid is the ratio of the 3 dB width of the horizontal plane of the circular paraboloid to the 3 dB width of the antenna radiation pattern of the horizontal plane of the non-circular paraboloid. Similarly, the diameter of a circular paraboloid is approximately 3? The ratio of l+ (10 feet) to 1.88I (6 feet) in the vertical dimension of the non-circular paraboloid is 3 decibe of the antenna radiation pattern in the vertical plane of the circular paraboloid. 3 dB beam +i+a+ on the vertical plane
is inversely proportional to the ratio of In the reflecting antenna according to the present invention, in order to replace the round surface 10 having a circular paraboloid with one plate 50 having a non-circular paraboloid having the same gain, it is necessary to make the surface areas of the amphibious type substantially equal. Therefore, the horizontal dimension of the non-circular paraboloid surface 50 is approximately 4.5 I
II (15 feet) and the vertical dimension is approximately 1.8 In.
(6 feet) maintains approximately the same gain as a circular parabolic reflector with a diameter of about 32?1 (IO feet).

The mounting support structure for the non-circular parabolic antenna is the same as for the circular parabolic antenna, but its dimensions and shape need to be modified to fit one dish, ie, the non-circular parabolic reflector. In particular, the X-axis dimension of the mounting support structure in FIG. 12 is also longer than the corresponding dimension in FIG. 5 +lr
(15 feet 1-) and the resulting chord angle ψ9
It is necessary to respond to the increase in 'Also, the X-axis dimension of the mounting support structure in Figure 13 is shorter than the corresponding dimension in Figure 2, and is approximately 1.8 m from the Y-axis dimension of the parabolic reflector (approximately 3 mc 10 feet). Is it necessary to be able to reduce it to vl (6 feet)?

Since the mounting support structure for both embodiments of the reflector antenna according to the invention is substantially the same, the reference numbers used in connection with FIG. 1.2 are also used in FIG. 12.18. Further, since the mounting support structure has been explained in the description of the embodiment shown in FIGS. J and 2, this explanation will be omitted in the other embodiment of the present invention shown in FIGS. 12 and 13. Note that the opening 16 of the cylindrical housing 15 in FIG. 12 has a different shape from the opening 16 in FIG. 1. Such a change in the shape of the aperture 16 is due to changing the shape of the parabolic reflector (one dish) from circular to non-circular. The dimensions of the feed horn 11 used in one dish 50 of the non-circular paraboloid in Fig. 3 are the same as those used in one dish of the circular paraboloid of approximately 3111 (10 feet). The first as a surface reflector (1 plate) 50
Although only an oval shape is shown in FIG. 4, a non-circular shape other than that shown in FIG. 14 may be adopted as one dish 50. For example, a parabolic reflector may be oval shaped with a long axis dimension of about 4.5 Tn (15 feet) and a short axis dimension of about 1.8 Tn (6 feet). Although the feed horn 11 of FIG. 3 is used in the planar parabolic reflector antenna of FIGS. 12 and 13 according to the present invention, other feed horns 11 may be used. The expanded waveform feed horn is that mm1. Since the one plate 50 is a non-circular fit, it is also desirable to improve the gain by employing a feed horn provided with a non-circular opening (for example, an elliptical or rectangular opening).

(Effects of the Invention) As is clear from the above explanation, the planar parabolic reflection antenna in which the feed horn is embedded in the planar reflector minimizes the performance degradation of the axially symmetric antenna due to the aperture disturbance effect of the feed horn. be able to. By using a feedhorn with reduced total current, the recessed feedhorn does not generate large ground currents in the planar reflector. By using the feed horn shown in FIG. 3, the aperture for the feed horn in the planar reflector is small, thereby further preventing interference with the feed horn. Further, according to the above-mentioned shape of the antenna, the contribution of the feed horn to the horizontal plane radiation of the antenna becomes radiation deviated by 90° from the axis of the feeding horn, and this contribution is extremely low. Therefore, an axially symmetrical antenna with an excellent radiation pattern and low wind load factor can be realized at low cost.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embedded type feed horn reflection antenna according to the present invention, Fig. 2 is a sectional view taken along line 2-2 in Fig. 1, and Fig. 3 is an enlarged sectional view of the feed horn. 3. Figure 4 uses the feed horn shown in Figure 3. Figure 5 is a diagram showing the power pattern of radiation in the E and 8 planes measured along the long axis at a frequency of 5 GHz. Measure about the axis iE
A diagram showing the phase pattern of the radiation in the plane and the 8 planes, Figure 6 is a diagram showing the phase pattern of the radiation in the plane and the 8 planes.
, 17] Diagram showing the power pattern of radiation in the iE plane and the 8 plane measured on the long axis at a frequency of GHz, FIG. 7 is shown in FIG.
Figure 8 is a diagram showing the phase pattern of radiation in the E plane and the 8 plane measured along the long axis at a frequency of 6.175 GHz. The antenna directivity diagram of the approximate eight planes of the reflection antenna of the present invention predicted at the frequency of '95 G B' z is as follows:
A diagram comparing the H-plane antenna directivity radial diagram of an offset antenna and a conventional axisymmetric antenna with almost similar gains measured at a frequency of 3.95 GI (z). The antenna directivity diagram of the approximate E plane of the reflection antenna of the present invention predicted at the frequency of 3,g5G
A diagram comparing the E-plane antenna directivity radial diagram of an offset antenna with almost similar gain and a conventional axisymmetric antenna measured at a frequency of Hz, Figure 1O is predicted at a frequency of 3.95 GH2. The 360° full-angle E-plane antenna directivity diagram of the reflector antenna of the present invention was measured at a frequency of 3.950) lz. A diagram shown in comparison with the directional radial diagram, Fig. 11 395GI (E-plane antenna directivity diagram for all angles of 360° of the reflection antenna of the present invention predicted at the frequency of z,
H
12 is a front view showing another example of the reflection antenna of the present invention; FIG. 13 is a sectional view taken along line 13-13 in FIG. 12; Figure 14 is the 12th. It is a perspective view of the reflection antenna shown in the IS diagram.Additional explanation 10...Circular parabolic reflector dish, 11...Feed pawn, 13.One plane reflector, F. Focal point. '%ll Petitioner Andrew Corporation Legal Person Patent Attorney On 1) Hiroshi Senkon's Ori Puoiro 7za is sealed with Todai Ura glaze (Φ赳 is contrasted with Akichū painting + 1.l! Kouchi mark) 1 inch to Yuzu I ◆ 10th horned tiger e s: t'4'i ru 44 M + "3/1-f jl・ Seal with medium and small G @ Muto angle 17th row No. (Digi Hel) Sprinkle 1 too (9' Jibel)

Claims (1)

[Claims] 1. A dead plate reflector with a focal point 1" and a perforated plate reflector 2.
) ÷ focus 1゛2! An aperture center is placed near f, and a foot horn is placed along the beam path for receiving, receiving, and transmitting power, and EruJ: Sea urchin, equipped with a flat reflector placed Mt in an inclined state along the axis of the dish reflector, 1) 1
1. In order to reduce the aperture obstruction effect caused by the feed horn, the feed horn is embedded in the h1] plane m+ reflector, and the same plane refractor is inserted into the dish reflector.
7311, so that the feed horn has a small field at the foot horn aperture in a predetermined frequency band, and the antenna directional radiation diagram of the antenna in a predetermined frequency band is a planar reflector. A reflective antenna with a built-in feed horn, characterized in that the antenna is substantially not exposed to the ground plane formed by the antenna. 2. The recessed foot-horned reflector according to claim 1, wherein the surface of the dish reflector is a circular elbow paraboloid t+q, and the focal length to diameter ratio is about 0.6. antenna. 3. The embedded device according to claim 1, wherein the surface of the W1 reflector is a non-circular parabolic bloodstain, and the value of the focal length to diameter ratio on the vertical plane is larger than the value on the horizontal plane. Reflector antenna with built-in feed horn. 4) The phase center of the feedhorn aperture is located at a distance from the surface of the planar reflector by a length approximately equal to the radius of the aperture, as measured along the axis of the dish reflector. A reflector antenna characterized in that it has a built-in foot horn as described in claim 1. 5. The feed horn operates over two or more frequency bands, and the feed horn has an inner diameter approximately equal to one wavelength of the intermediate frequency in the low frequency band, and the feed horn has an inner diameter approximately equal to one wavelength of the intermediate frequency in the low frequency band. E side and H
Add 6# + the circle string shape '1] part which is K so as to generate a pattern that is approximately /X equal to /
Pj, "ffl"nlsminco f)i Me, ノI
Around hl t iil++ Zhou? ) hM! 4 j? In the area, the setting is made to eliminate small differences at the edge of Xj: 1-in-opening 1'', thereby making the 'rJL flow at the edge of the horn opening zero, and setting 1 in the high frequency 0 band of 111J. The embedded feedhorn reflector antenna described in item 1 of the scope of the patent αJ, which is characterized in that it generates a substantially erratic pattern on the 111 and 11 planes. 6.l! jl Encyclopedia No. 19 The 5 minute small diameter end for the waveguide is
'J' of the microwave signal propagated through the same small diameter end
M, lJ, I that is small enough to prevent the propagation of n mode
The embedded feedhorn reflection antenna according to claim 5, characterized in that the diameter is greater than 4+ffi. 7 Connect a straight waveguide section with a uniform inner diameter to the large diameter end of the conical waveguide section, and In-phase i' of one microwave word in high frequency band, F4. 6. The embedded foot-hole reflection antenna according to claim 5, wherein the antenna is set to generate the T oil 1 mode and the T oil 1 mode. 8 1jiJ circle Zlf, shape 49 r and large diameter width i of the pipe part No. 11:, 1? Y: 't, n: Large enough to allow the transmission 171 layer of the '1゛Δ111 mode of the microphone 1J Kitawara in the J high frequency band, and the 'J'E, 2 mode of the same microwave signal. 5. A reflection antenna with an embedded feed horn according to claim 5, characterized in that the antenna has a small projection so as to prevent the propagation of the feed horn. 9 The inner diameter of the large diameter width i of the circular CIL waveguide portion +3
Generate a value C-πI)1/n·IJ in the range of about 383 to about 5331 in the high frequency band iJ, [)
) 1) A wide-force elevating oak that can propagate in a high frequency band by using the large-diameter end of the conical waveguide section.
9. The reflection antenna with a feed horn according to claim 5. 10, 'iiJ The ratio of the wavelength of the intermediate frequency in the low frequency band to the wavelength of the 1uj frequency in the high frequency band is within the range of about 1.22 to about 161 cm. An embedded reflective antenna according to claim 5. o, 1iii) The circular cylindrical wave tube bar 1-min has a uniform inclination angle β (degrees) that is fixed by the following formula, and 11 is the wavelength at the intermediate frequency of the high frequency band. ,
No, 1. 6. The embedded foothorn reflective antenna according to claim 5, wherein the wavelength is at an intermediate frequency in a low frequency band. +2 +iii The embedded feed-pond reflecting antenna according to claim 4, wherein the feed horn is a recessed feed horn. 13 the dish reflector has a focal length to diameter ratio of about 0.6;
? 145° parabolic plate, and a feed horn can be embedded in the plane reflector while maintaining irradiation to the entire parabolic plate. Recessed feedhorn reflector antenna. 14 a dish reflector having a focal point, a plane reflector tilted along the axis of the dish reflector so as to change the direction of the radiation wave toward/from the dish reflector; The aperture center is arranged near the focal point and the dish reflection 2F is provided along the beam path.
1) Measured along the axis of the dish reflector marked 1j, rotate Luυ around the surface of the planar reflector by a length approximately equal to the radius of the opening 1', and then place it on the feed horn marked O1j. Fee 1 to minimize the aperture obstruction effect caused by
- An embedded-type 7-horn reflector antenna characterized by a pawn embedded in a flat reflector. +5. ii. The reflector antenna with an embedded feed horn according to claim 14, wherein the surface of the reflector is circular parabolic and has a focal length to diameter ratio of about 0.6. . 16. Claims characterized in that the surface of the dish reflector is a non-circular paraboloid, and the value of the focal length to diameter ratio in the vertical part is larger than that in the horizontal plane! 21J paragraph 14. 17 The feedhorn has a annihilation electric field at the edge of the aperture, and either the edge current of the aperture of the feedhorn or the planar reflection that lowers the antenna directional radiation diagram of the antinode is insufficient to cause a ground plane current of Embedded feed horn (reflection antenna. At the same time, the feed horn is activated.
A conical waveguide whose large diameter end has an inner diameter approximately equal to the [wavelength] of the intermediate frequency in the low frequency band, so as to generate approximately equal patterns in the E plane and HrMJ in the low frequency band. The internal slope of the conical JI'14 waveguide positive part is set so as to eliminate the electric field at the high frequency range Nioitehorn opening, so that the E and 11 planes are approximately equal to υ in the high frequency band. 15. The embedded feedhorn reflector antenna according to claim 14, wherein the antenna generates an equal pattern. +9 r: The small diameter end of the conical waveguide section is the 'I'M of the microwave signal propagated through the entire small diameter end.
,,. An embedded feed reflector antenna according to claim 18, characterized in that it has a diameter small enough to block the propagation of modes. Waveguide details 1 (minutes 1ii
J is connected to the large diameter ghi of the conical waveguide section, and the length of this straight waveguide section is determined as the in-phase of the micro-transmission example in the high frequency band at the open end of the straight waveguide section. 1”h
19. The recessed feedhorn reflector antenna according to claim 18, wherein the antenna is set to generate the "11" and "TΔ11" modes. 21 The diameter of the large diameter end of the conical waveguide section is made large enough to allow the propagation of the 'J' wave of the microwave false signal in the high frequency band, and Claim 1 is characterized in that the value is set small so that propagation of the l'E12 mode can be prevented.
The embedded feedhorn reflector antenna according to item 8. 22 The inner diameter of the large diameter end of the conical waveguide section has a value within the range of about 383 to about 5.88 t in the high frequency band. The person in the waveguide part? Follow the edge of A to reach the upper 1 inverse band 2
Excitation that can be propagated 1! % order 7-to ゛takegai'
Claim 1 characterized in that it is J1,000-dore.
8. Embedded feedhorn reflection antenna of Mound IC d&. 2:3 The ratio of the wavelength of the intermediate frequency in the low frequency band to the wavelength of the intermediate frequency in the high frequency band is about 12
19. A recessed reflector antenna according to claim 18, characterized in that the antenna is within the range of 2 to about 1.6]t. 24 The conical waveguide section has a uniform tilt angle β (degrees) defined by the following equation, where λ11 is the wavelength at the intermediate frequency of the high frequency band and λ
Embedded feedhorn reflection antenna according to claim 18, characterized in that L is a wavelength at an intermediate frequency in a low frequency band. So... himself? J-9 Mukoyu Shinasu - Tsumejyu no Yato■ Whistle 17rliV described reflection antenna with an embedded feed horn. 261iJ plate reflector or focus icL! It is a parabolic dish with a diameter ratio of about 45° to the dish IIU of about 06, and is characterized by being able to embed a flat reflection horn while maintaining irradiation to the entire parabolic surface. A reflection antenna with an embedded feed horn according to claim f2J14. Claim 16 wherein the reflector has a focal length-to-diameter ratio of about 0.833 and about 0.333 in vertical and horizontal planes. Embedded feedhorn reflector antenna described in .