TW201407880A - Offset Cassegrain dichroic antenna system for extra-broadband multi-channel - Google Patents

Abstract

An offset Cassegrain dichroic antenna system for extra-broadband multi-channel is provided, wherein the antenna system is used for transmitting and receiving signals from satellites. The antenna system can perform uplink and downlink of signals between ground equipment and antennas of satellites. The antenna system of the invention uses the offset Cassegrain dichroic antenna system, wherein a dichroic sub-dish is arranged at one side of an axis by means of offset, wherein the dichroic sub-dish can reflect low frequency signals and allow high frequency signal passing through. With the selection of low frequency band and high frequency band, the two frequency bands are both extra-broadband that is normally greater 10%, and its high frequency band could achieve 35% bandwidth even. In addition, the metal sheet structure of the dichroic sub-dish in the invention is divided into several regions. Each region contains its own metal sheet structure arrangement. The metal sheet structures within each region are uniformly distributed and periodically arranged. The metal sheet structures within different regions are fine-tuned, wherein the fine-tuning adjustment of the metal sheet structures is mainly regulated according to angles of incident waves. The arrangement can allow the dichroic sub-dish of the invention to receive incident radio from different angles, and excellent low frequency reflection rate and high frequency transmittance rate to achieve extra-broadband.

Description

Extremely wide frequency multi-channel partial displacement Cassegrain crossover antenna system

This creation is about antenna systems, especially an extreme wideband multi-channel offset Cassegrain dichroic antenna system.

The related patents and materials of the present invention are as follows: US 6,774,861 (Reference 1), US 6,512,485 B2 (Reference 2), V. Agrawal, W. Imbriale "Design of a dichroic cassegrain subreflector" IEEE Trans. on Antenna & Propagation, 1979 Vol.27, Issue4, Page 466~473 (Ref. 3), US3231892 (Ref. 4).

The traditional cross-section mirror (Dichroic Sub-dish) is set to the antenna of either the offset set (Casset) or the Cassegrain reflector without the offset. The crossover (dichroic) The design is to use uniform and period dichroic elements for the arrangement of the metal elements on the mirror surface, that is, all the components on the mirror surface are of the same specification and are uniform with each other. Periodic arrangement.

Refer to the second document to explain the frequency selective surface (FSS) or generally in the application of the antenna. Dichoroic can reflect and transmit the frequency band of the incident wave separately. The mechanism of the shot) mirror is used in the Sub-dish, or Sub-reflection, to isolate the two different frequency bands. The signal of one of the frequency bands penetrates the frequency division mirror and is concentrated to a prime focus point. The signal from the other band is reflected and concentrated to an Image focus point. This traditional multi-band antenna design has been disclosed in references three and four. However, FSS or crossover technology is generally only used in mixed or large-capacity military or dedicated satellite communications, as well as some special applications, and almost no receiving antennas for low-cost commercial satellite communication ground.

In traditional FSS or dichroic techniques, the high frequency feed horn is placed at the image focus point and the low frequency feed horn is placed at the prime focus point. Both the high frequency band and the low frequency band are narrow bandwidths, and the bandwidth used for communication is usually 5% of the carrier frequency. In reference two, the high frequency band has two separate frequency bands, one is 20 GHz, the other is 30 GHz, and the low frequency band is at 12.4 GHz, which is about 5% of bandwidth in each frequency band.

In the traditional antenna design, the carrier frequency ratio of the high frequency band and the low frequency band is mostly 1.5 or more. In traditional antenna designs, multi-band uses a Dichroic Sub-dish design, as seen in reference three. The carrier ratio of the high and low frequency bands is very large, for example, 12 GHz and 6 GHz (the ratio of the general high frequency band to the low frequency band is about 2) and both use no offset bits. (Offset) normal Cassegrain reflection. The recent application of satellite television (DBS) has only begun to use Offset Cassegrain Reflector, as disclosed in references one and two. The ratio of the high frequency band to the low frequency band is between 1.5 and 2, for example, 30 GHz/12 GHz and 20 GHz/12 GHz, but the offset dichroic Sub-dish is designed due to the offset (offset). The relationship between the incidence of radio waves incident on the dichroic sub-dish is not perpendicular to the incident and the angle varies greatly, which makes the design more difficult, and thus the conventional Dichroic design cannot reach the wide frequency ( Wide-bandwidth).

Current applications, especially in the next generation of satellite TV applications (DBS), traditional TV broadcasting can not meet the rapid development of modern multimedia such as HDTV, 3D HDTV, IPTV (Voice on demand, VOD), two-way communication Internet, etc. On the demand. The current concept of satellite communication requires that a satellite must be able to use two Ku bands and one Ka band simultaneously as the frequency band of the downlink signal, and also use one Ku band and one Ka band as the frequency band for uploading signals to meet the current large number. The need for communication. Therefore, the bandwidth used must be large enough, and according to the current design of the next generation satellite television system, the bandwidth requirement for the high frequency band is much higher than the bandwidth requirement of the low frequency band.

The traditional design of the cross-range (dichroic) Cassegrain antenna (as described in references 1 and 2) places the high frequency feed horn At the image focus point; that is, the frequency division sub-mirror reflects the electric wave. The principle of its ability to reflect electric waves is achieved by the use of a metal sheet structure on a dichroic to induce electromagnetic resonance at this high frequency band. In general, this design has a limited bandwidth unless complex multi-layer dichroic surfaces are used. However, the design of such a multilayer resonant metal piece cannot be made to function as a broadband because the incident angle of the electric wave changes too much. Therefore, the design of the traditional crossover antenna has failed to meet the requirements of the next generation satellite TV.

Therefore, the inventor of this creation needs to conceive a new technology to improve its problems.

Therefore, the purpose of this creation is to solve the above-mentioned problems in the prior art. In this creation, a very wide-band multi-channel partial displacement Cassegrain crossover antenna system is proposed, which aims to make the selection through the low frequency band and the high frequency band. Both frequency bands are extra-broadband, which are generally greater than 10% or even 35% of the bandwidth, especially the high frequency band is wider than the low frequency band. Therefore, for the next generation of satellite television (DBS), it is required that the low frequency band must satisfy the Down-link frequency band of 10.7 GHz to 12.75 GHz, and the high frequency band has a 17 GHz uplink (up-link), 18 to 20 GHz. Down-link and 24 GHz up-link, a total of 17 to 24 GHz is almost 35% of the bandwidth requirement. And the design of this case has reached To the above bandwidth requirements. The proportion of high frequency band and low frequency band in this case is very small. For example, 17GHz/12.75GHz has a ratio of only 1.3. In this case, an offset sub-dish is used to reduce the blockage caused by the sub-mirror. It will make the design of traditional crossover (dichroic) and Cassegrain Reflector have a new concept and breakthrough. First, because the bandwidth requirement of the high frequency band is much higher than the low frequency band, the metal piece on the frequency division sub-mirror surface is designed to perform electromagnetic resonance on the incident wave of the low frequency band, and the electric wave of the low frequency band is reflected and concentrated to the image focus ( Image focus point). The high-frequency electric wave penetrates the frequency-divided sub-mirror and is concentrated to the prime focus point. In addition, in this case, the metal piece structure of the frequency division sub-mirror surface is not a conventional uniform distribution and periodic arrangement design, but a structural design in which the metal piece is finely adjusted according to the incident angle of the electric wave is adopted. Due to the design of the single layer dichroic surface, the sensitivity to the incident angle of the radio wave is not very large. The metal sheet structure on the sub-mirror surface can be divided into several regions, and each region has its own metal sheet. The arrangement of the structures, the metal sheet structures in each area are uniformly distributed and periodically arranged. The metal sheet structure in different areas has fine adjustments. The configuration of the metal sheet structure is mainly based on the angle of the incident wave. This configuration can make the frequency dividing sub-mirror in this case can receive incident electric waves from different angles, and both have excellent low-frequency reflectivity and high-frequency transmittance and achieve extremely wide frequency function.

In order to achieve the above objectives, the present invention proposes an extremely wide frequency multi-channel partial displacement Cassegrain crossover antenna system, wherein the antenna system It is used to transmit and receive signals from satellites. The antenna system can upload and transmit signals between the ground device and the antenna on the satellite. The antenna system comprises: a parabolic mirror; the parabolic mirror has a corresponding one. a focus axis, the parabolic mirror being disposed on one side of the axis in an offset manner, the parabolic mirror having a focus point on the focus axis; a sub-dish The frequency division sub-mirror is mainly a lens arranged along a double curved surface, the frequency dividing sub-lens has a prime focus point, the main focus coincides with the focus of the parabolic mirror, and still includes an image An image focus point on the focus axis of the hyperboloid mirror. In the present invention, the frequency dividing sub-reflecting lens is disposed on one side of the axis in an offset manner, and the axis of the mirror surface is The axis of the mirror surface of the parabolic mirror may not be repeated; wherein the frequency-divided sub-lens may reflect the low-frequency signal and pass the high-frequency signal; at least one primary feed horn is a pass The signal receiving point of the front corner or other design, the signal receiving point of the front end overlaps with the main focus, for receiving the high frequency electric wave penetrating the frequency dividing sub mirror or transmitting the high frequency electric wave toward the frequency dividing sub mirror; at least one The image feed horn is a conventional angle or other designed transceiver mechanism, and the signal receiving point of the front end overlaps with the image focus for receiving low frequency electric waves reflected from the frequency dividing sub mirror or directing low frequency electric waves toward The frequency division sub-mirror emits; wherein the frequency division sub-mirror reflects the low frequency signal, and the low frequency signal is received by the image radio wave transceiver mechanism; and the high frequency signal penetrates the frequency division sub-mirror, and the main wave transmits and receives Received by the agency.

The features of the present invention and its advantages can be further understood from the description below, and please refer to the attached drawings when reading.

In view of the structural composition of the case, and the functions and advantages that can be produced, in conjunction with the drawings, a preferred embodiment of the present invention is described in detail below.

Referring to Figure 1, there is shown a configuration diagram of the elements of the present invention. The present invention comprises the following elements: an antenna system 10 for transmitting and receiving signals from satellites that can be used for uploading and transmitting signals between terrestrial devices and antennas on satellites. The antenna system mainly comprises: a paraboloidal reflector 12; the parabolic mirror has a corresponding focal axis 20, and the focus axis has a pair of focal points 22 that should be parabolized, wherein the antenna A focal length 24, which is the distance between the focus and the apex of the parabolic mirror 12, has a radiation aperture 26 that is a cross-section that accepts external radiation. In the present invention, the parabolic mirror 12 is disposed on one side of the axis in an offset manner.

A dichroic sub-dish 14 is mainly a lens that is arranged in a hyperbolidal configuration, and may be a flat surface when implemented. The frequency dividing sub-mirror 14 has a spoke A cross section 28 and a prime focus point 30a, the main focus 30a coincides with the focus 22 of the parabolic mirror 12, and still includes an image focus point 30b, which is the focus axis of the hyperboloid 14. On the line, the focus axis may or may not coincide with the focus axis 20 of the mirror surface, but at a distance from the main focus 30a. In the present invention, the frequency dividing sub-mirror 14 is disposed on one side of the axis in an offset position, and the axis of the mirror surface may or may not coincide with the axis of the mirror surface of the parabolic mirror 12.

The frequency dividing sub-mirror 14 can reflect the low frequency signal and pass the high frequency signal. The low frequency band in this case refers to the frequency from 9 GHz to 15 GHz, while the high frequency band refers to the frequency from 17 GHz to 30 GHz.

A primary feed horn 16 is a conventional angle or other designed transceiver mechanism, and a signal receiving point at the front end thereof overlaps with the main focus 30a for receiving high frequency waves penetrating the frequency dividing sub mirror 14. Or, the high frequency electric wave is emitted toward the frequency dividing sub-mirror 14.

An image feed horn 18 is a conventional angle or other designed transceiver mechanism, and a signal receiving point at a front end thereof overlaps the image focus 30b for receiving low frequency waves reflected from the frequency dividing sub-mirror 14 or The low frequency electric wave is emitted toward the frequency dividing sub-mirror 14.

The main radio wave transmitting and receiving mechanism 16 and the image radio wave transmitting and receiving mechanism 18 in the present case all have the appearance of a conventional horn or other design shape.

The material selection of the frequency-division hyperboloid mirror can be referred to the structure disclosed in paragraphs 4 and 5 of the description of the preferred embodiment of U.S. Patent No. 6,774,861 B2. The following is a general description: refer to Figure 2A, Figure 2B and Figure 2C, where the frequency dividing sub-mirror 14 comprises the upper and lower layers of Kevla or Mylar or other crossover mirror surface material 33, and a Kevla ^® The honeycomb or other physical material structure is distinguished. The grating frequency bipolar dividing a frequency selective sub-reflecting surface 32 of mirror 14 comprises a copper etch on Kevla ^® or Mylar or other similar surface texture or other surface shape of the structure 32 of the selection. By applying this type, the signals of the high frequency band and the low frequency band can be respectively penetrated and reflected, so that the signals of the two frequency bands are separated, and the reflected low frequency signals are directed to the image wave transmitting and receiving mechanism 18. . And the passed high frequency signal is directed to the main wave transmitting and receiving mechanism 16.

Referring to FIG. 3, there is shown a cross-sectional view showing the positional relationship between the frequency dividing sub-mirror 14 and the main radio wave transmitting and receiving unit 16 and the image radio wave transmitting and receiving unit 18 in the present creation. An incident wave is incident on the frequency dividing sub-mirror 14 at an angle A1. The left side of the figure shows the arrangement of the metal piece components of the mirror of the frequency dividing sub-mirror 14 , and the right side shows the return loss measured under different frequencies. In the figure, six horizontally polarized electromagnetic waves are tested, wherein the six electromagnetic waves are incident at an angle perpendicular to the secondary mirror 14, which has different crossing angles with respect to the arrangement angle of the metal sheets, and these intersecting angles For the 15°, 30°, 45°, 60°, 75° and 90°, please refer to the metal sheet structure on the left side of Figure 3. In Figure 3, the measured return loss is measured at different frequencies when the incident angle A1 is 90 degrees. It shows that the feedback loss is quite low at frequencies from 9 GHz to 15 GHz, so most of the incident waves in this band can be reflected from the frequency dividing sub-mirror 14 without greatly Loss. The relative feedback loss is relatively high when the frequency is in the range of 17 GHz to 30 GHz, so most of the incident waves in this frequency band will penetrate the frequency dividing sub-mirror 14 without reflection. Therefore, from the above relationship, we can understand that the system of the present invention has good reflectivity with respect to the frequency dividing sub-mirror 14 at a frequency of 9 GHz to 15 GHz (low frequency), so the signal can be reflected to the main wave transmitting and receiving mechanism 16, and Received by the main radio wave transceiver unit 16. In addition, the system of the present invention has good penetration with respect to the frequency dividing sub-mirror 14 at a frequency of 17 GHz to 30 GHz (high frequency), so the signal can penetrate the frequency dividing sub-mirror 14 and serve as the image transmitting and receiving mechanism. 18 received. In the figure, six horizontally polarized electromagnetic waves are tested, which have different crossing angles with respect to the arrangement angle of the metal sheets, and the crossing angles are 15°, 30°, 45°, 60°, 75°, and 90, respectively. °. From the feedback loss on the right side of the figure, it can be seen that the effect does not change much at different angles.

The low frequency is 5 GHz to 7 GHz and the high frequency is 9 GHz to 12 GHz with respect to the above-described conventional techniques, and 9 GHz to 15 GHz (low frequency) and 17 GHz to 30 GHz (high frequency) are used in the present case. It can be seen that the bandwidth in this case is far wider than the bandwidth used by the prior art. In this case, a relatively high frequency portion is used, so the bandwidth can be increased to 35% of the carrier, which is much better than 5% of the prior art. The technique of this method can widen the bandwidth of communication, so the amount of communication is also increased. Moreover, it can be seen from the above that the so-called low frequency in the present case is actually a high frequency with respect to the conventional technique, and the so-called high frequency in the present case does not actually use this frequency band in the prior art. Therefore, there has been a great breakthrough in technology in this case.

Please refer to FIG. 4, which shows that the incident electromagnetic wave is incident on the frequency dividing sub-mirror 14 in the direction of horizontal polarization, wherein the incident angles are 15°, 30°, 45°, 60°, 75°, and 90°, respectively (please refer to the figure). The structural configuration diagram on the left). It shows that the value of the feedback loss becomes smaller with respect to different incident angles, especially when it is high frequency. Therefore, we need to consider this feature in designing the frequency dividing sub-mirror 14. The configuration and arrangement of the sheet metal components must be appropriately designed such that at different angles, the curve of the feedback loss can tend to a feedback loss curve with an ideal incident angle of 90°.

Referring to FIG. 5, it is shown that the incident electromagnetic wave is incident on the sub-mirror 14 in the direction of vertical polarization, wherein the incident angles are 15°, 30°, 45°, 60°, 75°, and 90°, respectively. It shows that the feedback loss value becomes smaller with respect to different incident angles, which is a characteristic that would be disadvantageous for reflection at low frequencies. Therefore, we need to consider this feature in designing the frequency dividing sub-mirror 14. The configuration and arrangement of the sheet metal components must be appropriately designed such that at different angles, the curve of the feedback loss can tend to a feedback loss curve with an ideal incident angle of 90°.

Please refer to FIG. 6, which shows the angle between the radio waves transmitted by the radio wave transmitting and receiving mechanism to the frequency dividing sub-mirror 14, which is shown between the two ends of the frequency dividing sub-mirror 16 (θ 1 and θ 2 ). ) shows a big change. Similarly, in the figure, the angle between the transmitted electric wave of the image radio wave transmitting and receiving mechanism 18 and the both ends of the frequency dividing sub-mirror 14 (θ 3 and θ 4) also undergoes a large change, so the frequency dividing sub-mirror The physical response between the material and the transmitted wave is also very different. Therefore, according to Figure 3, The experimental results of FIG. 4 and FIG. 5 are as shown in FIG. 2D and FIG. 2E. In this case, the metal sheet structure on the frequency dividing sub-mirror 14 is changed according to different angles of the incident wave. Preferably, the metal sheet structure on the frequency dividing sub-mirror 14 can be divided into a plurality of regions, each of which has an arrangement of respective metal sheet structures, and the metal sheet structures in each region are uniformly distributed and periodically arranged. The different metal sheet structures in different regions have been finely adjusted. The configuration of the metal sheet structure is mainly based on the angle of the incident wave. According to Figure 4 and Figure 5, the response of the metal sheet structure to the incident angle does not change within plus or minus thirty degrees, so the distinction of the area is not necessarily too fine; every 20 to 30 degrees can be separated as a region. .

As shown in FIG. 7, when there are multiple satellite signal transmission paths L1, L2, and L3, respectively, the signal receiving system in the present case has the parabolic mirror 12 and the frequency dividing sub-mirror 14 arranged in the same manner as the above-mentioned FIG. In the above, only a plurality of radio wave transceivers are used in this example to receive signals from different satellites.

The advantage of this case is that after the selection of the above low frequency band and high frequency band, the two frequency bands can be made of extra-broadband, generally more than 10% or even 35% of the bandwidth, especially in the high frequency band. The lower frequency band is more broadband. Therefore, for the next generation of satellite television (DBS), it is required that the low frequency band must satisfy the Down-link frequency band of 10.7 GHz to 12.75 GHz, and the high frequency band has a 17 GHz uplink (up-link), 18 to 20 GHz. Down-link and 24GHz upload-up, in total 17~24GHz is almost 35% bandwidth requirement. The design of this case has reached the above bandwidth requirements. In this case, the ratio of the high frequency band to the low frequency band is very small. For example, 17GHz/12.75GHz has a ratio of only 1.3. In this case, an offset sub-dish is used to reduce the radio wave blockage caused by the frequency division sub-mirror. It will make a new concept and breakthrough in the design of traditional crossover and Cassegrain mirrors. In addition, in this case, the metal piece structure of the frequency dividing sub-mirror is divided into a plurality of regions, and each region has an arrangement of respective metal sheet structures, and the metal sheet structures in each region are uniformly distributed and periodically arranged. Different regions have different metal sheet structures. The configuration of the metal sheet structure is mainly based on the angle of the incident wave. This configuration allows the frequency dividing sub-mirror in the present case to receive incident electric waves from different angles, and both have excellent low-frequency reflectance and high-frequency transmittance and reach an extremely wide bandwidth.

In summary, the humanized design of this case is quite in line with actual needs. The specific improvement of the existing defects is obviously a breakthrough improvement advantage compared with the prior art, and it has an improvement in efficacy and is not easy to achieve. The case has not been disclosed or disclosed in domestic and foreign literature and market, and has complied with the provisions of the Patent Law.

The detailed description above is a detailed description of one of the possible embodiments of the present invention, and the embodiment is not intended to limit the scope of the patents, and the equivalent implementations or modifications that are not included in the spirit of the present invention should be included in The patent scope of this case.

10‧‧‧Antenna system

12‧‧‧Parabolic mirror

14‧‧‧Dividing sub-mirror

16‧‧‧Main radio wave transceiver

18‧‧‧Image radio wave transceiver

20‧‧‧focus axis

22‧‧‧ Focus

24‧‧‧ Focus length

26,28‧‧‧radiation profile

30a‧‧‧ main focus

30b‧‧‧Image focus

32‧‧‧ frequency selection surface

33‧‧‧Front mirror surface material

Figure 1 is a schematic view of the first embodiment of the present invention.

FIG. 2A, FIG. 2B and FIG. 2C are schematic diagrams showing the structure of a frequency division sub-mirror of the prior art.

Figure 2D is a front view of the surface metal sheet structure of the frequency dividing sub-mirror of the present invention.

Figure 2E is a perspective view of the surface metal sheet structure of the frequency dividing sub-mirror of the present invention.

Figure 3 is the feedback loss data of the six horizontally polarized electromagnetic waves for the frequency division sub-mirror, wherein the six electromagnetic waves are incident at an angle perpendicular to the sub-mirror.

Figure 4 shows that the electromagnetic wave is incident on the frequency dividing sub-mirror in the direction of horizontal polarization, and its loss data is fed back with respect to different incident angles.

Figure 5 shows that the incident electromagnetic wave is incident on the frequency dividing sub-mirror in the direction of vertical polarization, and its loss data is fed back with respect to different incident angles.

Fig. 6 is a view showing the angle between the electric wave pre-divided sub-mirrors emitted by the radio wave transmitting and receiving mechanism.

Figure 7 is a schematic view of the second embodiment of the present invention.

10‧‧‧Antenna system

12‧‧‧Parabolic mirror

14‧‧‧Dichroic sub-dish

16‧‧‧Main radio wave transceiver

18‧‧‧Image radio wave transceiver

20‧‧‧focus axis

22‧‧‧ Focus

24‧‧‧ Focus length

26,28‧‧‧radiation profile

30a‧‧‧Prime focus point

30b‧‧‧Image focus point

Claims (7)

An extremely wide frequency multi-channel partial displacement Cassegrain crossover antenna system, wherein the antenna system is used for transmitting and receiving signals from a satellite, and the antenna system can perform signal uploading and downlink transmission between a ground device and an antenna on the satellite, the antenna The system comprises: a parabolic mirror; the parabolic mirror has a corresponding focus axis, the parabolic mirror is arranged on one side of the axis in an offset manner; a crossover mirror (dichroic sub-dish) The frequency dividing sub mirror is mainly a lens with a double curved surface, the frequency dividing sub mirror has a prime focus point, and the main focus coincides with the focus of the parabolic mirror, and still includes a An image focus point, on the focus axis of the hyperboloid, the focus axis of the hyperboloid may coincide or be inconsistent with the focus axis of the parabolic mirror, the offset sub-mirror is offset Arranged on one side of the axis, and the axis of the mirror surface may coincide or not coincide with the axis of the mirror surface of the parabolic mirror; wherein the frequency dividing sub mirror reflects the low frequency signal, and the height is high The signal passes; at least one primary feed horn is a conventional angle or other designed transceiver mechanism, and the signal receiving point of the front end overlaps with the main focus for receiving the high frequency penetrating the frequency dividing sub mirror Radio waves or transmitting high frequency electric waves toward the secondary mirror; The at least one image feed horn is a conventional angle or other designed transceiver mechanism, and the signal receiving point of the front end overlaps the image focus for receiving low frequency waves reflected from the frequency dividing sub mirror or low frequency The electric wave is emitted toward the sub-mirror; wherein the frequency dividing sub-mirror reflects the low-frequency signal, and the low-frequency signal is received by the image radio wave transmitting and receiving mechanism; and the high-frequency signal penetrates the frequency dividing sub-mirror, and the main radio wave Received by the transceiver. For example, the extremely wide-band multi-channel partial-displacement Cassegrain crossover antenna system described in claim 1 wherein the low frequency band refers to a frequency from 9 GHz to 15 GHz, and the high frequency band refers to a frequency from 17 GHz to 30 GHz. The ultra-wideband multi-channel partial-displacement Cassegrain crossover antenna system as described in claim 1, wherein the main radio wave transceiver mechanism and the image radio wave transceiver mechanism have a conventional horn shape or other designed appearance. For example, the extremely wide-band multi-channel partial-displacement Cassegrain crossover antenna system described in claim 1 is characterized in that the metal piece structure is divided into a plurality of regions, and each region has an arrangement of respective metal piece structures in each region. The metal sheet structure is uniformly distributed and periodically arranged, and the metal sheet structure is different in different regions, wherein the configuration of the metal sheet structure is mainly adjusted according to the angle of the incident wave. An extremely wide-band multi-channel partial-displacement Cassegrain crossover antenna system as described in claim 1 of the patent application, which includes a plurality of main powers The prime feed horn is a conventional angle or other designed transceiver mechanism, wherein at least one main radio wave transceiver has a signal receiving point at a front end thereof close to the main focus, and each main wave receiving and receiving unit receives the satellite from the corresponding satellite. Radio waves, which penetrate high frequency electric waves of the frequency dividing sub-mirror or emit high frequency electric waves toward the frequency dividing sub mirror. The ultra-wideband multi-channel partial-displacement Cassegrain crossover antenna system according to the first or sixth aspect of the patent application, comprising a plurality of image radio wave transmitting and receiving mechanisms (images), wherein at least one of the image radio wave transmitting and receiving mechanisms The signal receiving point of the front end is close to the image focus for receiving low frequency electric waves reflected from the frequency dividing sub-mirror or transmitting low frequency electric waves toward the frequency dividing sub mirror. For example, the extremely wide-band multi-channel partial-displacement Cassegrain crossover antenna system described in claim 1 of the patent scope, wherein every twenty to thirty degrees is used as a region separation because the metal sheet structure reacts to the incident angle. The change within plus or minus thirty degrees is not too great.