A microwave array flat antenna

Abstract

The present invention relates to the technical field of flat antennas, and specifically to a microwave array flat antenna, comprising: a first metal layer, a second metal layer and a third metal layer forming the electric wall of the antenna; a transmitting waveguide port and a receiving waveguide port are arranged on the third metal layer; the opposite surfaces of the second metal layer and the third metal layer are both provided with matching waveguide slots; the transmitting antenna layer is arranged in the waveguide slot, and the second metal layer, the transmitting antenna layer and the third metal layer form a transmitting feed waveguide network; the transmitting feed waveguide network is connected to the transmitting waveguide port. The receiving antenna layer and the transmitting antenna layer of the flat antenna of the present invention are at different levels, so that the receiving and transmitting work in two different frequency bands and work simultaneously without interference. Because the waveguide of the transmitting feed waveguide network is a metal waveguide, the low loss characteristic of the metal waveguide greatly reduces the loss of the large-scale feeding network, thereby significantly improving the transmitting gain, and at the same time, due to the high-pass characteristic of the waveguide, the transmitting and receiving isolation of the antenna is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flat panel antennas, and in particular to a microwave array flat panel antenna. Background Art

[0002] Portable ground satellite communication terminals are small ground satellite stations that provide wireless communication services for areas that are not covered by ground base stations, such as mining areas, pastures and mountainous areas. They are also communication backups for natural disasters and are important guarantees for economic and social development and people's lives and property. As people carry out more and more activities in various geographical environments, the demand for communication anytime and anywhere is growing, and the portability and compactness of satellite terminals have become more prominent. Traditional parabolic antennas cannot meet the demand. In recent years, the industry has focused on the development of flat-panel satellite antennas, whose low-profile features greatly reduce the size and weight compared to parabolic antennas, but the size (portability) determines the antenna gain, and its internal circuit is complex and the microwave loss is high. The gain (efficiency) of flat-panel antennas is usually much smaller than that of parabolic antennas. The wireless access capability of portable satellite terminals is obviously weak. In many scenarios such as rainy weather and cell edges, the communication rate drops significantly or even communication is interrupted, which cannot meet the development of the economy and society and provide reliable communication services.

[0003] Therefore, how to improve the gain of flat antennas is a current research direction. Summary of the invention

[0004] (I) Purpose of the invention

[0005] The object of the present invention is to provide a microwave array flat panel antenna which can improve the gain of the flat panel antenna, improve the transmit-receive isolation of the flat panel antenna and has high integration.

[0006] (II) Technical solution

[0007] To solve the above problems, the present invention provides a microwave array flat antenna, comprising: a first metal layer, a receiving antenna layer, a second metal layer, a transmitting antenna layer and a third metal layer; the first metal layer, the receiving antenna layer, the second metal layer, the transmitting antenna layer and the third metal layer are stacked in sequence from top to bottom;

[0008] The first metal layer, the second metal layer and the third metal layer constitute an electrical wall of the antenna;

[0009] The third metal layer is provided with a transmitting waveguide port and a receiving waveguide port;

[0010] The first metal layer, the receiving antenna layer and the second metal layer constitute a receiving feed network, and the receiving feed network is used to receive a first signal and transmit the received first signal to the receiving waveguide port;

[0011] The opposing surfaces of the second metal layer and the third metal layer are both provided with matching waveguide grooves;

[0012] The transmitting antenna layer is arranged in the waveguide slot, and the second metal layer, the transmitting antenna layer and the third metal layer constitute a transmitting feed waveguide network;

[0013] The transmitting feed waveguide network is in communication with the transmitting waveguide port, and the transmitting waveguide port transmits the signal to be transmitted to the transmitting feed waveguide network.

[0014] In another aspect of the present invention, preferably, the receiving feed network includes a plurality of first array elements and a low noise amplifier, and the signals received by the plurality of first array elements are pre-synthesized or not synthesized, low-noise amplified and then synthesized step by step to a common receiving branch, and then transitionally transmitted to the receiving waveguide port via a microstrip waveguide;

[0015] The transmitting feed waveguide network is configured as a differential waveguide feed network, and the transmitting feed waveguide network includes a plurality of levels of E-plane T-type waveguide power distribution structures and E-plane microstrip waveguide transition structures; the E-plane microstrip waveguide transition structure includes a plurality of second array elements, and the signal to be transmitted is input from the transmitting waveguide port, and is power-divided step by step to the second array element through the E-plane T-type waveguide power distribution structure and the E-plane microstrip waveguide transition structure.

[0016] In another aspect of the present invention, preferably, the transmitting feed waveguide network waveguide is an E-plane T-shaped rectangular waveguide, and the transmitting antenna layer is arranged at the long side of the transmitting feed waveguide network waveguide.

[0017] In another aspect of the present invention, preferably, the E-plane microstrip waveguide transition structure is configured as an E-plane dual-probe microstrip waveguide transition array.

[0018] In another aspect of the present invention, preferably, when the power of the signal to be transmitted is distributed to the second array element step by step, there is a phase difference of 180 degrees in each step.

[0019] In another aspect of the present invention, preferably, the E-plane dual-probe microstrip waveguide transition array is arranged on the transmitting antenna layer, and the probe of the second array element of the E-plane dual-probe microstrip waveguide transition array is inserted into the E-plane of the transmitting feed waveguide network waveguide.

[0020] In another aspect of the present invention, preferably, the four ends of the end of the E-plane T-type waveguide power distribution structure are connected to the second array element of the E-plane dual-probe microstrip waveguide transition array, and the second array element includes a positive phase probe branch and a negative phase probe branch, and the positive phase probe branch and the negative phase probe branch have opposite phases.

[0021] In another aspect of the present invention, preferably, the second array element further comprises a positive phase shifter and a negative phase shifter, and the positive phase shifter and the negative phase shifter have opposite phases;

[0022] The positive phase shifter is connected to the positive phase probe branch, and the negative phase shifter is connected to the negative phase probe branch.

[0023] In another aspect of the present invention, preferably, the receiving antenna layer comprises: a first array element, a microstrip circuit and a low noise amplifier;

[0024] The first array element and the low noise amplifier are integrated in the microstrip circuit;

[0025] The received signal passes through the first array element and the low noise amplifier in sequence, is synthesized multiple times in stages, and is transmitted to the receiving waveguide port.

[0026] In another aspect of the present invention, preferably, the low noise amplifier is configured as a common mode input low noise amplifier.

[0027] (III) Beneficial effects

[0028] The above technical solution of the present invention has the following beneficial technical effects:

[0029] The receiving antenna layer and the transmitting antenna layer of the flat antenna of the present invention are at different levels, and the array elements of the transmitting and receiving antennas are arranged orthogonally, so that the receiving and transmitting work in two different frequency bands and work simultaneously without interference. The receiving signal is synthesized from the receiving low-noise receiving feed network to the receiving waveguide port, and the loss of the receiving network is greatly reduced, thereby significantly reducing the receiving noise of the antenna and achieving high-gain reception; the transmitting signal is fed from the transmitting waveguide port to each array element through the transmitting feed waveguide network waveguide. Because the waveguide of the transmitting feed waveguide network is a metal waveguide, the low-loss characteristic of the metal waveguide greatly reduces the loss of the large-scale feeding network, thereby significantly improving the transmission gain. At the same time, due to the high-pass characteristic of the waveguide, the transmitting and receiving isolation of the antenna is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0031] Figure 2 is a top view of a third metal layer according to an embodiment of the present invention;

[0032] Figure 3 is a bottom view of a second metal layer according to an embodiment of the present invention;

[0033] Figure 4 Schematic diagram of an E-plane dual-probe microstrip waveguide transition array according to an embodiment of the present invention;

[0034] Figure 5 is a schematic diagram of the end of an E-plane T-type waveguide power distribution structure according to an embodiment of the present invention;

[0035] Figure 6 is a schematic diagram of a receiving antenna layer according to an embodiment of the present invention;

[0036] Figure 7 is a schematic diagram of a receiving and feeding network according to an embodiment of the present invention;

[0037] Figure 8 This is the simulated value diagram of the transmission gain of the traditional flat antenna;

[0038] Fig. 9 is a diagram of transmission gain simulation values ​​according to an embodiment of the present invention;

[0039] Reference numerals:

[0040] 1: first metal layer, 2: second metal layer, 3: third metal layer, 4: receiving antenna layer, 5: transmitting antenna layer, 6: transmitting waveguide port, 7: receiving waveguide port, 8: end of E-plane T-type waveguide power distribution structure, 9: positive phase probe branch, 10: negative phase probe branch, 11: positive phase shifter, 12: negative phase shifter, 13: low noise amplifier. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0042] The accompanying drawings show schematic diagrams of layer structures according to embodiments of the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clarity. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0043] Obviously, the described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be noted that the terms “first”, “second” and “third” are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0045] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0046] The present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0047] Embodiment 1

[0048] A microwave array flat panel antenna, Figure 1 FIG. 1 shows a schematic diagram of the overall structure of an embodiment of the present invention. Figure 1 As shown, it includes: a first metal layer 1, a receiving antenna layer 4, a second metal layer 2, a transmitting antenna layer 5 and a third metal layer 3, which are stacked in sequence from top to bottom; the first metal layer 1, the receiving antenna layer 4, the second metal layer 2, the transmitting antenna layer 5 and the third metal layer 3 are screwed in sequence to form a flat antenna with a single port input and a single port output; the first metal layer 1, the second metal layer 2 and the third metal layer 3 form a metal wall of the antenna including a receiving feed network and a transmitting feed waveguide network;

[0049] The third metal layer 3 is provided with a transmitting waveguide port 6 and a receiving waveguide port 7;

[0050] The first metal layer 1, the receiving antenna layer 4 and the second metal layer 2 constitute a receiving feed network, and the receiving feed network is used to receive the first signal and transmit the received first signal to the receiving waveguide port 7;

[0051] The opposing surfaces of the second metal layer 2 and the third metal layer 3 are both provided with matching waveguide grooves; the transmitting antenna layer 5 is provided in the waveguide groove, and the second metal layer 2, the transmitting antenna layer 5 and the third metal layer 3 constitute a transmitting feed waveguide network; Figure 2 is a top view of a third metal layer according to an embodiment of the present invention; Figure 3 is a bottom view of the second metal layer of one embodiment of the present invention; Figure 2 and Figure 3As shown, the second metal layer 2 and the third metal layer 3 are hollowed out and provided with matching waveguide grooves, and the two are combined to form a complete waveguide groove. The second metal layer 2 and the third metal layer 3 have waveguide grooves, and the transmitting antenna layer 5 is set therein, locked and pressed to form a transmitting path waveguide feeding network, and the transmitting feeding waveguide network is connected to the transmitting waveguide port 6, and the transmitting waveguide port 6 transmits the signal to be transmitted to the transmitting feeding waveguide network, so as to realize the excitation of each array element from the transmitting waveguide port 6 to the transmitting feeding waveguide network. In this embodiment, the transmitting antenna layer 5 and the receiving antenna layer 4 are both set as PCB; the receiving antenna layer and the transmitting antenna layer of the flat antenna are at different levels, and the first array element and the second array element are orthogonally arranged, so that the receiving and transmitting work in two different frequency bands and work simultaneously without interference.

[0052] Figure 4 is a schematic diagram of an E-plane dual-probe microstrip waveguide transition array according to an embodiment of the present invention, Figure 5 FIG. 1 is a schematic diagram showing an end portion of an E-plane T-type waveguide power distribution structure according to an embodiment of the present invention. Figure 6 is a schematic diagram of a receiving antenna layer according to an embodiment of the present invention. Figure 4 , Figure 5 and Figure 6 As shown, the receiving feed network includes a plurality of first array elements and a low noise amplifier. The signals received by the plurality of first array elements are synthesized in advance or not, and then low-noise amplified and synthesized step by step to a common receiving branch, and then transmitted to the receiving waveguide port 7 via a microstrip waveguide transition; the step-by-step synthesis is that two first array elements synthesize a first synthesis sub-path, two first synthesis sub-paths synthesize a second synthesis sub-path, two second synthesis sub-paths synthesize a third synthesis sub-path, and so on.

[0053] The receiving antenna layer 4 is integrated with the following components through the SMT process: the first array element, the microstrip circuit and the low-noise amplifier 13; the first array element and the low-noise amplifier are integrated in the microstrip circuit; the received signal passes through the first array element and the low-noise amplifier 13 in sequence, and then is synthesized multiple times step by step and transmitted to the common main path and connected to the receiving waveguide port 7 through the microstrip waveguide transition structure; the received signal is synthesized to the receiving waveguide port 7 after being passed through the low-noise amplifier 13, and the loss of the feeding network is greatly reduced, thereby significantly reducing the receiving noise of the antenna and achieving high-gain reception; the front low-noise amplifier can greatly improve the sensitivity of the receiving link.

[0054] Furthermore, in this embodiment, the low noise amplifier 13 is a common mode input architecture, and the common mode low noise amplifier circuit integrates the combining and matching design, that is, the impedance transformation characteristics brought by the power combining are used to design the dual-input single-output low noise amplifier 13, the input matching is simplified and the performance is good, which can further improve the sensitivity of the receiving antenna, and the circuit layout is more matched with the compact cross-shaped structure of this case, which solves the problem of difficult circuit layout in a narrow space, simplifies the difficulty of circuit layout and reduces the noise coefficient of the receiving path. For different power allocation ratios, two low noise amplifiers with input power allocation ratios of 1:1 and 1:2 are designed. Figure 7 FIG. 4 shows a schematic diagram of a receiving feed network according to an embodiment of the present invention. Figure 7 As shown, it is a low noise amplifier with an input power allocation ratio of 1:2; the low noise amplifier pre-stage increases the gain of the antenna and reduces the noise temperature of the antenna itself. The G / T (ratio of antenna gain to system noise) value, an indicator that characterizes the receiving performance, will be further improved.

[0055] In this embodiment, a 280-element receiving (frequency band 10.7-12.8GHz) and transmitting (frequency band 13.75-14.5GHz) flat panel antenna is taken as an example, assuming that the antenna element gain of a single element is Ga, the loss corresponding to the feeder length a is La, La is 128mm, the loss corresponding to the feeder length b is Lb is 358mm, the unit length loss is 0.065dB / 10mm, the measured synthetic loss is 0.1dB per level, considering 3-level synthesis, the loss corresponding to the Lb length is about 2.627dB. The parameters of this embodiment and the conventional antenna technical parameters are calculated as follows:

[0056] The total gain of a conventional flat antenna (without considering the low noise amplifier array condition) is G = 10*logN + Ga-La-Lb; Tn is the noise temperature of the antenna element, Ta is the noise temperature corresponding to the feeder length a, Tb is the noise temperature corresponding to the feeder length b, Tn is the noise temperature from the antenna array to the active reference plane, and Tnf is the noise temperature of the receiver; G / T = (10*logN + Ga-La-Lb) (dB) / (Tn + Ta + Tb + Tnf);

[0057] The total gain of the low noise amplifier of this embodiment is: G'=10*logN+Ga-La; G / T'=(10*logN+Ga-La)(dB) / (Tn+Ta+Tnf);

[0058] The antenna gain of this embodiment will be higher than G'-G=Lb=2.7dB, and the receiving gain of the antenna is significantly improved. In engineering practice, a rough estimate can be made:

[0059] G=30dB,Tn=0.2dB=13.5K,Ta=0.9dB=66.5K,Tb=2.7dB=250K,Tnf=0.8dB=60K,then G / T=2.56,G / T'=13.3,an improvement of 10.74.

[0060] A common-mode low-noise amplifier array is formed by multiple common-mode low-noise amplifiers, in which the low-noise amplifier is located closer to the first array element. The input matching of the low-noise amplifier adopts a common-mode design. The receiving antenna layer and the low-noise amplifier array and its power management circuit are designed on a whole PCB to avoid the feeder loss of the external low-noise amplifier and make assembly simpler and more convenient.

[0061] The transmitting feed waveguide network is configured as a differential waveguide feed network, and the transmitting feed waveguide network includes several levels of E-plane T-type waveguide power distribution structures and E-plane microstrip waveguide transition structures; the E-plane microstrip waveguide transition structure includes several second array elements, and the signal to be transmitted is input from the transmitting waveguide port 6, and is power-divided step by step to the second array element through the E-plane T-type waveguide power distribution structure and the E-plane microstrip waveguide transition structure.

[0062] The step-by-step power division is to divide the signal to be transmitted into two first power sub-paths, the first power sub-path is divided into the second power sub-path, the second power sub-path is divided into the third power sub-path, and so on. The transmitting feed waveguide network waveguide is an E-plane T-type rectangular waveguide, and the transmitting antenna layer 5 is arranged at the long side of the transmitting feed waveguide network waveguide. The E-plane microstrip waveguide transition structure is arranged as an E-plane double probe microstrip waveguide transition array, and the E-plane double probe microstrip waveguide transition array includes a plurality of second array elements. The E-plane T-type waveguide power distribution structure connects each second array element in the E-plane double probe microstrip waveguide transition array step by step. The E-plane T-type waveguide power distribution structure is connected to the transmitting waveguide port 6, and when the signal to be transmitted is power-divided step by step, there is a 180-degree phase difference in each stage. The E-plane double probe microstrip waveguide transition array is arranged on the transmitting antenna layer 5, and the probe of the second array element of the E-plane double probe microstrip waveguide transition array is inserted into the E-plane of the transmitting feed waveguide network waveguide. The end 8 of the E-plane T-type waveguide power distribution structure is set in an "I" shape. The four ends of the end 8 of the E-plane T-type waveguide power distribution structure are connected to the second array element of the E-plane double-probe microstrip waveguide transition array. The second array element includes a positive phase probe branch 9 and a negative phase probe branch 10. The positive phase probe branch 9 and the negative phase probe branch 10 have opposite phases. Figure 4As shown, the signal is converted from the waveguide cavity and the power is distributed into two signals, namely the positive phase probe branch 9 and the negative phase probe branch 10, and propagates in the two microstrips. Due to the field distribution characteristics of the E-plane double-probe microstrip waveguide transition, the phases of the positive phase probe branch 9 and the negative phase probe branch 10 are opposite, which is the first phase inversion. The second array element also includes a positive phase shifter 11 and a negative phase shifter 12, and the phases of the positive phase shifter 11 and the negative phase shifter 12 are opposite; the negative phase shifter 12 can be obtained by rotating the positive phase shifter 11 by 180 degrees; this is a secondary phase inversion, the positive phase shifter 11 is connected to the positive phase probe branch 9, and the negative phase shifter 12 is connected to the negative phase probe branch 10, so that the positive phase shifter 11 and the positive phase probe branch 9 and the negative phase shifter 12 and the negative phase probe branch 10 achieve secondary phase inversion, and achieve equal amplitude in-phase excitation.

[0063] The secondary phase inversion of this embodiment realizes the same-phase and equal-amplitude excitation of the second array element by the transmitting feed waveguide network, achieving the ideal condition of the array antenna. The metal waveguide is a low-loss transmission line, and its loss is much lower than that of the microstrip line, and it can still have low loss at a longer feed line length; therefore, the transmission gain of the flat antenna is significantly improved, and the high-gain problem under a larger number of array elements is solved. The high-pass characteristics of the metal waveguide make the signal in the receiving frequency band in a decay mode state, which can achieve excellent isolation and avoid interference with the receiver. The pre-blocking filter of the receiver can be removed, and the filter can be redesigned or other devices can be integrated in the waveguide, making the receiving link more sensitive. Furthermore, the transmitting feed waveguide network, that is, the differential waveguide feeding network, has a simple implementation process. A groove is cut between the two metal plates to leave an embedding space for the transmitting antenna layer, and then it is locked and assembled without increasing the volume and weight of the antenna.

[0064] The core technical indicators of a radio system are the G / T value and the EIRP value, which are jointly determined by the antenna and the transceiver. The G / T value and the EIRP value of this embodiment have been improved on these two core indicators without increasing the volume, area and weight, and without losing any portability. In this embodiment, a flat antenna with 280 second array elements is taken as an example: Figure 8 A diagram showing the simulated value of the transmission gain of a traditional flat panel antenna is shown; Fig. 9 FIG. 4 shows a transmission gain simulation value diagram of an embodiment of the present invention; Figure 8 and Fig. 9 As shown,

[0065] In this embodiment, the receiving gain is increased by 2.7 dB, and the receiving G / T is estimated to be improved by 10.74. Communication can be established in a more severe signal environment, and the receiving performance of small-diameter portable terminals is greatly improved;

[0066] The transmission gain of this embodiment is improved by about 2dB, which is equivalent to reducing the transmitter power by 2dB. The power, power consumption and heat generation of the transmitter are greatly reduced, and the volume and weight of the system are also greatly reduced, and the battery life is significantly improved.

[0067] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

[0068] In the above description, the technical details of patterning and etching of each layer are not described in detail. However, those skilled in the art should understand that various means in the prior art can be used to form layers, regions, etc. of desired shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not completely the same as the methods described above.

[0069] The present invention has been described above with reference to the embodiments of the present invention. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, a person skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

[0070] Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.

[0071] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A microwave array flat antenna, characterized in that: include: A first metal layer (1), a receiving antenna layer (4), a second metal layer (2), a transmitting antenna layer (5) and a third metal layer (3); the first metal layer (1), the receiving antenna layer (4), the second metal layer (2), the transmitting antenna layer (5) and the third metal layer (3) are stacked in sequence from top to bottom; The first metal layer (1), the second metal layer (2) and the third metal layer (3) constitute the electrical wall of the antenna; The third metal layer (3) is provided with a transmitting waveguide port (6) and a receiving waveguide port (7); The first metal layer (1), the receiving antenna layer (4) and the second metal layer (2) constitute a receiving feed network, and the receiving feed network is used to receive a first signal and transmit the received first signal to the receiving waveguide port (7); The opposing surfaces of the second metal layer (2) and the third metal layer (3) are both provided with matching waveguide grooves; The transmitting antenna layer (5) is arranged in the waveguide slot, and the second metal layer (2), the transmitting antenna layer (5) and the third metal layer (3) constitute a transmitting feed waveguide network; The transmitting feed waveguide network is in communication with the transmitting waveguide port (6), and the transmitting waveguide port (6) transmits the signal to be transmitted to the transmitting feed waveguide network; The receiving feed network comprises a plurality of first array elements and a low noise amplifier. The signals received by the plurality of first array elements are pre-synthesized or not pre-synthesized, low-noise amplified and then synthesized step by step to a common receiving branch, and then transferred to the receiving waveguide port (7) via a microstrip waveguide transition. The transmitting feed waveguide network is set as a differential waveguide feed network, and the transmitting feed waveguide network includes a plurality of levels of E-plane T-type waveguide power distribution structures and E-plane microstrip waveguide transition structures; the E-plane microstrip waveguide transition structure includes a plurality of second array elements, and the signal to be transmitted is input from the transmitting waveguide port (6), and is power-divided step by step to the second array element through the E-plane T-type waveguide power distribution structure and the E-plane microstrip waveguide transition structure.

2. The planar antenna according to claim 1, characterized in that: The transmitting feed waveguide network waveguide is an E-plane T-shaped rectangular waveguide, and the transmitting antenna layer (5) is arranged at the long side of the transmitting feed waveguide network waveguide.

3. The planar antenna according to claim 1, characterized in that: The E-plane microstrip waveguide transition structure is configured as an E-plane double-probe microstrip waveguide transition array.

4. The planar antenna according to claim 1, characterized in that: When the power of the signal to be transmitted is distributed to the second array element step by step, there is a 180-degree phase difference in each step.

5. The planar antenna according to claim 4, characterized in that: The E-plane double-probe microstrip waveguide transition array is arranged on the transmitting antenna layer (5), and the probe of the second array element of the E-plane double-probe microstrip waveguide transition array is inserted into the E-plane of the transmitting feed waveguide network waveguide.

6. The planar antenna according to claim 5, characterized in that: The four ends of the end (8) of the E-plane T-type waveguide power distribution structure are all connected to the second array element of the E-plane dual-probe microstrip waveguide transition array, and the second array element includes a positive phase probe branch (9) and a negative phase probe branch (10), and the positive phase probe branch (9) and the negative phase probe branch (10) have opposite phases.

7. The planar antenna according to claim 6, characterized in that: The second array element further comprises a positive phase shifter (11) and a negative phase shifter (12), wherein the phases of the positive phase shifter (11) and the negative phase shifter (12) are opposite; The positive phase shifter (11) is connected to the positive phase probe branch (9), and the negative phase shifter (12) is connected to the negative phase probe branch (10).

8. The planar antenna according to claim 1, characterized in that: The receiving antenna layer (4) comprises: a first array element, a microstrip circuit and a low noise amplifier (13); The first array element and the low noise amplifier are integrated in the microstrip circuit; The received signal passes through the first array element and the low noise amplifier (13) in sequence, is synthesized multiple times in stages, and is then transmitted to the receiving waveguide port (7).

9. The planar antenna according to claim 8, characterized in that: The low noise amplifier is configured as a common mode input low noise amplifier.

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