Millimeter wave dual-faced radio frequency transceiver assembly and radar phased array system

Abstract

This invention discloses a millimeter-wave bifacial radio frequency transceiver assembly, comprising: a housing, a first mixing plate, a second mixing plate, a first outer cover plate, and a second outer cover plate. The housing includes a base plate, a first plate body, and a second plate body, which are disposed on both sides of the base plate. The base plate has the first mixing plate and the second mixing plate. The first mixing plate, the base plate, and the second mixing plate are sequentially fixedly connected to form a bifacial structure, and the first mixing plate and the second mixing plate have mirror-symmetrical dimensions. An adapter plate is provided at the slot of the base plate. At least one low-frequency connector is provided on the first plate body, and the low-frequency connector is bonded to the first mixing plate by gold wire bonding. At least an even number of radio frequency connectors are provided on the second plate body. By using a bifacial sandwich symmetrical structure design, the structural deformation and housing breakage problems caused by the mismatch of the thermal expansion coefficients of the structure and the mixing plate in traditional single-sided radio frequency transceiver assemblies are improved under the condition that the antenna array element spacing is the same.

Description

Technical Field

[0001] This invention relates to the field of radio frequency microwave circuit technology, and in particular to a millimeter-wave bifacial radio frequency transceiver assembly and a radar phased array system. Background Technology

[0002] With the increasing complexity of the electromagnetic environment, active phased array radar systems are placing more stringent demands on microwave components, especially with the rise of millimeter-wave radar arrays, which have further reduced the spacing between phased array antenna elements. Excessively low profiles have pushed traditional brick-type components to their space utilization limits, often leading to structural deformation and poor airtightness. Due to space constraints in spaceborne, airborne, and other applications, low profile dimensions are required for components, resulting in limited thickness of the component housing base plate and reduced mechanical strength. Traditional single-sided RF transceiver components are prone to structural deformation and housing fracture due to the mismatch between the structure and the thermal expansion coefficient of the pressure plate. Therefore, it is necessary to design an RF transceiver component that addresses the deformation and electromagnetic environment compatibility issues of low-profile RF transceiver components, suitable for spaceborne, missile-borne, and other radar phased array systems with more stringent space requirements. Summary of the Invention

[0003] The purpose of this invention is to provide a millimeter-wave bifacial radio frequency transceiver assembly and a radar phased array system to solve the deformation problem and electromagnetic environment compatibility problem of low-profile radio frequency transceiver assemblies.

[0004] This invention provides a millimeter-wave bidirectional radio frequency transceiver assembly, comprising: a housing, a first mixing plate, a second mixing plate, a first outer cover plate, and a second outer cover plate.

[0005] The housing includes a base plate and a first plate and a second plate connected to both sides of the base plate. The first plate and the second plate are disposed on both sides of the base plate. A first mixing plate and a second mixing plate are provided on the base plate. The first mixing plate, the base plate, and the second mixing plate are sequentially fixedly connected to form a double-sided structure. The first mixing plate and the second mixing plate are made of the same material and have the same thickness, and their external dimensions are mirror-symmetrical. An adapter plate is provided at the slot of the base plate. The adapter plate is embedded in the slot of the base plate and is electrically interconnected with the first mixing plate and the second mixing plate. At least one low-frequency connector is provided on the first plate, and the low-frequency connector is bonded to the first mixing plate by gold wire bonding. At least an even number of radio frequency connectors are provided on the second plate.

[0006] The shell has a first outer cover plate and a second outer cover plate on its upper and lower surfaces, respectively. The first outer cover plate, together with the first mixing plate, a portion of the first plate body and a portion of the second plate body, forms a first chamber. The second outer cover plate, together with the first mixing plate, a portion of the first plate body and a portion of the second plate body, forms a second chamber.

[0007] Preferably, the adapter plate has several through holes inside, at least two of which are used to transmit power supply voltage, and the other through holes are used to transmit control signals.

[0008] Preferably, the surface of the adapter plate is provided with a soft gold plating layer, the thickness of which is greater than 2 μm; the thickness of the adapter plate is greater than the thickness of the base plate.

[0009] Preferably, one end of the adapter board is connected to the bottom surface of the first mixing plate via BGA solder balls, and the other end of the adapter board is connected to the second mixing plate via gold wire bonding, so as to realize the transmission of power and control signals on both sides.

[0010] Preferably, the first hybrid board includes a first radio frequency board and a first power board, wherein the first radio frequency board is disposed on the upper surface of the first power board and the chip circuit is mounted on the upper surface of the first power board.

[0011] The first radio frequency board has slots in the chip mounting area and the blind hole area of ​​the first power board;

[0012] The chip circuit includes a radio frequency bare chip, and a matching pad is mounted on the bottom surface of the radio frequency bare chip. The pad is mounted on the first power board. After assembly, the bonding area on the upper surface of the radio frequency bare chip is flush with the height of the first radio frequency board.

[0013] The radio frequency bare chip is surrounded by an inner cavity, which is located on the upper surface of the first radio frequency board, and the size of the inner cavity is larger than the slot size of the first radio frequency board.

[0014] Preferably, the second mixing board includes a second radio frequency board and a second power supply board, the second radio frequency board is disposed on the upper surface of the second power supply board, and the chip circuit is mounted on the upper surface of the second power supply board.

[0015] The second RF board has slots in the chip mounting area and the blind via area of ​​the second power board;

[0016] The chip circuit includes a radio frequency bare chip, and a matching pad is installed on the bottom surface of the radio frequency bare chip. The pad is installed on the second power board. After assembly, the bonding area on the upper surface of the radio frequency bare chip is flush with the height of the second radio frequency board.

[0017] The radio frequency bare chip is surrounded by an inner cavity, which is located on the upper surface of the second radio frequency board, and the size of the inner cavity is larger than the slot size of the second radio frequency board.

[0018] Preferably, both the first RF board and the second RF board are provided with several metal layers. The first and second metal layers are RF signal layers, and the third and fourth metal layers are ground planes without etched circuits. Both the first RF board and the second RF board are provided with striplines and microstrip lines. The striplines are located in the second metal layer, and the microstrip lines are located in the first metal layer. The second metal layer is connected to the first metal layer through blind vias to realize the stripline-microstrip line form transformation.

[0019] Preferably, the stripline and microstrip line are provided with a plurality of through holes around them, the through holes connecting the first metal layer to the fourth metal layer, and the microstrip line is connected to the corresponding RF bare chip by gold wire bonding.

[0020] Preferably, both the first power board and the second power board have n metal layers, a plurality of through holes, and at least one type of blind via. The through holes connect to layers 1 to n, and the blind vias connect to layers 1 to n-2. The blind vias are only distributed in the cutout area of ​​the RF board and do not contact the first RF board / second RF board. The nth and n-1th metal layers are ground layers and do not etch signal lines. Wherein, n≥4 and is an even number.

[0021] This invention also provides a radar phased array system, including a millimeter-wave bidirectional radio frequency transceiver assembly as described in the embodiments of this invention. Compared with the prior art, this invention has the following advantages:

[0022] This invention employs a double-sided sandwich symmetrical structural design, which improves upon the structural deformation and shell breakage problems caused by the mismatch in thermal expansion coefficients between the structure and the pressure plate in traditional single-sided RF transceiver components, while maintaining the same antenna array element spacing. The separate circuit design of the RF board and power board, along with the addition of an external cavity for the RF bare chip, effectively improves the electromagnetic environment. The use of an adapter board instead of traditional metal-cased connectors further reduces the component size. This invention is widely applicable to space-borne, missile-borne, and other phased array radar systems with more stringent space requirements. Attached Figure Description

[0023] Figure 1 This is a side view of the dual-sided radio frequency transceiver assembly in an embodiment of the present invention;

[0024] Figure 2 This is a side view of the mixing plate in this embodiment;

[0025] Figure 3 This is a circuit diagram of the first layer of the radio frequency board in the embodiment;

[0026] Figure 4 This is a circuit diagram of the second layer of the radio frequency board in the embodiment;

[0027] Figure 5A top front view of the dual-sided radio frequency transceiver assembly in the embodiment;

[0028] Figure 6 A top view of the rear of the dual-sided radio frequency transceiver assembly in the embodiment;

[0029] In the picture:

[0030] 1. Housing; 8-1 First mixing plate, 8-2 Second mixing plate; 2. Low frequency connector; 3. Radio frequency connector; 4. Adapter board; 6. Inner cavity; 5-1 First outer cover plate, 5-2 Second outer cover plate; 10-1 Radio frequency board; 10-2 Power board; 15. Housing positioning post; 9-2 Radio frequency bare chip; 7. Pad; 9-1 Power management chip; 9-3 Filter capacitor; 11. Stripline; 17. Microstrip line; 12. Blind hole; 13. Through hole. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] like Figure 1 As shown, the dual-sided RF transceiver assembly provided in this embodiment is a 16-channel receiving assembly, including a housing 1, a first mixing plate 8-1, a second mixing plate 8-2 (i.e., upper and lower mixing plates), a low-frequency connector 2, an RF connector 3, an adapter plate 4, an inner cavity 6, a first outer cover plate 5-1, and a second outer cover plate 5-2. The housing 1 includes a base plate and a first plate and a second plate connected to both sides of the base plate, i.e., the left and right sides of the housing 1. The center points of the first plate and the second plate are perpendicularly arranged on both sides of the base plate along their corresponding length directions. The base plate is provided with the first mixing plate 8-1 and the second mixing plate 8-2. The first mixing plate 8-1, the base plate, and the second mixing plate 8-2 are sequentially fixedly connected to form a double-sided structure. The first mixing plate 8-1 and the second mixing plate 8-2 are made of the same material and have the same thickness, and their external dimensions are mirror-symmetrical. The base plate has a slot with an adapter plate 4, which is embedded in the slot and electrically interconnected with the first mixing plate 8-1 and the second mixing plate 8-2. The first plate has at least one low-frequency connector 2, which is bonded to the first mixing plate 8-1 by gold wire bonding. The second plate has at least an even number of radio frequency connectors 3.

[0033] Those skilled in the art will understand that the first mixing plate 8-1 and the first mixing plate 8-2 are made of the same material and have the same thickness, and are mirror images of each other; the first outer cover plate 5-1 and the second outer cover plate 5-2 are mirror images of each other in size; the housing 1 has a positioning post 15, and the mixing plates 8-1 and 8-2 are limited by the positioning post 15 and are respectively welded to the front and back sides of the bottom plate of the housing 1; the low frequency connector 2 is installed on one side of the housing 1 and connected to the mixing plate 8-1 by means of gold wire bonding; the adapter plate 4 is embedded in the slot of the bottom plate of the housing 1; the outer cover plates 5-1 and 5-2 are laser-sealed onto the housing 1 to form a closed cavity with the housing 1; there are a total of n radio frequency glass beads 3 (n≥4 and is an even number), n / 2 on each of the upper and lower sides, and they are evenly distributed on the upper and lower sides of the housing 1.

[0034] The mixing plates on both sides of the housing 1 provided in this embodiment are made of the same material and thickness, and are mirror-symmetrically welded to the front and back sides of the bottom plate of the housing 1, forming a "sandwich" shape with the bottom plate of the housing 1. The low-frequency connector 2 provided in this embodiment is welded to the left side of the housing 1 by high-frequency induction and bonded to the upper mixing plate using gold wire. There are 18 radio frequency glass beads provided in this embodiment, 9 on each side, of which 2 are used as radio frequency input interfaces and the remaining 16 are used as radio frequency output interfaces.

[0035] In one embodiment, the housing 1 is provided with a first outer cover plate 5-1 and a second outer cover plate 5-2 on its upper and lower surfaces, respectively. The first outer cover plate 5-1 forms a first chamber with the first mixing plate 8-1, a portion of the first plate body and a portion of the second plate body, and the second outer cover plate 5-2 forms a second chamber with the first mixing plate 8-1, a portion of the first plate body and a portion of the second plate body.

[0036] The adapter board 4 replaces the metal shell connector, reducing the component size. In one embodiment, the adapter board 4 has several through holes, at least two of which are used to transmit power voltage, and the others are used for control signal transmission. The surface of the adapter board 4 is coated with a soft gold layer, the thickness of which is greater than 2µm; the thickness of the adapter board 4 is greater than the thickness of the base plate. One end of the adapter board 4 is connected to the bottom surface of the first hybrid pressure plate 8-1 via BGA solder balls, and the other end of the adapter board 4 is connected to the second hybrid pressure plate 8-2 via gold wire bonding, so as to realize the transmission of power and control signals on both sides. The solder pads on the surface of the adapter board 4 need to be plated with soft gold, and the gold thickness should be greater than 2µm; the thickness of the adapter board 4 should preferably exceed the thickness of the base plate of the shell 1.

[0037] Those skilled in the art will understand that the adapter board 4 provided in this embodiment is a double-sided board with nine through holes inside. Two of these through holes are used for transmitting power supply voltage, and the remaining through holes are used for transmitting control signals. The adapter board 4 is made of FR4 material, with a thickness of 2mm and a gold-plated surface. One end of the adapter board 4 is embedded in the slot of the bottom plate of the housing and connected to the bottom surface of the pressure mixing board 8-1 using BGA solder balls. The other end is connected to the pressure mixing board 8-2 using gold wire bonding, thereby realizing the transmission of power and control signals from both the top and bottom surfaces.

[0038] Specifically, the first hybrid platen 8-1 and the second hybrid platen 8-2 are both formed by soldering the RF board 10-1 and the power board 10-2 together; the RF board needs to have cutouts in the area around the chip and in the blind via area of ​​the power board; the chip includes an RF bare chip 9-2 and matching pads 7, a power management chip 9-1, and a filter capacitor 9-3; the power management chip 9-1 and the filter capacitor 9-3 are directly attached to the power boards 10-1 and 10-2; the RF bare chip 9-2 and the pads 7 are first... After soldering with high-temperature solder, a lower melting point solder is used to bond the power boards 10-1 and 10-2. The pad 7 has the same or slightly larger dimensions as the RF bare chip 9-2. The material is preferably a metal conductor with high thermal conductivity, such as molybdenum copper, oxygen-free copper, or copper-molybdenum copper. After assembly, the bonding area on the upper surface of the RF bare chip 9-2 should be flush with the height of the RF board. An inner cavity 6 needs to be built around the RF bare chip. The inner cavity 6 should be pasted on the upper surface of the RF boards 10-1 and 10-2, and its size should be larger than the slot size of the RF board.

[0039] In one embodiment, the first mixing plate 8-1 includes a first radio frequency board 10-1 and a first power supply board 10-2, wherein the first radio frequency board is disposed on the upper surface of the first power supply board;

[0040] The first RF board is provided with a bare RF chip and a pad adapted to the bare RF chip. The size of the pad is greater than or equal to the size of the bare RF chip, and the height of the bonding area on the upper surface of the bare RF chip is the same as the height of the first RF board.

[0041] The radio frequency bare chip is surrounded by a corresponding inner cavity 6, which is disposed on the upper surface of the first radio frequency board, and the size of the inner cavity 6 is larger than the slot size of the first radio frequency board.

[0042] The first power board is equipped with a power management chip 9-1 and a filter capacitor 9-3.

[0043] In one embodiment, the second mixing plate 8-2 includes a second radio frequency board and a second power supply board, wherein the second radio frequency board is disposed on the upper surface of the second power supply board;

[0044] The second RF board is provided with a corresponding RF bare chip and a pad adapted to the corresponding RF bare chip. The size of the pad is greater than or equal to the size of the RF bare chip, and the height of the bonding area on the upper surface of the RF bare chip is the same as the height of the second RF board.

[0045] The radio frequency bare chip is surrounded by a corresponding inner cavity 6, which is disposed on the upper surface of the second radio frequency board, and the size of the inner cavity 6 is larger than the slot size of the second radio frequency board.

[0046] The second power board is equipped with a power management chip 9-1 and a filter capacitor 9-3.

[0047] Those skilled in the art will understand that the first mixing plate 8-1 and the second mixing plate 8-2 provided in this embodiment are both composed of two parts: an RF board 10-1 and a power supply board 10-2. See also Figure 2 As shown, the specific implementation method is as follows: cut a first solder piece with the same outer dimensions as the RF board 10-1, cut a second solder piece with the same outer dimensions as the power board 10-2, limit it by the housing positioning post 15, and install the first solder piece-power board-second solder piece-RF board 10-1 in sequence. The installation order on the upper and lower sides is the same, and the matching welding fixture is used for integrated welding.

[0048] In this embodiment, various chips are mounted on the power board. Among them, the RF bare chip 9-2 includes a multi-functional phase-shifting chip and a low-noise amplifier. Both are raised at the bottom by pads 7 before being mounted on the power board. The pads 7 are made of 0.2mm thick copper-molybdenum copper and have the same dimensions as the chips. After being raised by the pads 7, there is no height difference between the RF microstrip line and the RF bare chip 9-2, achieving lossless transmission of RF signals.

[0049] In one embodiment, see Figure 3-6As shown, both the first and second RF boards have several metal layers, such as four layers. The first and second metal layers are RF signal layers, while the third and fourth metal layers are entirely grounded without etched circuitry. Both the first and second RF boards have striplines and microstrip lines. The stripline is located on the second metal layer, and the microstrip line 17 is located on the first metal layer. A blind via connects the second metal layer to the first metal layer, enabling the transformation from stripline 11 to microstrip line 17. Specifically, the RF signal fed into the antenna is sent to the low-noise amplifier via the RF connector 3 port. After amplification, the signal is sent to the dual-channel multi-function chip via the first microstrip line. After phase-shifting and amplification by the multi-function chip, the signal is synthesized by a combining network and output to the low-frequency connector 2 port. The RF board 10-1 provided in this embodiment has four metal layers: L1, L2, L3, and L4. The RF signal fed by the antenna is sent to the low-noise amplifier through the right RF port. After signal amplification, it is sent to the dual-channel multifunction chip via the L1 layer microstrip line 17. The signal is then phase-shifted and amplified by the multifunction chip, and finally synthesized by a combining network before being fed to the left RF port for output. Vias 13 need to be placed around the RF microstrip circuit, especially around the stripline 11, to ensure RF signal integrity. Gold wire bonding connects the L1 layer microstrip line to the dual-channel multifunction chip and the low-noise amplifier.

[0050] In one embodiment, a plurality of vias 13 are provided around the stripline 11 and the microstrip line 17. The vias 13 connect the first metal layer to the fourth metal layer. The microstrip line 17 is connected to the corresponding RF bare chip 9-2 by gold wire bonding.

[0051] In one embodiment, both the first power board and the second power board have n metal layers, several through holes, and at least one type of blind via 12. The through holes 13 connect layers 1 to n, and the blind vias 12 connect layers 1 to n-2. The blind vias 12 are only distributed in the cutout area of ​​the RF board and do not contact the first RF board / second RF board. The nth and n-1th metal layers are ground planes and do not etch signal lines, where n ≥ 4 and is an even number. The first power board and the second power board 10-2 provided in this embodiment, i.e., the power board 10-2 corresponding to the first hybrid plate 8-1 and the second hybrid plate 8-2, have a total of 8 metal layers, namely L1, L2, L3, L4, L5, L6, L7, and L8. L7 and L8 are ground planes and do not etch signal lines. The blind vias 12 connect layers 1 to 6 and are used for signal transmission, and are only distributed in the cutout area of ​​the RF board.

[0052] The present invention also provides a radar phased array system, including a dual-sided radio frequency transceiver component as described in the embodiments of the present invention. The implementation principle is the same as that of the dual-sided radio frequency transceiver component described above, and will not be repeated here.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A millimeter wave dual-sided radio frequency transceiver assembly, comprising: include: The shell, the first mixing plate, the second mixing plate, the first outer cover plate, and the second outer cover plate. The housing includes a base plate and a first plate and a second plate connected to both sides of the base plate. The first plate and the second plate are disposed on both sides of the base plate. A first mixing plate and a second mixing plate are provided on the base plate. The first mixing plate, the base plate, and the second mixing plate are sequentially fixedly connected to form a double-sided structure. The first mixing plate and the second mixing plate are made of the same material and have the same thickness, and their external dimensions are mirror-symmetrical. An adapter plate is provided at the slot of the base plate. The adapter plate is embedded in the slot of the base plate and is electrically interconnected with the first mixing plate and the second mixing plate. At least one low-frequency connector is provided on the first plate, and the low-frequency connector is bonded to the first mixing plate by gold wire bonding. At least an even number of radio frequency connectors are provided on the second plate. The shell has a first outer cover plate and a second outer cover plate on its upper and lower surfaces, respectively. The first outer cover plate, together with the first mixing plate, part of the first plate body and part of the second plate body, forms a first chamber. The second outer cover plate, together with the first mixing plate, part of the first plate body and part of the second plate body, forms a second chamber. The first hybrid board includes a first radio frequency board and a first power supply board. The first radio frequency board is disposed on the upper surface of the first power supply board, and the chip circuit is mounted on the upper surface of the first power supply board. The first radio frequency board has slots in the chip mounting area and the blind hole area of ​​the first power board; The chip circuit includes a radio frequency bare chip, and a matching pad is mounted on the bottom surface of the radio frequency bare chip. The pad is mounted on the first power board. After assembly, the bonding area on the upper surface of the radio frequency bare chip is flush with the height of the first radio frequency board. The radio frequency bare chip is surrounded by an inner cavity, which is located on the upper surface of the first radio frequency board, and the size of the inner cavity is larger than the slot size of the first radio frequency board.

2. The millimeter-wave dual-sided radio-frequency transceiver assembly of claim 1, wherein, The adapter board has several through holes inside, at least two of which are used to transmit power voltage, and the other through holes are used to transmit control signals.

3. The millimeter-wave dual-sided radio-frequency transceiver assembly of claim 1, wherein, The adapter plate has a soft gold plating layer on its surface, and the thickness of the soft gold plating layer is greater than 2 μm; the thickness of the adapter plate is greater than the thickness of the base plate.

4. The millimeter-wave dual-sided radio-frequency transceiver assembly of claim 1, wherein, One end of the adapter board is connected to the bottom surface of the first mixing plate via BGA solder balls, and the other end of the adapter board is connected to the second mixing plate via gold wire bonding, so as to realize the transmission of power and control signals on both sides.

5. The millimeter-wave dual-sided radio-frequency transceiver assembly of claim 1, wherein, The second mixing board includes a second radio frequency board and a second power supply board. The second radio frequency board is disposed on the upper surface of the second power supply board, and the chip circuit is mounted on the upper surface of the second power supply board. The second RF board has slots in the chip mounting area and the blind via area of ​​the second power board; The chip circuit includes a bare radio frequency (RF) chip, and a matching pad is mounted on the bottom surface of the bare RF chip. The pad is installed on the second power board, and after assembly, the bonding area on the upper surface of the RF bare chip is aligned with the height of the second RF board; The radio frequency bare chip is surrounded by an inner cavity, which is located on the upper surface of the second radio frequency board, and the size of the inner cavity is larger than the slot size of the second radio frequency board.

6. The millimeter-wave dual-sided radio-frequency transceiver assembly of claim 5, wherein, Both the first RF board and the second RF board have several metal layers. The first and second metal layers are RF signal layers, and the third and fourth metal layers are ground planes without etched circuits. Both the first RF board and the second RF board have striplines and microstrip lines. The striplines are located in the second metal layer, and the microstrip lines are located in the first metal layer. They are connected to the first metal layer through blind vias to achieve stripline-to-microstrip line transformation.

7. The millimeter-wave dual-sided radio-frequency transceiver assembly of claim 6, wherein, The stripline and microstrip line are provided with several through holes around them. The through holes connect the first metal layer to the fourth metal layer. The microstrip line is connected to the corresponding RF bare chip by gold wire bonding.

8. The millimeter-wave dual-sided radio-frequency transceiver assembly of claim 5, wherein, Both the first power board and the second power board have n metal layers, several through holes, and at least one type of blind via. The through holes connect to layers 1 to n, and the blind vias connect to layers 1 to n-2. The blind vias are only distributed in the cutout area of ​​the RF board and do not contact the first RF board / second RF board. The nth and n-1th metal layers are ground layers and do not etch signal lines. Here, n ≥ 4 and is an even number.

9. A radar phased array system, characterized by, Includes the millimeter-wave bidirectional radio frequency transceiver assembly as described in any one of claims 1-8.

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