Low-cost high-integration active motherboard based on 5G application

Abstract

According to the invention, the air-to-ground mobile communication antenna is systematically analyzed, and the low-cost and high-integration active motherboard based on 5G application is provided, can perform self-trimming and self-inspection, and has high adjacent channel signal-to-noise ratio and vector error. Through reasonable design, modules such as a transceiving link, a feeder network and an antenna unit are integrated in a limited size, vertical polarization and horizontal polarization bidirectional work is realized, and meanwhile, a pure receiving path is integrated, so that the antenna can be used for adjacent cell measurement. And the mother board adopts a high and low frequency mixed voltage form, so that reasonable transmission of C-band signals is realized, and radio frequency path loss is reduced. The active integrated mother board is designed based on low cost, and the antenna for mobile communication is integrally mounted on the belly of a civil aviation, so that the requirement of civil aviation cost control is met.

Description

Technical Field

[0001] The present invention belongs to the field of radio technology, and in particular relates to a low-cost and highly integrated active motherboard based on 5G applications. Background Art

[0002] 5G mobile communication is based on the 5G network era and is based on the standard. The so-called 5G refers to the fifth generation of mobile phone mobile communication standards, which mainly brings us the fifth generation of mobile communication. In a sense, the 5G network has stronger scalability than 4G, and can bring people a more comfortable user experience. Moreover, because 5G communication is very reliable, it can effectively improve people's satisfaction and sense of security in using mobile communications, and meet the requirements of some users for high-speed transmission. 5G technology can not only give people a new experience, but also effectively improve the efficiency and performance of infrastructure, and lay the foundation for the development of various industries at present. Moreover, it can also drive the development of information technology in my country, accelerate the update of equipment, and drive the development of my country's economy. At present, 5G network communication technology has received deep attention from the country and the whole society. Not only my country, but also other countries are increasing human, material and financial resources to strengthen the research and development of this technology to promote economic development.

[0003] In recent years, with the advent of the information age, people have higher and higher requirements for wireless communication technology. Mobile phones are the most typical representative of the information age. Mobile phones and other wireless communication devices are frequently used. Therefore, the wide coverage of mobile phone signals is becoming more and more important. At present, mobile phone communication can only complete signal transmission through ground base stations, and air-to-ground mobile communication signal transmission cannot be achieved. Summary of the invention

[0004] To this end, the present invention conducts a systematic analysis of air-to-ground mobile communication antennas and proposes a low-cost active integrated motherboard based on 5G applications, which can perform self-adjustment and self-checking and has high adjacent channel signal-to-noise ratio and vector error.

[0005] The specific technical solution of the active motherboard of the present invention is as follows:

[0006] 1) Single-channel transmission and reception self-test is realized through integrated coupling network.

[0007] 2) By integrating a multifunctional chip, the amplitude and phase of the active array's multiple vertical polarization channels, horizontal polarization channels and pure receiving channels can be adjusted, and array-level adjustment compensation can be achieved.

[0008] 3) Through power back-off design, the RF link of the active motherboard operates in the linear region, effectively reducing the leakage of the transmission channel to nearby new signals and achieving better network performance indicators.

[0009] Through reasonable design, the present invention integrates modules such as transceiver links, feeder networks and antenna units in a limited size, realizes bidirectional operation of vertical polarization and horizontal polarization, and integrates a pure receiving path, which can be used for neighboring area measurement. The motherboard adopts the form of high-low frequency mixing to realize the reasonable transmission of C-band signals and reduce RF path loss. The active integrated motherboard is based on low-cost design, and the mobile communication antenna is installed on the belly of the civil aviation aircraft to meet the cost control needs of civil aviation.

[0010] The beneficial effects of the present invention are

[0011] 1. Have the ability of self-test.

[0012] 2. Ability to adjust amplitude and phase.

[0013] 3. High adjacent channel signal-to-noise ratio and low vector error enable better carrier signal transmission.

[0014] 4. Compared with traditional C-band active arrays, the array has higher integration and lower cost. Based on communication needs, it can be widely used in various civil aircraft. The entire antenna can realize 5G network communication on civil aircraft and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the active motherboard installation.

[0016] Figure 2 Figure 2 is a schematic diagram of the active motherboard link.

[0017] Figure 3 This is a circuit block diagram of a multifunctional chip.

[0018] Figure 4 A schematic diagram of the monitoring network. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0020] The active motherboard of the present invention is mainly used to realize the amplification of the receiving and transmitting signals. A block design is adopted, and every four vertical polarization channels are synthesized, every four horizontal polarization channels are synthesized, and every four pure receiving channels are synthesized. For vertical polarization, when receiving, after the signal is fed by the antenna, it first passes through the coupler direct path, and then passes through the C-band ultra-narrowband bandpass filter, and is fed into the multifunctional chip shared by the receiving and transmitting. After the signal is amplified, it is synthesized by the one-to-four power division network inside the printed board and then output; when transmitting, after the signal is fed into the printed board by the SMA, it first passes through the one-to-four power division network inside the printed board, and is fed into the multifunctional chip shared by the receiving and transmitting. After the signal is amplified, it passes through the C-band ultra-narrowband bandpass filter and the coupler direct path, and is fed to the antenna for external radiation; the horizontal polarization link is consistent with the vertical polarization direction link except for the difference in the antenna part. For the pure receiving channel, the multifunctional chip transmission enable is grounded, and the multifunctional chip only works in the receiving state. At the same time, a low-noise amplifier chip is added to the link to amplify the signal to ensure the full link gain of the receiving link.

[0021] 1) Coupling network implementation and self-diagnosis

[0022] The coupling network is implemented as Figure 4 As shown in the figure, the coupler adopts a stripline architecture design. Each transceiver multifunctional chip corresponds to a coupler, and every 4 couplers are interconnected to form a coupling network. The coupler isolation termination resistor is matched, and the coupling end is output through the printed circuit board and transmitted to the signal synthesis module. The signal synthesis module can detect the coupling signal and determine the working status of the channel. The coupler can achieve 20dBc coupling. During transmission, the host computer control instruction gives a certain channel to open, and the signal is injected from the corresponding polarization port by the host computer and sent to the corresponding channel of the corresponding array through the transmission link. The signal returns to the signal synthesis module through the coupling monitoring loop. The signal synthesis module channel selection switch switches to the sampling link for sampling, and the result is sent back to the host computer through OOK; during reception, the host computer control instruction gives a certain channel to open, and the signal enters the corresponding receiving RF link from the antenna, and is finally sent to the host computer, which performs corresponding detection by the host computer.

[0023] 2) Amplitude and phase adjustment realization and capability

[0024] The multifunctional chip integrated in the active motherboard can realize amplified transmission and reception, and integrates phase shifters, attenuators, switches, power amplifiers and modulation circuits. When transmitting, the excitation signal is fed into the multifunctional chip, passes through six-digit numerically controlled attenuators, six-digit numerically controlled phase shifters, and then passes through the power amplifier and the transceiver switch for output; when receiving, the echo signal is received by the antenna radiation unit and enters the chip, and then passes through the transceiver switch, low noise amplifier, six-digit numerically controlled phase shifters, and six-digit numerically controlled attenuators for output. The schematic diagram and principle block diagram of the multifunctional chip are shown in the figure below. Figure 4The multifunctional chip can achieve a maximum of 31.5dB transmit and receive attenuation control, with a step of 0.5dB; a maximum of 354.375° phase control, with a step of 5.625°. The amplitude and phase of different channels can be adjusted according to usage to achieve better RF performance.

[0025] 3) High adjacent channel signal-to-noise ratio and low vector error

[0026] Any general RF device, whether it is a mixer, amplifier, isolator or other device, its adjacent channel leakage ratio is affected by the third-order intermodulation distortion of the device. The relationship between the third-order intermodulation product of the device and the third-order intercept point is as follows: IMD3 = (3*P m )-(2*OIP3)(1);

[0027] Where Pm = the power of each tone in the two-tone test; IMD3 = third-order IM3, in dBm, represents absolute units; OIP3 = third-order intermodulation intercept point. represents absolute power.

[0028] For convenience, the formula can be rewritten as relative IMD3, which is IM3 performance related to power level (P):

[0029] IMD3=2*(P m -OIP3) (2);

[0030] The ACLR of a wideband carrier is related to the two-tone IMD3 performance through a correction factor. This correction exists because the IMD3 performance causes a degradation in the ACLR performance. This degradation is due to the effects of various intermodulation products that make up the spectral density of the spread spectrum carrier:

[0031] ACLR n =IMD3+C n (3)

[0032] ACLR n =(2*(P-3)-OIP3))+C n (4)

[0033] Where Ptot = total output power of all carriers in dBm; OIP3 = device OIP3 in dBm; ACLRn = ACLR of “n” carrier in dBc; Cn can be referred to the following table:

[0034] Table 1 Relationship between the number of carriers and weighted values

[0035] Number of carriers Cn 1 2 3 4 9 Weighted value +3 +9 +11 +12 +13

[0036] It can be seen from the formula that when the carrier power is fixed, the greater the absolute value of ACLR (negative value), the greater the OIP3. Therefore, in order to achieve a better ACLR index, the OIP3 of the amplifier needs to be as large as possible. At the same time, EVM is related to the nonlinearity of the amplifier, and EVM decreases as the power of the nonlinear product decreases. Therefore, when designing the active motherboard, the multifunctional chip selected should have a higher OIP3. At the same time, the multifunctional chip is returned to the linear region for use, achieving a better adjacent channel signal-to-noise ratio and vector error.

[0037] The present invention is not limited to the above specific implementations, and the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made to the above implementations based on the technical essence of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-cost, highly integrated active motherboard based on 5G applications, characterized by: It includes a multifunctional chip, a coupler, a C-band ultra-narrowband bandpass filter, and a one-to-four power division network. The multifunctional chip integrates four vertical polarization channels, four horizontal polarization channels, and four pure receiving channels; For vertical polarization, when receiving, after the signal is fed into the antenna, it first passes through the coupler direct path, and then passes through the C-band ultra-narrowband bandpass filter, and is fed into the multifunctional chip shared by the transmitter and receiver. After the signal is amplified, it is synthesized through the one-to-four power division network inside the printed circuit board and then output; when transmitting, after the signal is fed into the printed circuit board by SMA, it first passes through the one-to-four power division network inside the printed circuit board, and is fed into the multifunctional chip shared by the transmitter and receiver. After the signal is amplified, it passes through the C-band ultra-narrowband bandpass filter and the coupler direct path, and is fed to the antenna for external radiation; the horizontal polarization link is consistent with the vertical polarization direction link; for the pure receiving channel, the multifunctional chip transmit enable is grounded, and the multifunctional chip only works in the receiving state; at the same time, a low-noise amplifier chip is added to the link to amplify the signal to ensure the full link gain of the receiving link.

2. A low-cost, highly integrated active motherboard based on 5G applications according to claim 1, characterized in that: The coupler adopts a stripline architecture, each multifunctional chip corresponds to a coupler, and every 4 couplers are interconnected to form a coupling network; the coupler isolation termination resistors are matched, and the coupling end is output through the printed circuit board and then transmitted to the signal synthesis module, which detects the coupling signal and determines the working status of the channel; During transmission, a control instruction from the host computer is given to open a certain channel, and the signal is injected by the host computer from the corresponding polarization port, sent to the corresponding channel of the corresponding array through the transmission link, and the signal returns to the signal integration module through the coupling monitoring loop. The signal integration module path selection switch switches to the sampling link for sampling, and the result is sent back to the host computer through OOK; during reception, a control instruction from the host computer is given to open a certain channel, and the signal enters the corresponding receiving RF link from the antenna and is finally sent to the host computer, which performs corresponding detection.

3. A low-cost, highly integrated active motherboard based on 5G applications according to claim 2, characterized in that: The multifunctional chip integrated in the active motherboard can transmit and receive signals, and integrates the functions of phase shifter, attenuator, switch, power amplifier and modulation circuit. When transmitting, the excitation signal is fed into the multifunctional chip, passes through the digitally controlled attenuator and digitally controlled phase shifter, and then is output through the power amplifier and transceiver switch. When receiving, the echo signal is received by the antenna radiation unit and enters the multifunctional chip, and then is output through the transceiver switch, low noise amplifier, digitally controlled phase shifter and digitally controlled attenuator.

4. A low-cost, highly integrated active motherboard based on 5G applications according to claim 3, characterized in that: The multifunctional chip has a higher OIP3, and the multifunctional chip is returned to the linear region for use, thereby achieving a better adjacent channel signal-to-noise ratio and vector error.

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