Board card amplitude-frequency characteristic calibration device and test machine

Abstract

The utility model relates to a board card amplitude-frequency characteristic calibration device and a test machine, and the device comprises a signal receiving and transmitting module which is connected with a channel of a TX link module in a board card, receives multi-tone signals of different frequency points outputted by the channel of the TX link module, and outputs TX link calibration original data; the loopback link module is connected with the channel of the TX link module and the channel of the RX link module in the board card, and transmits the multi-tone signal output by the channel of the TX link module to the corresponding channel of the RX link module; and the upper computer is connected with the signal receiving and transmitting module and the channel of the RX link module in the board card, receives the TX link calibration original data output by the signal receiving and transmitting module, and performs data acquisition on the multi-tone signals of different frequency points output by the channel of the RX link module to obtain RX link calibration original data. A signal source is not needed to calibrate the receiving link, so that the occupied external instrument resources can be reduced, and the calibration cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor testing, in particular to a board card amplitude-frequency characteristic calibration device and a test machine. BACKGROUND

[0002] The analog-digital hybrid board card in the test machine has consistency problems due to its own devices, etc., and has different amplitude-frequency characteristics, i.e., flatness problems. If calibration is not performed or the calibration effect is not good, not only the power accuracy of a single tone will be affected, but also the performance of a wideband modulation signal (such as WLAN, LTE, etc.) will deteriorate, and therefore amplitude-frequency characteristic calibration needs to be performed to ensure the performance of the board card.

[0003] The traditional test machine board card amplitude-frequency characteristic calibration scheme mainly relies on external power meters to perform transmit chain calibration, uses signal sources to perform receive chain calibration, and then receives data related to the transmit chain and the receive chain by an upper computer to perform calibration, which greatly occupies external instrument resources and increases calibration costs. CONTENT OF THE INVENTION

[0004] Therefore, it is necessary to provide a board card amplitude-frequency characteristic calibration device and a test machine capable of reducing calibration costs in view of the above problems.

[0005] The first aspect of the present application provides a board card amplitude-frequency characteristic calibration device, comprising:

[0006] A signal transceiver module is connected to a channel of a TX chain module in a board card, receives multi-tone signals of different frequencies output by the channel of the TX chain module, and outputs TX chain calibration raw data.

[0007] A loopback chain module is connected to the channel of the TX chain module and a channel of an RX chain module in the board card, and transmits the multi-tone signals output by the channel of the TX chain module to the corresponding channel of the RX chain module.

[0008] An upper computer is connected to the signal transceiver module and the channel of the RX chain module in the board card, receives the TX chain calibration raw data output by the signal transceiver module, and collects data of multi-tone signals of different frequencies output by the channel of the RX chain module to obtain RX chain calibration raw data.

[0009] The TX chain calibration raw data is used for amplitude-frequency characteristic calibration of the TX chain module of the board card, and the RX chain calibration raw data is used for amplitude-frequency characteristic calibration of the RX chain module of the board card.

[0010] In one of the embodiments, the signal transceiver module is a baseband signal transceiver, which receives the multi-tone signals output by the differential channels or single-ended channels of the TX link module for data collection and outputs the TX link calibration raw data to the host computer.

[0011] The host computer collects the multi-tone signals output by the differential channels or single-ended channels of the RX link module for data collection and obtains the RX link calibration raw data.

[0012] In one of the embodiments, the host computer is further connected to the RX link module and the TX link module in the board card, and adjusts the amplitude level and frequency point of the RX link module and the TX link module.

[0013] The signal transceiver module receives the multi-tone signals of each frequency point output by the channels of the TX link module at different amplitude levels, and outputs the TX link calibration raw data corresponding to the amplitude level to the host computer. The host computer receives the multi-tone signals of each frequency point output by the channels of the RX link module at different amplitude levels for data collection, and obtains the RX link calibration raw data corresponding to the amplitude level.

[0014] In one of the embodiments, the host computer is further connected to the storage module in the board card, and sends the calibration parameters of each channel of the RX link module and the TX link module to the storage module for storage.

[0015] The second aspect of the application provides a test machine, which comprises a board card and the board card amplitude-frequency characteristic calibration device described above. The board card comprises a TX link module and an RX link module, and the loopback link module is arranged in the board card. The channels of the TX link module are connected to the signal transceiver module and connected to the channels of the RX link module through the loopback link module.

[0016] In one of the embodiments, the TX link module comprises a DAC, an output amplitude control unit and a single-ended / differential output control unit connected in sequence. The single-ended / differential output control unit is connected to the signal transceiver module and the loopback link module. The host computer is connected to the DAC, the output amplitude control unit and the single-ended / differential output control unit.

[0017] In one of the embodiments, the TX link module further comprises an output LPF switching unit. The DAC is connected to the output amplitude control unit through the output LPF switching unit.

[0018] In one of the embodiments, the RX link module comprises an ADC, a receiving amplitude control unit and a single-ended / differential receiving control unit connected in sequence, the single-ended / differential receiving control unit is connected to the loopback link module, and the upper computer is connected to the ADC, the receiving amplitude control unit and the single-ended / differential receiving control unit.

[0019] In one of the embodiments, the RX link module further comprises a receiving LPF switching unit, and the ADC is connected to the receiving amplitude control unit through the receiving LPF switching unit.

[0020] In one of the embodiments, the tester further comprises a tester port, and the TX link module is connected to the tester port through a signal transmission cable, and the tester port is connected to the signal transceiver module through a signal transmission cable.

[0021] The above-mentioned board card amplitude-frequency characteristic calibration device and tester use the loopback link module to connect the channel of the TX link module and the channel of the RX link module in the board card, use the signal transceiver module to receive the multi-tone signals of different frequencies output by the channel of the TX link module, output the TX link calibration raw data to the upper computer, the upper computer collects the multi-tone signals of different frequencies output by the channel of the RX link module to obtain the RX link calibration raw data, and the data required for calibrating the amplitude-frequency characteristics of the TX link module and the RX link module in the board card can be obtained, and the receiving link calibration can be performed without using a signal source, thereby reducing the occupation of external instrument resources and reducing the calibration cost. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structural block diagram of the board card amplitude-frequency characteristic calibration device in one of the embodiments;

[0023] Figure 2 It is a structural schematic diagram of the board card amplitude-frequency characteristic calibration device in one of the embodiments;

[0024] Figure 3 It is an external calibration schematic diagram of the board card amplitude-frequency characteristic calibration device in one of the embodiments;

[0025] Figure 4 It is an internal calibration schematic diagram of the board card amplitude-frequency characteristic calibration device in one of the embodiments;

[0026] Figure 5 It is a calibration flowchart of the board card amplitude-frequency characteristic calibration device in one of the embodiments. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing specific embodiments only and is not intended to be limiting of the application.

[0029] It can be understood that, in the following embodiments, “connection” should be understood as “electrical connection”, “communication connection” and the like if the circuits, modules, units and the like connected with each other have transmission of electrical signals or data.

[0030] As used herein, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. It should also be understood that the term “comprising” or “including” or “having” and the like, designate the presence of stated features, integers, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, operations, components, parts, or combinations thereof.

[0031] The board card in the current test machine has multiple channels and multiple gears to meet the requirement of test efficiency. The channels are generally 16 or 32, or even more. Not only the single channel of the board card has flatness problem, but also different flatness exists among different board cards, different channels and different gears. At present, the amplitude-frequency characteristic calibration of the board card in the test machine mainly relies on external use of a power meter for transmission link calibration and a signal source for receiving link calibration, which increases the cost of calibration. Moreover, different gears of each channel need to be detected and calibrated, and each time only a single frequency point of a single gear of a single channel can be calibrated. A board card needs to be calibrated for hundreds of times, and the calibration time is relatively long. In the traditional calibration scheme, on the one hand, since the power meter and the signal source are single-ended devices, only single-ended amplitude-frequency characteristic calibration can be performed, and differential amplitude-frequency characteristic calibration cannot be performed. On the other hand, since the power meter and the signal source are generally single-channel devices, and the power meter can only perform single-tone calibration and cannot perform multi-tone signal calibration, the efficiency of amplitude-frequency characteristic calibration is very low. Assuming that the number of channels in the board card is N, the number of gears is M, and the number of calibration frequency points is K; the power meter collects once or the signal source transmits once, and the board card collects once, which is regarded as one calibration action, then the entire scheme needs to complete N×M×K×2×2 calibration actions.

[0032] In one embodiment, a board card amplitude-frequency characteristic calibration device is provided. The board card can be an analog-digital hybrid board card, such as Figure 1As shown, the device comprises a signal transceiver module 110, a loopback link module 120 and a host computer 130. The signal transceiver module 110 is connected to the channels of the TX (transmit) link module 210 in the board card 200, receives the multi-tone signals of different frequencies output by the channels of the TX link module 210, and outputs the TX link calibration raw data. The loopback link module 120 is connected to the channels of the TX link module 210 and the channels of the RX (receive) link module 220 in the board card 200, and transmits the multi-tone signals output by the channels of the TX link module 210 to the corresponding channels of the RX link module 220. The host computer 130 is connected to the signal transceiver module 110 and the channels of the RX link module 220 in the board card 200, receives the TX link calibration raw data output by the signal transceiver module 110, and collects the multi-tone signals of different frequencies output by the channels of the RX link module 220 to obtain the RX link calibration raw data.

[0033] The TX link calibration raw data is used for amplitude-frequency characteristic calibration of the TX link module 210 in the board card 200, and the RX link calibration raw data is used for amplitude-frequency characteristic calibration of the RX link module 220 in the board card 200. The loopback link module 120 can be arranged inside the board card to facilitate link connection. The host computer 130 can include, but is not limited to, a workstation or an industrial computer that meets the performance requirements of the tester. The board card can include, but is not limited to, an analog-digital hybrid board card or a radio frequency board card. The host computer 130 processes the TX link calibration raw data and the RX link calibration raw data to obtain calibration parameters, or sends the data to an external processor for calibration and receives the calibration parameters returned by the external processor.

[0034] The specific type of the signal transceiver module 110 is not unique. In this embodiment, the signal transceiver module 110 is a baseband signal transceiver, which collects the multi-tone signals output by the differential channels or single-ended channels of the TX link module 210 to output the TX link calibration raw data to the host computer 130. The host computer 130 collects the multi-tone signals output by the differential channels or single-ended channels of the RX link module 220 to obtain the RX link calibration raw data. The baseband signal transceiver can receive the multi-tone signals output by the differential channels or single-ended channels of the TX link module 210, and can support simultaneous reception of multi-channel differential channels or single-ended channels for data collection, thereby realizing calibration of the differential channels or single-ended channels of the board card.

[0035] Further, the host computer 130 is also connected to the RX link module 220 and the TX link module 210 in the board card 200, and adjusts the amplitude level and the frequency point of the RX link module 220 and the TX link module 210. The signal transceiver module 110 receives the multi-tone signals of each frequency point output by the TX link module 210 at different amplitude levels, and outputs the TX link calibration raw data corresponding to the amplitude level to the host computer 130; the host computer 130 receives the multi-tone signals of each frequency point output by the RX link module 220 at different amplitude levels for data acquisition, and obtains the RX link calibration raw data corresponding to the amplitude level. It can be understood that in another embodiment, the RX link module 220 and the TX link module 210 can also be adjusted by other controllers.

[0036] Specifically, the host computer 130 adjusts the amplitude level of each channel of the TX link module 210, and outputs multi-tone signals of different frequency points at the corresponding amplitude level. The baseband signal transceiver receives the differential or single-ended multi-tone signals for data acquisition, obtains the TX link calibration raw data corresponding to the amplitude level, and sends it to the host computer 130 for analysis to obtain the calibration parameters of each channel of the TX link module 210, and completes the external calibration. Then, the host computer 130 sets the amplitude level of the TX link module 210, controls the TX link module 210 to output differential or single-ended multi-tone signals at different frequency points, and transmits them to the RX link module 220 through the loopback link module 120. The host computer 130 adjusts the amplitude level of each channel of the RX link module 220, and based on the received multi-tone signals of each frequency point at different amplitude levels, it performs data acquisition to obtain the RX link calibration raw data corresponding to the amplitude level, and analyzes it to obtain the calibration parameters of each channel of the RX link module 220, and completes the internal calibration, that is, the external calibration is completed first, and then the internal calibration is completed. In addition, the host computer 130 is also connected to the storage module 230 in the board card 200, and sends the calibration parameters of each channel of the RX link module 220 and the TX link module 210 to the storage module 230 for storage.

[0037] In one embodiment, continuing to refer to Figure 1A test machine is also provided, including a board 200 and the aforementioned board amplitude-frequency characteristic calibration device. Board 200 includes a TX link module 210 and an RX link module 220. A loopback link module 120 is disposed within board 200. The channel of the TX link module 210 is connected to the signal transceiver module 110, and is connected to the channel of the RX link module 220 through the loopback link module 120. Board 200 may also include a storage module 230 for storing calibration parameters. Furthermore, the test machine includes a test machine port 300. The TX link module 210 is connected to the test machine port 300 via a signal transmission cable, and the test machine port 300 is connected to the signal transceiver module 110 via a signal transmission cable. In actual testing scenarios, the test machine port 300 can also be connected to the channel of the RX link module 220 via a signal transmission cable to transmit external signals to the RX link module 220.

[0038] In one embodiment, such as Figure 2 As shown, the TX link module 210 includes a DAC (digital-to-analog converter), an output amplitude control unit 214, and a single-ended / differential output control unit 216 connected in sequence. The single-ended / differential output control unit 216 is connected to the signal transceiver module 110 and the loopback link module 120. The host computer 130 is connected to the DAC, the output amplitude control unit 214, and the single-ended / differential output control unit 216. The output amplitude control unit 214 includes positions 1, 2, ..., and M. The host computer can send commands to the output amplitude control unit 214 to adjust the amplitude position, and then control the DAC to output multi-tone signals at different frequency points. After corresponding amplitude adjustment, the signals are output by the single-ended / differential output control unit 216. The single-ended / differential output control unit 216 can be composed of a switching switch. The host computer 130 sends instructions to the single-ended / differential output control unit 216 to control the output of differential or single-ended signals. The output signals can be transmitted to the signal transceiver module 110 through the test machine port 300, or to the corresponding channel of the RX link module 220 through the loopback link module 120.

[0039] Furthermore, the TX link module 210 may also include an output LPF (low-pass filter) switching unit 212, through which the DAC is connected to the output amplitude control unit 214. For each pair of differential channels (CH1_p and CH1_n, CH2_p and CH2_n, ..., CHN_p and CHN_n) of the TX link module 210, a DAC, an output LPF switching unit 212, an output amplitude control unit 214, and a single-ended / differential output control unit 216 may be correspondingly configured. The output LPF switching unit 212 may include multiple LPFs (e.g., LPF1 and LPF2) and corresponding series-connected switching switches. Each LPF2 and LPF1 has a corresponding switching switch at its input and output terminals. The switching switches at the input terminals of LPF2 and LPF1 are connected to the DAC, and the switching switches at the output terminals of multiple LPF2 and LPF1 are all connected to the output amplitude control unit 214. The host computer 130 can also be connected to the switching switch in the output LPF switching unit 212 to send commands to switch the LPF in each channel. That is, the host computer 130 can control the signal frequency, LPF switching, amplitude level switching and differential or single-ended output of each pair of differential channels of the TX link module 210.

[0040] In one embodiment, the RX link module 220 includes an ADC (analog-to-digital converter), a receiving amplitude control unit 224, and a single-ended / differential receiving control unit 226 connected in sequence. The single-ended / differential receiving control unit 226 is connected to the loopback link module 120, and the host computer 130 is connected to the ADC, the receiving amplitude control unit 224, and the single-ended / differential receiving control unit 226. The single-ended / differential receiving control unit 226 is also composed of a switch. The host computer 130 sends commands to the single-ended / differential receiving control unit 226 to control the reception of differential or single-ended signals. The receiving amplitude control unit 224 includes position 1, position 2, ..., position M. The host computer sends commands to the receiving amplitude control unit 224 to adjust the amplitude position, and then receives the multi-tone signals of each frequency point output by the ADC for data acquisition to obtain the original RX link calibration data for the corresponding amplitude position.

[0041] Loopback link module 120 includes, but is not limited to, such as Figure 2 The onboard loopback transmission line connects the corresponding switch ports in the single-ended / differential output control unit 216 and the single-ended / differential receiver control unit 226.

[0042] Further, the RX link module 220 further comprises a receiving LPF switching unit 222, and the ADC is connected to the receiving amplitude control unit 224 through the receiving LPF switching unit 222. For each pair of differential channels (CH1_p and CH1_n, CH2_p and CH2_n, …, CHN_p and CHN_n) of the RX link module 220, the ADC, the receiving LPF switching unit 222, the receiving amplitude control unit 224 and the single-ended / differential receiving control unit 226 can be correspondingly arranged. The receiving LPF switching unit 222 can comprise a plurality of LPFs (for example, LPF1 and LPF2) and corresponding serially connected switching switches. Each of the input end and the output end of each LPF2 and LPF1 is respectively provided with a corresponding switching switch. The switching switch at the input end of the LPF2 and the LPF1 is connected to the ADC, and the switching switches at the output ends of the plurality of LPF2 and LPF1 are all connected to the receiving amplitude control unit 224. The host computer 130 is further connected to the switching switches in the receiving LPF switching unit 222, and sends a command to switch the LPF in each channel. That is, the host computer 130 can control the LPF switching, the amplitude gear switching and the differential or single-ended output of each pair of differential channels of the RX link module 220.

[0043] The board card amplitude-frequency characteristic calibration device provided in the application increases the baseband signal transceiver, the loopback link module 120 (inside the board card), and the host computer 130 to realize the calibration function. The remaining modules are the basic functions of the test machine itself and the port expansion function module. The baseband signal transceiver supports simultaneous input and output of two differential or single-ended signals. The input part IQ in is divided into I+, I-, Q+ and Q-. I+, I- and Q+, Q- are two independent differential channels, which can simultaneously receive two differential or single-ended signals. The loopback link module 120 is used to loopback the TX link module 210 and the RX link module 220 inside the board card to calibrate the RX link. The host computer 130 is responsible for the board card link switching, the control and data transmission of the baseband signal transceiver, the storage and issuance of calibration parameters and the like in the entire calibration process.

[0044] The entire calibration process is divided into external calibration and internal calibration. External calibration targets the TX link module 210, and internal calibration targets the RX link module 220. During external calibration, the baseband transceiver's signal input ports are I+, I-, Q+, and Q-. Ports I+ and I- connect to the differential channels CH1_p and CH1_n of the TX link module 210, and Q+ and Q- connect to the differential channels CH2_p and CH2_n of the TX link module 210. The communication interface of the baseband transceiver is then connected to the host computer 130 via a standard communication cable to achieve parallel calibration of the dual channels of the TX link module. During internal calibration, the TX link module 210 and the RX link module 220 are connected together via the loopback link module 120 to achieve parallel calibration of all RX link modules 220. The following sections describe the external and internal calibration processes separately:

[0045] External calibration:

[0046] like Figure 3 As shown, the two differential channels of the TX link module 210 (hereinafter referred to as TX link) are connected to the baseband signal transceiver at port 300 of the test machine.

[0047] ① Based on the TX link calibration frequency, the two channels of the TX link on the board are configured to transmit in differential mode, and then the corresponding multi-tone signals are transmitted simultaneously. The baseband transceiver can collect the original calibration data of all frequency points of the differential mode of the two channels in a single step in one acquisition.

[0048] ② Switch the TX link level to change the transmission amplitude, and repeat step ① to traverse all levels.

[0049] ③ Based on the TX link calibration frequency, the two channels of the board's TX link are configured to transmit in single-ended mode, and then the corresponding multi-tone signals are transmitted simultaneously. The baseband transceiver can collect the original calibration data of all frequency points of a single gear in single-ended mode of the two channels in one acquisition.

[0050] ④ Switch the TX link level to change the transmission amplitude, and repeat step ③ to traverse all levels.

[0051] To complete the external calibration, you need to manually connect the cable N / 2 times, and the baseband signal transceiver needs to collect N*M / 2 (differential) + N*M (single-ended) data times to complete the calibration data collection of the amplitude-frequency characteristics of all TX links.

[0052] Internal calibration:

[0053] like Figure 4 As shown by the green line, the TX link module 210 (hereinafter referred to as TX link) and the RX link module 220 (hereinafter referred to as RX link) are looped together inside the board through the loopback link module 120. The connection method of other channels is the same and is not shown in the figure.

[0054] ① According to the frequency point calibrated by the RX link, configure all channels of the TX link of the board card to transmit differential mode, and simultaneously transmit the corresponding multi-tone signal. Configure all channels of the RX link to collect differential mode single position all frequency point calibration original data at one time.

[0055] ② Switch the RX link position, change the TX link transmission amplitude, and repeat step ① to traverse all positions.

[0056] ③ According to the frequency point calibrated by the RX link, configure all channels of the TX link of the board card to transmit single-ended P mode, and simultaneously transmit the corresponding multi-tone signal. Configure all channels of the RX link to collect single-ended mode single position all frequency point calibration original data at one time.

[0057] ④ Switch the RX link position, change the TX link transmission amplitude, and repeat step ③ to traverse all positions.

[0058] ⑤ Configure TX and RX link all channels to single-ended N, repeat steps ③ and ④.

[0059] To complete the internal calibration, 0 times of manual connection cable is required, and no external instruments and devices are required. The RX link needs to be collected M(differential) + 2*M(single-ended) times, that is, the calibration data collection of the amplitude-frequency characteristics of all RX links can be completed.

[0060] The calibration process flow is shown in Figure 5 , and the specific steps are as follows:

[0061] 1. According to the hardware characteristics of the board card and the order of the digital filter, confirm the frequency points that need to be calibrated for the TX link module 210 (referred to as TX link) and the RX link module 220 (referred to as RX link), such as 1MHz to 100MHz, step 1MHz, then 100 frequency points need to be calibrated, 1MHz, 2MHz, 3MHz, …, 100MHz.

[0062] 2. Configure the board card, host computer, and baseband signal transceiver to be in a normal working state.

[0063] 3. Connect TX link channels CH1 and CH2 to the baseband signal transceiver through external calibration signal transmission cable, as shown in Figure 3 .

[0064] 4. Configure TX link channels CH1 and CH2 to differential mode, select position 1, and transmit the corresponding multi-tone signal according to step 1. The transmission amplitude is set to 80% of the maximum amplitude of the position (this amplitude is the amplitude after the multi-tone superposition, not the single tone amplitude).

[0065] 5. The two TX link channels connected in step 3 transmit simultaneously according to step 4. The baseband transceiver is configured to receive the two channels simultaneously to obtain the time domain data of the I and Q channels. The I channel is the calibration raw data of channel CH1 position 1, and the Q channel is the TX link calibration raw data of channel CH2 position 1.

[0066] 6. On the host computer 130, perform FFT (Fast Fourier Transform) on the raw calibration data of the TX link in position 1 of channel CH1 to obtain the power values ​​of 100 frequency points. Assuming the power value of the 1MHz frequency point is A in dB, and the calibration frequency point loss (insertion loss) of the external calibration signal transmission cable is known, assuming the 1MHz frequency point is B in dB, then the actual calibration parameter for 1MHz is AB. Process other frequency points similarly to the 1MHz frequency point to obtain the calibration parameters for all frequency points, store them inside the board, and use them to generate digital filters for overall broadband compensation in actual use. Referring to channel CH1, obtain and store the calibration parameters for position 1 of channel CH2.

[0067] 7. Following steps 4 to 6, traverse all differential modes of the TX link connection channel in step 3 to obtain the calibration parameters of all differential modes of these two channels.

[0068] 8. Configure TX link channels CH1 and CH2 as single-ended P mode, select gear 1, and follow step 1 to configure the transmission of multi-tone signals at the corresponding frequency points. Set the transmission amplitude to 50% of the maximum amplitude of the gear (this amplitude is the amplitude after the multi-tone is superimposed, not the amplitude of a single tone).

[0069] 9. Repeat steps 4 to 6 to obtain the calibration parameters for all single-ended P values ​​for both channels.

[0070] 10. Configure TX link channels CH1 and CH2 as single-ended N mode, select gear 1, and follow step 1 to configure the transmission of multi-tone signals at the corresponding frequency points. Set the transmission amplitude to 50% of the maximum amplitude of the gear (this amplitude is the amplitude after the multi-tone is superimposed, not the amplitude of a single tone).

[0071] 11. Repeat steps 4 to 6 to obtain the calibration parameters for all single-ended N values ​​for both channels.

[0072] 12. Following steps 3 to 11, traverse all channels to complete the calibration and parameter storage of the TX link.

[0073] 13. Connect all channels of the TX and RX links through the loopback module 120 inside the board, such as... Figure 4 As shown.

[0074] 14. Configure all channels of the TX and RX links to differential mode. Select the maximum amplitude level for the TX link and the level 1 for the RX link. Configure the transmission of multi-tone signals at the corresponding frequency points according to step 1. Set the transmission amplitude to 50% of the maximum amplitude of level 1 on the RX link. If this cannot be achieved, set it to the maximum amplitude (this amplitude is the amplitude after the multi-tone is superimposed, not the amplitude of a single tone).

[0075] 15. The data collected by the RX link is the raw data for calibration of differential mode level 1 of each channel.

[0076] 16. On the host computer 130, perform FFT on the raw calibration data of RX link channel CH1, position 1, to obtain the power values ​​of 100 frequency points. Assume the power value of 1MHz frequency point is A (in dB). The calibration frequency loss of the signal transmission cables inside the TX link board is known; assume the power value of 1MHz frequency point is B (in dB). The calibration frequency loss of the signal transmission cables inside the RX link board is known; assume the power value of 1MHz frequency point is C (in dB). Then the actual calibration parameters for 1MHz are ABC. Other frequency points are processed with reference to the 1MHz frequency point to obtain the calibration parameters for all frequency points. These parameters are stored inside the board for use in generating digital filters for overall broadband compensation during actual use. Referring to channel CH1, other channels also refer to channel CH1 to obtain and store the calibration parameters for position 1.

[0077] 17. Following steps 14 to 16, traverse all channels and all differential modes of the RX link to obtain the calibration parameters for all channels and all differential modes.

[0078] 18. Configure all channels of the TX and RX links to single-ended P mode. Select the maximum amplitude level for the TX link and the level 1 for the RX link. Configure the transmission of multi-tone signals at the corresponding frequency points according to step 1. Set the transmission amplitude to 50% of the maximum amplitude of level 1 on the RX link. If this cannot be achieved, set it to the maximum amplitude (this amplitude is the amplitude after the multi-tone is superimposed, not the amplitude of a single tone).

[0079] 19. Following steps 14 to 16, traverse all channels and all positions of the RX link in single-ended P mode to obtain the calibration parameters for all single-ended P modes of all channels.

[0080] 20. Configure all channels of the TX and RX links to single-ended N mode. Select the maximum amplitude level for the TX link and the level 1 for the RX link. Configure the transmission of multi-tone signals at the corresponding frequency points according to step 1. Set the transmission amplitude to 50% of the maximum amplitude of level 1 on the RX link. If this cannot be achieved, set it to the maximum amplitude (this amplitude is the amplitude after the multi-tone is superimposed, not the amplitude of a single tone).

[0081] 21. According to steps 14 to 16, traverse all channels and all gears of the RX link to obtain the calibration parameters of all channels and all single-ended N modes.

[0082] 22. All calibrations are completed.

[0083] The above-mentioned board card amplitude-frequency characteristic calibration device and test machine can complete calibration using a baseband signal transceiver, reducing the dependence on external instruments. The differential and single-ended are calibrated separately, and the calibration parameters are stored and called separately, which is more suitable for actual use scenarios. The amplitude-frequency characteristic calibration of the entire board card is better, the precision and flatness are better, and the performance of the entire board card is better. The external calibration can be performed in parallel in double channels, and the internal calibration can be performed in parallel in all channels, greatly reducing the channel circulation and greatly reducing the complexity of calibration and cost. The multi-tone calibration is used, and then the calibration coefficient is calculated using an algorithm to perform digital wideband compensation. Once the calibration parameters of all frequency points can be obtained, and the frequency point circulation is not required, greatly reducing the calibration acquisition action. The signal transmission cable introduced in external calibration and ignored in internal calibration are compensated correspondingly, reducing the calibration difficulty while ensuring the precision. Moreover, the present application supports internal calibration, which can be performed without relying on external instruments and equipment during client maintenance, ensuring the precision.

[0084] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not contradict, they should be considered as the scope of the present application.

[0085] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the utility model patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A board card amplitude-frequency characteristic calibration device, characterized by, The application relates to a board card amplitude-frequency characteristic calibration device. The signal transceiver module is connected with the TX link module channel of the board card and receives the multi-tone signals of different frequencies output by the TX link module channel, and outputs TX link calibration original data. The loopback link module is connected with the TX link module channel and the RX link module channel of the board card, and transmits the multi-tone signals output by the TX link module channel to the corresponding channel of the RX link module. The host computer is connected with the signal transceiver module and the RX link module channel of the board card, receives the TX link calibration original data output by the signal transceiver module, and collects the multi-tone signals of different frequencies output by the RX link module channel to obtain RX link calibration original data. The TX link calibration original data is used for amplitude-frequency characteristic calibration of the TX link module of the board card, and the RX link calibration original data is used for amplitude-frequency characteristic calibration of the RX link module of the board card.

2. The apparatus of claim 1, wherein, The signal transceiver module is a baseband signal transceiver, collects the multi-tone signals output by the differential channel or single-end channel of the TX link module, and outputs the TX link calibration original data to the host computer. The host computer collects the multi-tone signals output by the differential channel or single-end channel of the RX link module to obtain the RX link calibration original data.

3. The apparatus of claim 1, wherein, The host computer is also connected with the RX link module and the TX link module of the board card, and adjusts the amplitude level and the frequency of the RX link module and the TX link module. The signal transceiver module receives the multi-tone signals of each frequency output by the channel of the TX link module at different amplitude levels, outputs the TX link calibration original data corresponding to the amplitude level to the host computer, and the host computer receives the multi-tone signals of each frequency output by the channel of the RX link module at different amplitude levels to collect the RX link calibration original data corresponding to the amplitude level.

4. The apparatus of any one of claims 1-3, wherein, The host computer is also connected with the storage module of the board card, and transmits the calibration parameters of each channel of the RX link module and the TX link module to the storage module for storage.

5. A testing machine characterized by, The application also relates to a board card amplitude-frequency characteristic calibration device.

6. The testing machine of claim 5, wherein, The TX link module comprises a DAC, an output amplitude control unit and a single-end / differential output control unit connected in sequence, the single-end / differential output control unit is connected with the signal transceiver module and the loopback link module, and the host computer is connected with the DAC, the output amplitude control unit and the single-end / differential output control unit.

7. The testing machine of claim 6, wherein, The TX link module further comprises an output LPF switching unit, and the DAC is connected with the output amplitude control unit through the output LPF switching unit.

8. The testing machine of claim 5, wherein, The RX link module comprises an ADC, a receiving amplitude control unit and a single-ended / differential receiving control unit connected in sequence, the single-ended / differential receiving control unit is connected with the loopback link module, and the upper computer is connected with the ADC, the receiving amplitude control unit and the single-ended / differential receiving control unit.

9. The testing machine of claim 8, wherein, The RX link module further comprises a receiving LPF switching unit, and the ADC is connected with the receiving amplitude control unit through the receiving LPF switching unit.

10. The testing machine of any of claims 5-9, wherein, Further comprising a tester port, the TX link module is connected with the tester port through a signal transmission cable, and the tester port is connected with the signal transceiver module through a signal transmission cable.

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