Impedance converter of network cable analyzer

Abstract

The utility model relates to the technical field of network cable analyzer calibration, in particular to an impedance converter of a network cable analyzer, which comprises two RJ45 adapter interfaces, four N-type radio frequency interfaces and four impedance conversion modules, each N-type radio frequency interface is connected with the input end of one impedance conversion module, and the other N-type radio frequency interface is connected with the output end of the other impedance conversion module. The output end of each impedance conversion module is connected with the two RJ45 adapters respectively; the impedance conversion module comprises a first balun transformer, a second balun transformer and a third balun transformer, the first balun transformer is connected with the second balun transformer and the third balun transformer in sequence, the first balun transformer is used for achieving impedance conversion and conversion of unbalanced end signals and differential balance signals, and the second balun transformer is used for achieving differential balance signals. And the second balun transformer and the third balun transformer are used for dividing one path of input into three paths of output. According to the utility model, broadband measurement requirements of calibration of a network cable analyzer can be met, full-project calibration of different regulation requirements can be completed, and the problem of characteristic impedance matching of 100 omega or 150 omega of the characteristic impedance of a twisted pair is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to network cable analyzer calibration technical field, concretely relates to a network cable analyzer impedance converter. BACKGROUND

[0002] Network cable analyzer is composed of test host and remote two parts, the host of cable analyzer produces signal, and receives the signal that remote sends back carries out data analysis processing, and remote responds to the host and sends back signal.Network cable analyzer is used for testing LAN physical layer parameter, network wiring quality, is applied to network early wiring installation or solves subsequent fault, maintains network, is the necessary analysis instrument that is used to authentication test, determines each item of wiring system and reaches the requirement of national or international standard transmission performance index.

[0003] The measurement object of network cable analyzer is twisted pair, and the twisted pair is the most commonly used transmission medium in network wiring engineering, which is composed of four pairs of copper wires with insulating protective layer.With the development of economic society, the demand of each industry for information fast transmission is increasing, at present, the upper limit of the measurement frequency of the new network cable analyzer is expanded to nearly 2000MHz, and eight category twisted pair can be measured, but the current network cable analyzer calibration specification (JJF 1494-2014) only stipulates the transmission performance requirement and calibration method of 1-250MHz frequency range.At present, some researches on network cable analyzer calibration method, including the research on network cable analyzer insertion loss, return loss, near-end crosstalk calibration, the research on network cable analyzer far-end attenuation crosstalk ratio calibration method, only the calibration of transmission performance below 250MHz frequency point is studied, and the designed impedance converter only covers the frequency point below 250MHz.According to the requirement of network cable analyzer calibration specification (JJF 1494-2014), the network cable analyzer is determined by the characteristics of the transmission cable twisted pair, and the particularity of the cable analyzer parameters and interface.The interface of network cable analyzer is RJ45 type module, which has eight signals, and the characteristic impedance of twisted pair is 100Ω or 150Ω, not 50Ω and 75Ω.Therefore, in order to meet the requirement of network cable measurement technology development, an impedance converter meeting the calibration requirement of high-frequency network cable analyzer is needed to solve the impedance matching problem. UTILITY MODEL CONTENTS

[0004] In order to solve the technical problems existing in the prior art, the utility model provides, by using the balun converter as the main component, a passive impedance converter is made, which can meet the wideband measurement requirement of high-frequency network cable analyzer calibration, can convert the network line signal of 100Ω or 150Ω characteristic impedance RJ45 interface to 50Ω characteristic impedance interface, and solve the characteristic impedance matching problem of twisted pair.

[0005] The utility model discloses the following technical scheme is adopted to realize:

[0006] A network cable analyzer impedance converter, it includes: two RJ45 switching interfaces, 4 N type radio frequency interfaces and 4 impedance conversion modules, and each N type radio frequency interface is connected with the input end of an impedance conversion module respectively, and the output end of each impedance conversion module is connected with two RJ45 switching interfaces respectively, two RJ45 switching interfaces are used to connect the host of network cable analyzer and the remote end of network cable analyzer respectively, and N type radio frequency interface is used to connect network analyzer.

[0007] Impedance conversion module includes first balun transformer, second balun transformer and third balun transformer, and first balun transformer is connected with second balun transformer and third balun transformer in turn, and first balun transformer is used to realize impedance conversion, and differential signal and single-ended signal are converted between each other, and second balun transformer and third balun transformer are used to divide three ways output to a way input.

[0008] Specifically, the two RJ45 switching interfaces are first RJ45 switching interface and second RJ45 switching interface, each N type radio frequency interface is connected with the input pin of the first balun transformer of an impedance conversion module, GND ground, one output pin of the first balun transformer is connected with the input pin of the second balun transformer, one output pin of the second balun transformer is connected with the input pin of the third balun transformer, another output pin of the first balun transformer, another output pin of the second balun transformer is connected with two adjacent pins of the first RJ45 switching interface respectively, and two output pins of the third balun transformer are connected with two adjacent pins of the second RJ45 switching interface.

[0009] Specifically, the first balun transformer is 1:2 balun transformer, and the second balun transformer and the third balun transformer are all 1:1 balun transformer.

[0010] Specifically, the first balun transformer is HT-TCM2-33X+, and the second balun transformer and the third balun transformer are all HT-TC1-1-13M+.

[0011] Specifically, the first balun transformer is 1:3 balun transformer, and the second balun transformer and the third balun transformer are all 1:1 balun transformer.

[0012] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0013] The utility model provides a network cable analyzer impedance converter, through with the baron converter as the main component constitutes the impedance converter, promotes from the 250MHz of regulation requirement to 3000MHz on the upper limit of frequency, has realized broadband measurement demand, has covered the measurement range of the majority of novel network cable analyzer on market, network cable analyzer impedance converter includes 4 N type radio frequency interface, is more convenient for with network analyzer standard ware connection, reduces the switching loss. Through setting up two way RJ45 output, can satisfy network cable analyzer to complete different regulation requirement's whole item calibration, including: one is the network cable analyzer without limit of remote end uses network analyzer calibration single mouth calibration, another kind is the network cable analyzer with remote end restriction can use multi -network mouth to complete calibration. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a kind of network cable analyzer impedance converter's principle and internal structure diagram in the utility model embodiment;

[0015] Figure 2 It is the line pair matching appearance interface and external plan view of a kind of network cable analyzer impedance converter of the utility model embodiment;

[0016] Figure 3 It is a kind of application connection schematic diagram of network cable analyzer impedance converter in the utility model embodiment;

[0017] Figure 4 It is another kind of application connection schematic diagram of network cable analyzer impedance converter in the utility model embodiment. DETAILED DESCRIPTION

[0018] The utility model technical scheme will be described in further detail below, obviously the described embodiment is part of the utility model embodiment, instead of all the embodiments, the utility model implementation is not limited to this.Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skill in the art without making creative labor belong to the scope of the utility model protection.

[0019] Embodiment 1:

[0020] According to the requirements of the network cable analyzer calibration specification (JJF 1494-2014), the test object of the network cable analyzer is eight category twisted pair, which is an 8-core shielded line that can support 2000MHz bandwidth and has a transmission rate of up to 40GBase-T. The eight category twisted pair determines the particularity of the cable analyzer parameters and interface, and the interface of the network cable analyzer is an RJ45 type module, which has eight signals, and the characteristic impedance is 100Ω or 150Ω, not 50Ω and 75Ω. In order to solve the impedance matching problem, the utility model is based on the balun converter to make a wideband impedance converter, which raises the upper limit of frequency from 250MHz required by the regulation to 3000MHz. The network line signal of the RJ45 module with 100Ω or 150Ω characteristic impedance can be converted to the interface with 50Ω characteristic impedance, so that the required pair of lines can be selected for testing, and the structure is convenient for the calibration of the network cable analyzer and the daily connection of the network cable analyzer to similar RF equipment testing.

[0021] As shown in Figures 1-4 The utility model discloses a network cable analyzer impedance converter, including two RJ45 transfer interfaces, 4 N type radio frequency interfaces and 4 impedance conversion modules, each N type radio frequency interface is connected with the input end of an impedance conversion module respectively, and the output end of each impedance conversion module is connected with two RJ45 transfer interfaces respectively, two RJ45 transfer interfaces are used for connecting the host of network cable analyzer and the remote end of network cable analyzer respectively, and N type radio frequency interface is used for connecting network analyzer.

[0022] Specifically, the impedance conversion module includes a first balun transformer, a second balun transformer and a third balun transformer, the first balun transformer is connected with the second balun transformer and the third balun transformer in sequence, the first balun transformer is used for realizing impedance conversion and unbalanced end signal and differential balanced signal conversion, and the second balun transformer and the third balun transformer are used for dividing one input into three outputs.

[0023] Preferably, the first balun is a 1:2 balun or a 1:3 balun, and the second balun and the third balun are both 1:1 baluns. In this embodiment, each N-type radio frequency interface is connected with a 1:2 balun or a 1:3 balun for converting an unbalanced signal into a differential balanced signal to match the corresponding wire pair of the twisted pair, and the balun realizes impedance conversion through the transmission line wound on the high-frequency magnetic ring. The ratio of unbalanced impedance to balanced impedance is usually represented by 1:n, for example, the ratio of unbalanced impedance to balanced impedance of the 1:2 balun is 1:2, when the impedance of the N-type interface is 50Ω, i.e. the input port impedance of the balun is 50Ω, then the output port impedance of the 1:2 balun is 100Ω. The ratio of unbalanced impedance to balanced impedance of the 1:1 balun is 1:1, when the input port impedance of the balun is 100Ω, then the output port impedance of the 1:1 balun is also 100Ω. The 1:1 balun is mainly used for shunt output, and the 1:1 balun has one input and two outputs, which has a function similar to a power divider. The input of the second balun is connected with one output of the first balun, and the input of the third balun is connected with one output of the second balun, so that the one output of the first balun can be converted into three outputs through the second balun and the third balun (i.e. one input is divided into three outputs), and the three outputs plus the other output of the first balun, i.e. there are four outputs, which are connected with two adjacent pins of the first RJ45 adapter and the second RJ45 adapter respectively. Similarly, four N-type radio frequency interfaces and four impedance conversion modules can be connected with eight pins of the first RJ45 adapter and the second RJ45 adapter respectively.

[0024] In this embodiment, the first balun is a 1:2 balun, and the model of the 1:2 balun is H2TCM2-33X+, the frequency range is 3000MHz, and the working temperature is -40℃~+85℃. The second balun and the third balun are both 1:1 baluns, and the model of the second balun and the model of the third balun are both HT-TC1-1-13M+, the frequency range is 3000MHz, and the working temperature is -40℃~+85℃.

[0025] Generally, the balun pin includes an input pin, a GND ground and two output pins. Specifically, the two RJ45 adapters include a first RJ45 adapter and a second RJ45 adapter, each of the N-type radio frequency interfaces is connected with the input pin and the GND ground of the first balun of the impedance conversion module, one output pin of the first balun is connected with the input pin of the second balun, the other output pin of the first balun is connected with one pin of the first RJ45 adapter, one output pin of the second balun is connected with the input pin of the third balun, the other output pin of the first balun and the other output pin of the second balun are respectively connected with two adjacent pins of the first RJ45 adapter, and the two output pins of the third balun are connected with two adjacent pins of the second RJ45 adapter. The two adjacent pins correspond to a group of twisted pairs of the network cable, and four impedance conversion modules are respectively connected with eight adjacent pins of the first RJ45 adapter and the second RJ45 adapter, so that eight groups of twisted pairs of the network cable are connected through the RJ45 adapters.

[0026] As shown in Figure 3 The network cable analyzer impedance converter of the utility model can be used in the case that the host and the remote end of the network cable analyzer must be interconnected. The network cable analyzer includes a host and a remote end. The host generates signals and receives signals transmitted by the remote end for data analysis and processing. The remote end responds to the host and transmits signals back to the host. After the host and the remote end are interconnected, the host is equivalent to a remote controller and can control the host and the remote end to complete signal transmission and reception. Therefore, the host and the remote end must be interconnected by using the corresponding impedance converter during calibration. The impedance converter includes a signal transmission function for interconnecting the host and the remote end. In the transmission state, the impedance converter can be understood as a detection device (network analyzer) for detecting signals in the case of interconnecting two network interfaces. If the impedance converter is used in the interconnection state of the host and the remote end, the network analyzer can analyze the modulation and phase of the signal transmission between the host and the remote end. Therefore, the impedance converter can be directly used with a single RJ45 port (the host of the network cable analyzer is directly connected with the network analyzer) or can be used with a double RJ45 port for simultaneous application of the host and the remote end, i.e., the host and the remote end are interconnected, and the network analyzer monitors the transmission link signals. If the existing single-port impedance converter is used to calibrate the network cable analyzer, the host and the remote end cannot be interconnected and the network analyzer cannot receive network signals. During use,

[0027] In the embodiment, four N-type radio frequency interfaces are arranged to facilitate the connection of the network analyzer and the impedance converter. In actual application, the network analyzer can measure the return loss of the four groups of twisted pairs of the auxiliary cable by connecting the four N-type radio frequency interfaces respectively. The impedance converter with the barretter as the main component can improve the bandwidth from the required 250MHz to 3000MHz, and can meet the upper limit of the measurement frequency of the new network cable analyzer on the market. The network analyzer is mainly used for detecting the return loss, phase, amplitude, impedance and other parameters of the entire line. The network analyzer is equipped with a signal source and a signal receiver, and the network cable analyzer is similar, but the network cable analyzer is mainly used for detecting the parameters of the network cable. The network cable analyzer is mainly used for testing the parameters of the network cable, such as return loss, resistance and the like. Figure 4 As shown in the drawing, the network cable analyzer impedance converter of the embodiment of the present application is applied to another connection diagram. The network analyzer is used to calibrate the return loss of the auxiliary cable, and then the network cable analyzer is used to measure the return loss of the device. In fact, they all measure the auxiliary cable (that is, the network cable). The return loss value measured by the network cable analyzer is compared with the return loss value measured by the network analyzer to calculate the error.

[0028] The network cable analyzer impedance converter of the present application is provided. The impedance converter with the barretter as the main component can improve the upper limit of the frequency from the required 250MHz to 3000MHz, realizes the wideband measurement requirement, and covers the measurement range of most new network cable analyzers on the market. The network cable analyzer impedance converter includes four N-type radio frequency interfaces, which is more convenient for connecting with the network analyzer standard device and reduces the switching loss. Two RJ45 output ports are arranged to meet the full project calibration of different regulations required by the network cable analyzer, including: one is a network cable analyzer without remote limit, which is calibrated by a single port using a network analyzer; and the other is a network cable analyzer with remote limit, which can be calibrated by multiple network ports.

[0029] The above embodiment is the preferred embodiment of the present application, but the embodiment of the present application is not limited to the above embodiment. Any change, modification, substitution, combination, simplification, which does not deviate from the spirit and principle of the present application, should be an equivalent replacement method, and is included in the protection scope of the present application.

Claims

1. A network cable analyzer impedance converter, comprising: The application relates to a network cable analyzer, which comprises the following: two RJ45 conversion interfaces, four N-type radio frequency interfaces and four impedance conversion modules, each N-type radio frequency interface is connected with the input end of one impedance conversion module, and the output end of each impedance conversion module is connected with two RJ45 conversion interfaces; the two RJ45 conversion interfaces are used for connecting the host of the network cable analyzer and the remote end of the network cable analyzer respectively, and the N-type radio frequency interfaces are used for connecting a network analyzer; the impedance conversion module comprises a first balun transformer, a second balun transformer and a third balun transformer, the first balun transformer is connected with the second balun transformer and the third balun transformer in sequence, the first balun transformer is used for realizing impedance conversion and conversion between unbalanced end signals and differential balanced signals, and the second balun transformer and the third balun transformer are used for dividing one input into three outputs.

2. A network cable analyzer impedance converter according to claim 1, wherein, The two RJ45 conversion interfaces are a first RJ45 conversion interface and a second RJ45 conversion interface, each N-type radio frequency interface is connected with the input pin and the GND ground of the first balun transformer of one impedance conversion module, one output pin of the first balun transformer is connected with the input pin of the second balun transformer, one output pin of the second balun transformer is connected with the input pin of the third balun transformer, the other output pin of the first balun transformer and the other output pin of the second balun transformer are connected with two adjacent pins of the first RJ45 conversion interface respectively, and two output pins of the third balun transformer are connected with two adjacent pins of the second RJ45 conversion interface.

3. The network cable analyzer impedance converter of claim 1, wherein, The first balun transformer is a 1:2 balun transformer, and the second balun transformer and the third balun transformer are both 1:1 balun transformers.

4. A network cable analyzer impedance converter according to claim 3, wherein, The model of the first balun transformer is HT-TCM2-33X+, and the models of the second balun transformer and the third balun transformer are both HT-TC1-1-13M+.

5. The network cable analyzer impedance converter of claim 1, wherein, The first balun transformer is a 1:3 balun transformer, and the second balun transformer and the third balun transformer are both 1:1 balun transformers.

Images