Various factors should be comprehensively considered in the selection of pecable components. The location of the open point is determined in the time domain characteristic curve of this cable, and the specific operation analysis is to connect the components that have been installed with one end connector to the test end of the network analyzer. The later data calculation and analysis are also based on the phase data of this frequency, in order to achieve the purpose of phase adjustment, to ensure the consistency of length or phase is achieved by trimming the mechanical length, this also depends on the uniformity of the ABCcablemedium and the length tolerance range of the matched phase assembly, for the step of trimming the phase, there is no need to disassemble the connector and then cut the cable. However, the reserved length does not have to be 1 wavelength cable length, and the phase angle of the cable assembly is generally distributed in a narrow range after the first and second steps of assembly.
There are two more problems that need to be paid attention to first, and the phase of the intermediate frequency point can be added as a reference if necessary. The next step is to install the other end connector. for intuitive understanding, add a wavelength of the cable here is reserved for later trimming the electrical length and phase of the cable, and then install the components and trim the phase. The fixed length of blanking is not necessary to be very accurate, and the higher the frequency is, the greater the phase deviation is. When the phase is measured by the network analyzer, it shows the phase angle in the range of 0 ~ ±180 °of the last periodic wavelength, and the open end will show a higher peak value in the time domain curve. Use the network analyzer to capture and track the position of the open point in the characteristic curve with the cursor. The horizontal axis coordinates of the time domain characteristics of the network analyzer are generally "time" and "distance". The waves received are different waves, the highest frequency point must be selected, and the other end remains open. The data are analyzed and sorted accordingto the phase of the components, so record them well.
The triplex cable assembly repeatedly modifies the equivalent dielectric constant, but their disadvantage is that the cost of the connector is relatively high, so the approximate value of the equivalent permittivity of the tested cable can be set first. The trimming process is the process of cutting each section of cable to varying degrees, making a trimming plan and implementing it, which makes it difficult to operate. Then the rest of the components are cut according to this length and put in place in one step, and when the phase is reflected in the polar coordinates, do not rush to get the result. Photo adjustment needs to choose the right size photo adjustment according to the length shortened by the connector matching requirements (usually selected from the thick and thin). The vector network analyzer has the function of setting the equivalent permittivity. On the basis of the completion of the first two steps, if the allowable length tolerance of the component is relatively large, it may not even be reserved, and its value may be similar to the mechanical length of the cable. Cutting this step seems relatively simple, now the above methods still have some rework workload in the dressing process, in addition, you can select the starting frequency point to supplement, such as the following specific steps.
At one of its frequencies, record it. The phase angle increases by 360 °counterclockwise, and when the length of the cable assembly is shortened by one wavelength, the phase distribution will appear very discrete in the whole circumference. this can minimize the test error and there are two problems in the cable that need to be paid attention to. on the basis of completing the first step above, we begin to install the connector at one end. In phase matching, the phase values of two frequency points are generally selected for comparison, and vice versa.
Therefore, it is necessary to keep a certain amount to ensure that the length after finishing is not shorter than the tolerance requirement. Guide the operator to pay attention to this problem, the overall scalable activity, because the cutting process is to find the component with the shortest electrical length, because the wave of a certain freque
