- 真可
-
According to the structure of the definition, I return loss using computer technology inspection center program-controlled formed structure return loss measurement system. Below are the same cable return loss and the structure of the return loss measurement result in loss of echo, the worst value for 21.92 dB, and structure of the worst value for return loss 24.11 dB, two worst appearing in the same frequency.
By definition can see: return loss reflects the input impedance of the cable with measuring system impedance deviation between the, it not only embodies the inhomogeneity of cable structure and reflects the cable impedance measurement system impedance matching degree of deviation (or), And structure of cable return loss only reflect their impedance input impedance and cable, so, the average deviation structure reflects the return loss only cable itself the inhomogeneity of the structure. Although return loss and the structure of two kinds of indexes return loss can reflect the quality of cable, but return loss only reflect cable structure, and the structure of uneven with cable impedance deviation system impedance. Unless the cable impedance average very close and system impedance, otherwise structure return loss is better than always return loss.
希望你大致还满意。O(∩_∩)O~
- 余辉
-
Based on the definition of structural return loss, our testing centre set up a structural return loss measurement system with the computer program control technology . The following is return loss and structural return loss measurements diagram for the same cable. In the diagram, the worst return loss value is 21.92dB, while the worst structural return loss value is 24.11dB. Both worst values occurred at the same frequency.
Can be seen from the definition: Return loss reflects the deviation between cable input impedance and measurement system impedance. It reflects the heterogeneity of the cable structure and the deviation (or the matching level) of cable input impedance and measurement system impedance; and structural return loss reflects only the deviation of cable input impedance and cable average impedance. Therefore, structural return loss only reflects the heterogeneity of the cable structure. Both the return loss and structural return loss can reflect good or bad quality of cable. However, structural return loss reflects only the heterogeneity of the cable structure, irrelevant to the deviation of cable impedance and system impedance. Unless the average of cable characteristic impedance is very close to the system impedance, structural return loss will be always better than return loss.
- LuckySXyd
-
Based on the definition of SRL the present Inspection Test Center sets up a SRL measurement system based on computer program control technique. The following Fig. shows the measurement results of the RL and SRL from a same cable, where the worst value for RL is 21.92 dB, while the worst value of SRL is 24.11 dB, both the worst values occur at the same frequency point.
From the above mentioned definitions it can be seen that the RL reflects the deviation of cable"s input impedance from the measurement system"s impedance, it not only embodies the structural nonuniformity of the cable, but also embodies the deviation (or matching degree) of cable impedance from the measurement system"s impedance; while SRL only reflects the deviation of cable"s input impedance from the averaging value of the impedances of the cable itself, so what SRL reflects is the structural nonuniformity of the cable itself only. Although both indicators, RL and SRL, can reflect the quality of the cable, STL only reflects the structural nonuniformity regardless of how the cable impedance deviating from the system"s impedance. Unless the averaging value of the cable"s characteristic impedance is very close to the system"s impedance or SRL always is better than RL.