| 摘要 |
<p>An automatic impedance matching front end interface circuit includes a processor (56) and a plurality of variable resistors (16, 18, 40, 46, 48, 50), the resistances of which are adjustable by the processor (56) to achieve impedance matching such that the upstream and downstream signals flow in desired directions. A method of adjusting the resistances of the variable resistors (16, 18, 40, 46, 48, 50) includes measuring two voltages at different locations along a downstream transmission line, obtaining a measured voltage ratio, comparing the measured ratio to an optimal ratio, and adjusting the resistances of the variable resistors (16, 18, 40, 46, 48, 50) to cause the measured ratio to approach the optimal ratio.</p> |
