| 摘要 |
A tunable impedance network ( 20, 30, 40, 50) comprising at least one variable impedance bank (24, 34) comprising a plurality of digitally controlled unit cells (23, 33) each connected from at least a first end to a routing wire (21, 31). The tunable impedance network is provided with selection means (40) arranged for selecting based on the desired impedance the corresponding digital control signal to be supplied to the bank (24, 34) to switch-on a corresponding combination of said unit cells (23, 33). Between each pair of unit cells (23, 33) in the bank (24, 34) a routing wire section (22, 32) is provided having a routing impedance. Each of the predetermined control signals is provided for switching-on a combination of unit cells (23, 33) in such a way that the routing impedance of the routing wire section (22, 32) is exploited to fine-tune the actual impedance generated by the variable impedance bank (24, 34). |
