| 摘要 |
Improved CATV converter (10) that incorporates an intermediate frequency filter and amplifier unit (16) that includes first and second tunable circuits (31, 32). Each tunable circuit (31, 32) has a fixed capacitive element (33, 34) and a variable inductance means (37, 38) for tuning the tunable circuit (31). The first and second tuned circuits (31, 32) are transmissively coupled to one another through a slit (40) in a shield (39) which otherwise shields one tunable circuit (31) from another. The intermediate frequency filter and amplifier unit (16) also includes an FET (50) for amplifying a narrow band intermediate frequency signal and a third tunable circuit (71) comprising the output capacitance of the FET (50) and a variable inductance means (74) for tuning the third tunable circuit (71). |
