| 摘要 |
<p>@ A tuning arrangement comprising a tunable RF-circuit (2), a mixer stage (4) coupled thereto, an oscillator circuit (6) having a tunable resonant circuit and a for both circuits common tuning to mutually different resonant frequencies, of which at least the circuit having the higher resonant frequency comprises a parallel circuit of on the one hand a circuit inductance (L4) and on the other hand a series arrangement of a tuning capacitor (C2) and a padding capacitor (Cp). For an acceptable tracking between the resonant frequencies of the two circuits, more specifically in the lower frequency portion of the tuning range, the padding capacitor is shunted by a coil (LC) which considerably reduces the capacitance of the padding capacitor at least in said portion of the tuning range.</p> |
