摘要 |
A tunable coupling network for a frequency multiplier stage providing a passband for a desired harmonic of a fundamental frequency and rejection notches for undesired harmonic frequencies. The passband of the network can be tuned by changing the value of at least one circuit element to track the desired harmonic of the fundamental frequency over a range of fundamental frequencies. In so doing, the rejection notches also move so that they maintain fixed ratios with respect to the passband frequency as the passband moves. In one embodiment the network comprises first and second tunable circuits each including a variable reactive element. The first resonant circuit includes a variable capacitor and two fixed inductors. The second resonant circuit includes a variable inductor and two fixed capacitors. The two resonant circuits are coupled by an interstage coupling capacitor.
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