| abstract |
A tuning circuit for adjusting an oscillation frequency of an oscillator circuit. The tuning circuit comprises a film bulk acoustic wave resonator (FBAR) having a series resonance frequency and a parallel resonance frequency, and an inductor coupled in series or parallel with the film bulk acoustic wave resonator. The series connection of the inductor and FBAR decreases the series resonance frequency. The parallel connection of the inductor and the FBAR increases the parallel resonance frequency. The tuning circuit further comprises a varactor coupled in series or parallel with the inductor and the FBAR combination. The varactor tunes the oscillation frequency over the increased tuning range. |