Patent ID: 7683742
Filing Date: 2010-03-23
Classification: H03H,H03J

Abstract:
1. An electronic circuit, comprising: an acoustic resonator of BAW or SAW type, said resonator having a series resonant frequency and a parallel resonant frequency; and an active circuit which is coupled in parallel to said acoustic resonator, said active circuit having a negative capacity to act on the parallel resonant frequency of said resonator, the active circuit comprising a first input terminal and a second input terminal and further comprising: a first branch coupled between a first reference voltage and a second voltage reference, said first branch having, in series, a first biasing resistor, a first diode, a collector-emitter circuit of a first bipolar transistor, and a first current source; a second branch coupled between said first reference voltage and said second reference voltage, said second branch having, in series, a second biasing resistor, a second diode, a collector-emitter circuit of a second bipolar transistor, and a second current source, said first transistor having a base terminal which is coupled to a collector terminal of said second transistor and to said second input terminal, and said second transistor having a base terminal which is coupled to a collector terminal of said first transistor and to said first input terminal; a capacitor coupled between an emitter terminal of said first bipolar transistor and an emitter terminal of said second bipolar transistor; and a linearization resistor which is coupled in parallel between the emitter terminals of said first and said second bipolar transistors.