Patent ID: 6798288
Filing Date: 2004-09-28
Classification: H03F

Abstract:
A bandpass amplifier for use in a communication system having a transmit band and a receive band associated therewith, comprising:a frequency selective network for noise shaping an input signal, the frequency selective network comprising first filtering circuitry for selectively passing the transmit band, and second filtering circuitry for selectively passing the receive band, the first and second filtering circuitry being configured to effect suppression of energy associated with the transmit band in the receive band; an analog-to-digital converter coupled to the frequency selective network; a switching device coupled to the analog-to-digital converter for producing an output signal; and a feedback path for feeding back the output signal to the frequency selective network to facilitate the noise shaping, wherein the first filtering circuitry comprises at least one transmit band resonator operable to resonate at the transmit band, and the second filtering circuitry comprises at least one receive band resonator operable to resonate at the receive band, wherein at least one of the transmit band and receive band resonators comprises a transconductive element, an inductive element, and a capacitive element, and wherein the capacitive element comprises a bank of capacitors for tuning the corresponding resonator.