Dual-band CMOS front-end with two gain modes

摘要

A multi-band low noise amplifier (LNA) 105 includes an input stage having at least two inputs, a first input (103) coupled to a first input transistor for receiving signals in a first frequency band and a second input (104) coupled to a second input transistor for receiving signals in a second frequency band. The second frequency band spaced apart from the first frequency band. A bias network (218) having a band select input is coupled to the first and second input transistor, wherein a signal level applied to the band select input turns on one of the input transistors and turns off the other input transistors. The LNA (105) operates in the first frequency band when the first input transistor is on and the second frequency band when the second input transistor is on. A switched resonator (216) having a control input is provided, wherein application of a control signal to the control input tunes a resonant frequency of the LNA, and provides gain select, for operation in either the first or second frequency band.