Low noise amplifier with embedded filter and related wireless communication unit

摘要

In one embodiment, a WCDMA FDD system includes an embedded filter that provides a complex load to transistors in a low noise amplifier. The complex load can be constructed using passive and/or active devices and creates an arbitrary transfer function that supports selective Q-enhancement of poles or zeros. One particular implementation of the embedded filter is in the form of an LC tank circuit. The LC tank circuit is operably coupled to the output of the low noise amplifier and creates a transfer function whose poles and zeros can be selected to reject transmitter leakage in the WCDMA system, while maintain a desirable gain at the frequency of operation.

主权项

1. A circuit system comprising:
a low noise amplifier having an input and an output, the input being configured to be connected to a receiver input signal; and a complex load driven by the low noise amplifier, wherein the complex load provides an arbitrary transfer function with multiple poles and zeros, wherein the complex load is provided by two LC tank circuits having a transfer function that is configured to reject unwanted signals and maintain the gain of the amplifier, wherein at least one of the LC tank circuits employs on-chip spiral inductors.