Systems and methods for impedance shifting between filters and amplifiers

Abstract

Systems and methods for impedance shifting between filters and amplifiers are disclosed. In one aspect, an active inductor that might otherwise be placed between a filter and a low noise amplifier (LNA) may be replaced with a passive impedance-boosting circuit. The impedance-boosting circuit may, for example, be a passive voltage gain circuit and may, by way of further example, be implemented with a coupled resonator filter (CRF) structure. Using such a passive voltage gain structure in receive circuits where the input noise is dominated by a noise voltage component means that any passive voltage gain in front of the active amplifier will result in a reduction of the overall receive path noise figure and may, potentially, save space that would otherwise be devoted to large inductor circuits.

Dependencies are inferred from the claim text.