Patent ID: 6674337
Filing Date: 2004-01-06
Classification: H03F

Abstract:
A concurrent dual band LNA, having an input and an output that operates simultaneously at 2.45 GHz and 5.25 GHz center frequency bands, comprising:(a) a CMOS transistor disposed on a semiconductor substrate and having a gate, g, a drain, d, a source, s, and a characteristic transconductance, gm, (b) an input impedance network, Zin, that simultaneously and independently matches the frequency-dependent input impedance of the transistor to a 50 ohm characteristic impedance at center frequencies of 2.45 GHz and 5.25 GHz, and defined by the equations: Zin=Zg+Zgs+Z's+gmZ'sZgs,=50 &OHgr; and Zg+Zgs+Z's=0 wherein:(i) Zg is an input parallel resonator having a capacitor in parallel with an inductor, disposed between the LNA input and gate and with a wire bonded to the gate, (ii) Zgs is the impedance between the gate and source, and (iii) Z's is an inductor disposed between the source and AC ground; and (c) an output load network, ZL, that simultaneously provides a voltage gain, Av, to an input signal at the LNA input at the 2.45 GHz and 5.25 GHz center frequencies, wherein the output load network, ZL, is a series LC branch circuit, in parallel with a parallel LC tank circuit.