Fully-integrated DECT/Bluetooth multi-band LNA in 0.18µm CMOS

The design of a multi-band low noise amplifier (LNA) is the first obstacle towards the design of a multi-standard receiver. In this paper, an approach for the design of a multi-band LNA for DECT and Bluetooth is presented. The formula for a minimal noise factor of a LNA, that takes into account the finite quality factor of the inductors is derived and the full design procedure that facilitates the design of a fully integrated LNA is given. The main advantages of the presented multi-band LNA are: high level of integration, reduced chip area by using only one integrated inductor, while the other is implemented as a bond-wire, input matching at two frequencies while having low noise figure, moderate voltage gain and good linearity. In DECT mode the simulated LNA performance is: NF = 2.2 dB, gain = 17 dB, IIP3 = 0.5 dBm, with a current of 8 mA, while in Bluetooth mode the LNA achieves: NF = 2.3 dB, gain = 15 dB, IIP3 = 3 dBm, with a current of only 4 mA.