Power Consumption Of Low-noise Amplifier Research Articles

A high linearity and high gain Folded Cascode LNA for narrowband receiver applications

Folded Cascode (FC) Low Noise Amplifier (LNA) is preferred for low voltage and low power RF applications. A FC LNA with gm-boosting technique is reported in the literature. Under low voltage operation, linearity of the LNAs is degraded due to transconductance and drain conductance nonlinearities. To improve the linearity of the LNAs, several techniques namely Harmonic Termination Network, Derivative Superposition, Modified Derivative Superposition (MDS) techniques are reported in the literature. In this paper to achieve high linearity for the gm-boosting FC LNA, MDS technique is incorporated at the Common Source (CS) stage and is proposed. In order to evaluate the efficacy of this approach, the proposed LNA is designed and implemented in UMC 0.18µm MMRF CMOS process for 2.44GHz. From the simulation results, it is found that the proposed LNA achieves a gain (S21) of 14.6dB, Noise Figure (NF) of 2.9dB, Input matching (S11) of −15dB and third order Input Intercept Point (IIP3) of +4.19dBm. The power consumption of LNA is 3.8mW for a supply voltage of 0.6V. The proposed LNA has a higher Figure of Merit (FoM) than that of other Cascode LNAs reported in the literature.

Cooling a low noise amplifier with a micromachined cryogenic cooler

The sensitivity of antenna systems increases with increasing active area, but decreases at higher noise figure of the low-noise amplifier (LNA). Cooling the LNA locally results in significant improvement in the gain and in lowering the noise figure of the LNA. Micromachined Joule-Thomson (JT) coolers can provide a cryogenic environment to the LNA. They are attractive because they have no cold moving parts and can be scaled down to match the size and the power consumption of LNAs. The performance of a LNA mounted on a JT microcooler with dimensions of 60.0 × 9.5 × 0.72 mm(3) is reported in this paper. The microcooler is operated with nitrogen gas and the cold-end temperature is controlled at 115 K. The measured net cooling power of the microcooler is about 43 mW when the LNA is not operating. The power dissipation of the LNA is 26 mW, with a supply voltage of 2 V. At room temperature the noise figure of the LNA is 0.83 dB and the gain lies between 17.9 and 13.1 dB, in the frequency range of 0.65 and 1.05 GHz. Upon cooling to 115 K, the noise figure drops to 0.50 dB and the increase in gain varies in the range of 0.6-1.5 dB.