Design and Simulation of a Variable Gain Down Conversion Mixer for 2.4 GHz ISM Band Applications

Abstract

In recent years, the importance of wireless sensor networks, maritime surveillance systems and autonomous marine systems has grown significantly, leading to the need for low power and high performance wireless receiver circuits in the 2.4 GHz ISM band. A low power down conversion mixer using current-reuse variable gain amplification technique is presented in this paper for maritime wireless communication. The proposed architecture is based on the concept of incorporating a variable gain amplifier inside the current-bleeding path of the mixer that allows adaptive gain control without consuming a significant amount of current through the path of the mixer. Simulated result shows a maximum gain for conversion of 17.8 dB and a VGR (Variable Gain Range) of about +44 dB and a minimum double-sideband noise figure of 7 dB. With just 5.6 mW of supply 1.8 V, the circuit provides an input third-order intercept point (IIP3) of −14.4 dBm. The results have shown that the proposed receiver front-end is suitable for marine IoT devices, shipboard wireless monitoring networks, and other  maritime communication systems exhibiting low power consumption and reliable reception under different channel conditions.