Study of 2.4GHz CMOS LNA & mixer circuit for low power WPAN(IEEE 802.15.4) application

Abstract

To implement low power communication system, not only each block``s power efficiency but also proper architecture is important. So proper RF system architecture and specification for RF and analog-baseband is studied. LNA and Mixer circuit for low power WPAN (IEEE 802.15.4) which is designed for low IF topology is fabricated and measured. To implement low power LNA and Mixer circuit switching operation is adopted. Total power consumption is 1.5mA at 1.8volt Vdd at 26dB voltage gain. Also Multiple Gated Transistor with Cascode configuration CMOS RF amplifier is proposed and measured. With proper combination of input transistors in parallel, $g_m``$ is effectively reduced, and with further improvement in nonlinearity due to combination of ,$u_m``$ and harmonic feedback by cascode configuration, we obtained IP3 improvement as large as 10dB at similar power consumption and gain.