A UWB receiver with modified CS‐CG LNTA: Noise and nonlinearity analysis

Abstract

SummaryA modified common source‐common gate (CS‐CG) low‐noise transconductance amplifier (LNTA) with an improved noise figure (NF), operational bandwidth, and power consumption are analyzed in this paper. The common source (CS) stage of the modified LNTA is utilized for noise cancellation and transconductance enhancement of the common gate (CG) transistor. Using these, NF, bandwidth, and power consumption are improved without using extra active elements. Noise analyses show the modified CS‐CG LNTA has lower NF than conventional CS‐CG LNTA. The linearity of the modified CS‐CG LNTA is calculated by Taylor series expression. Besides, a design procedure is proposed based on the obtained equations for linearity and NF. Finally, an ultra‐wideband (UWB) surface acoustic wave (SAW‐less) direct‐conversion receiver is designed in 65 nm complementary metal‐oxide‐semiconductor (CMOS) technology. NF and third‐order intercept point (IIP3) of the designed receiver are simulated as 5 dB and −2 dBm, respectively. The receiver consumes 18.4 mA from a 1.8 V supply voltage.