High-Q LNA With a VCO for Small Calibration Frequency Errors

Abstract

A high-quality (Q) low-noise amplifier (LNA) combined with a voltage-controlled oscillator (VCO) is presented for small frequency errors in self-calibration. The proposed new double capacitive-cross-coupled structure controls negative impedance and thus, changes the working mode between the LNA and VCO with a small variation of parasitic capacitance, which results in a small calibration frequency error. High-Q and low-noise performances were theoretically analyzed and confirmed by simulation and measurement. The measured LNA operated from 2.2 to 2.44 GHz with a Q-factor of 34 while the frequency offset was less than 0.9%. A power gain of 27 dB, noise figure of 2.1 dB, and input third-order intercept point (IIP3) of -17 dBm were obtained while the power dissipations of the LNA and VCO modes were 10.2 and 4.7 mW from a 1.5-V supply, respectively.