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.