A 28 GHz Complementary QVCO Using Current Re-used and Parallel Coupling Technique

In this paper, we propose a complementary quadrature voltage-controlled oscillator ($\boldsymbol{QVCO}$) at 28 GHz. This work combines the current re-used and parallel coupling technique in $\boldsymbol{QVCO.}$ We also use the complementary device to implement the current re-used technique to save dc power. To avoid stacking structure, the quadrature-phase is achieved by the parallel coupling technique. The measured tuning range is 5.16 % and the measured lowest phase noise is -103.4 dBc/Hz at 1 MHz offset from carrier frequency at 28.36 GHz. The measured phase error is less than $\pm 3^{\circ}$ across all tuning frequencies. The core dc power consumption is only 21 mW for 1.8 V supply voltage. To our best knowledge, this $\boldsymbol{QVCO}$ has the lowest phase error and an accurate quadrature phase.