A low-power high-frequency sinusoidalquadrature oscillator is presented through the use of two allpasscurrent mirror (CM)-based filters, a 1st-order CM lowpassfilter and a CM bilinear transfer function. The bilineartransfer function is described in terms of a negative resistance(RN = -RL) where RL is a resistor load of a current mirror. Thetechnique is relatively simple based on (i) inherent timeconstants of current mirrors, i.e. the internal capacitances andthe transconductance of a diode-connected NMOS, (ii) a simplenegative resistance RN formed by a resistor load RL of acurrent mirror. Neither external capacitances nor inductancesare required. As a particular example, a 1.01-GHz, 0.6-mW, 2-V CMOS all-pass-filter-based all-current-mirror sinusoidalquadrature oscillator is demonstrated in this paper. Theoscillation frequency (f0) is 1.01 GHz and is current-tunableover a range of 400 MHz or 40 %. The power consumption isat approximately 0.6 mW. The amplitude matching and thequadrature phase matching are better than 0.05 dB and 0.15°,respectively. Total harmonic distortions (THD) are less than0.5 %. At 2 MHz offset from the 1.01 GHz, the carrier to noiseratio (CNR) is 83.01 dBc/Hz whilst the figure of merit called anormalized carrier-to-noise ratio (CNRnorm) is 139.29 dBc/Hz.The ratio of the oscillation frequency (f0) to the unity-gainfrequency (fT) of a transistor is 0.134.