Low power 2.4 GHz quadrature generation for body area network applications

This paper presents two implementations of low-power quadrature generation for the new Bluetooth low energy standard in the 2.4 GHz ISM band. Both implementation have been designed in a 90 nm CMOS technology for a 1 V supply voltage and post-layout simulation results are presented. The first implementation is a quadrature voltage controlled oscillator (QVCO) with 180 μW power consumption and a phase noise of -112.7 dBc/Hz @1MHz. It employs a new technique to reduce the influence of magnetic coupling between the two spiral inductors. The second implementation employs a VCO running at twice the frequency with a subsequent divide-by-2 stage. Its total power consumption is 320 μW and the phase noise at the quadrature outputs is -115.7 dBc/Hz @1MHz.