A 2.4 GHz High Linearity Subthreshold Current Mode Folded CMOS Mixer

Abstract

In this paper, a new CMOS active mixer using a parallel-folded topology which can operate at sub-1 V supply voltage is proposed. Such current mode mixer requires less voltage headroom with good linearization. In the proposed circuit, LC resonators were adapted to replace a commonly used current source, and current mirrors replace the common load resistances to export currents, the core of mixer works in a subthreshold region. This paper analyzes the performance of the high-linearity current mode mixer, comparing with other current mode mixer; this circuit demonstrates competitive performance with a lower supply voltage, higher linearity. A layout was designed and simulated in the standard chartered 0.18 μm RF CMOS process with Spectre in Cadence Design Systems. Simulation results show a satisfied mixer performance at 2.4 GHz. The simulated 11P3 of 13.48 dBm, with a power gain of -0.21 dB is obtained. A low dissipation power of 5.3 mW at 1 V supply voltage is also achieved.