Second and Third Order Distortion Compensation in Bipolar Gilbert Mixer

G. BARRAZA; M. BRUNO; J. E. COUSSEAU

Oro Verde, Entre Rios

Congreso; XIV Reunión de Trabajo en Procesamiento de la Información y Control; 2011

Universidad Nacional de Entre Rios

This paper presents a comparison on second and third order nonlinearity effects in Gilbertmixer and its variants, which are present in the majority wideband receivers. The implementations are made using bipolar transistors and are based on CMOS existingdesigns. The reason for using bipolar transistors is due to a larger transconductance and lower noise they have compared with MOS devices. We investigate about distortion sources and its effects on reception, and also the new design trends developed to compensate them.Simulations results show that Gilbert mixer with a crossconnected differential input pair has fewer output harmonics if compared with other designs. However, it presents a lower dynamic range. Also, parallel transistors input design shows fewer amplitude in harmoniccomponents and intermodulation compared with the resistive and inductive emitter degeneration topology. This last topology retains the same advantages anddisadvantages to their similar CMOS equivalent.