State of the Art for Differential Circuits in Wireless Transceivers: A New Wideband Active Balun in SiGe BiCMOS Technology

Authors : Balwant GODARA, Alain FABRE

Pages : 355-386

View : 15 | Download : 10

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The aim of this paper is 3-fold: firstly, to provide a comprehensive overview of the use of differential circuits for analogue signal processing in wireless transceivers; secondly, to describe, in detail, single-ended signal to differential conversion, and the corresponding theory of such devices, their characterisation, various methods of implementation, and comparative analyses of their performance; lastly, to propose a new transistor-based solution for wideband baluns. This novel solution is based on the current conveyor and has been modelled using the transistor parameters of a 0.35 m m SiGe BiCMOS technology. The salient features of the new implementation are: insert ignore into journalissuearticles values(a); stable 50-W input port impedance and easily controllable output impedance insert ignore into journalissuearticles values(50 W/75 W/100 W);; insert ignore into journalissuearticles values(b); stable matching between the differential output ports, within 1 dB insert ignore into journalissuearticles values(3 dB); amplitude and 10° insert ignore into journalissuearticles values(20°); phase balance up to 2 GHz insert ignore into journalissuearticles values(3 GHz);; insert ignore into journalissuearticles values(c); good signal quality with output signal harmonic distortion lower than 1% for peak-to-peak input signals up to 50 mV; insert ignore into journalissuearticles values(d); excellent S-parameter performance insert ignore into journalissuearticles values(0-3 GHz); with return losses lower than --10 dB, reverse signal rejection better than 20 dB, more than 25 dB isolation between the output ports, and 42 dB common-mode rejection; and insert ignore into journalissuearticles values(d); stable performance over a 100 °C operating temperature range. This performance advances the state of the art for single-ended to differential conversion circuits insert ignore into journalissuearticles values(evinced upon detailed comparisons to existent baluns);.
Keywords : Active Balun, Current Conveyors, Differential Analogue Circuits, S Parameters, SiGe BiCMOS