Title :
A 2-V 2-GHz Si-bipolar direct-conversion quadrature modulator
Author :
Tsukahara, Tsuneo ; Ishikawa, Masayuki ; Muraguchi, Masahiro
Author_Institution :
High-Speed Integrated Cicuits Lab., NTT LSI Labs., Kanagawa, Japan
fDate :
2/1/1996 12:00:00 AM
Abstract :
A 2-GHz Si-bipolar direct-conversion quadrature modulator with a wide bandwidth is described. It operates at a low supply-voltage of 2 V and features a “current-folded” double-balanced mixer with a two-stacked-transistor configuration, and a tunable RC/CR 90° phase shifter that reduces the amplitude imbalance and the phase error over a wide bandwidth (0.8 to 2 GHz). The modulator is implemented using 18-GHz Si-bipolar technology and dissipates only 68 mW at 2 V. The image ratio at 2 GHz is about -37 dBc, corresponding to a phase error of 1.6°. Moreover, both second-order and third-order products, and local signal leakage are less than -40 dBc
Keywords :
UHF integrated circuits; bipolar analogue integrated circuits; elemental semiconductors; modulators; quadrature phase shift keying; silicon; 0.8 to 2 GHz; 1.2 GHz; 18 GHz; 2 V; 68 mW; Si; Si bipolar technology; bipolar UHF IC; current-folded double-balanced mixer; direct-conversion quadrature modulator; low supply-voltage operation; phase error; tunable RC/CR 90° phase shifter; two-stacked-transistor configuration; wideband operation; Bandwidth; Frequency modulation; Large scale integration; Monolithic integrated circuits; Phase modulation; Phase shifters; Radio frequency; Radiofrequency integrated circuits; Tunable circuits and devices; Voltage;
Journal_Title :
Solid-State Circuits, IEEE Journal of
