A wide-band direct conversion receiver with on-chip A/D converters

In wireless communications, the receiver architectures, which have on-chip channel selection filters like direct conversion or low-IF, are preferred to increase the integration level. Combining digital signal processing on the same chip with analog circuits would be desirable in the miniaturization. Some recent papers present highly integrated tranceivers with mixed-mode or digital circuits on the same chip. However, only little discussion or experimental results have been given on the potential problems related to the system. This paper focuses on the design aspects of the single-chip direct conversion receivers, and gives experimental results of the BiCMOS prototype. The chip includes RF front-end, analog baseband signal processing and 6-bit A/D converters on the same die. It operates in the third generation wideband CDMA wireless system at 2 GHz.