PROJECT TITLE :

An Incremental-Charge-Based Digital Transmitter With Built-in Filtering

ABSTRACT:

A totally integrated transmitter design operating in the charge-domain with incremental signaling is presented. The architecture provides improved out-of-band noise performance, because of an intrinsic low-pass noise filtering capability, reduced quantization noise scaled by capacitance ratios, and sinc 2 alias attenuation because of a quasi-linear reconstruction interpolation. With a respective unit and baseband capacitances of 2 fF and 45 pF, the architecture attains a possible 14 bit equivalent quantization noise with a 1024 unit capacitance array. Using four ten bit charge-primarily based DACs (QDACs) at 128 MS/s sampling rate, it achieves $-$fifteen5 dBc/Hz at 45 MHz offset from a 1 GHz modulated carrier. The incremental-charge-based mostly operation conjointly leads to an improved potency at back-off conditions. For an average output power of one dBm (twenty MHz BW), total power consumption is forty one.3 mW, of which solely 0.5 mW corresponds to the system charge intake. The prototype is implemented employing a 28 nm 0.nine V CMOS technology, with a core space of zero.25 mm 2 . With a reduced sampling frequency and variety of bits, power and area consumption are among the best and can directly profit from future technology scaling .