Research Activities > Programs >
Oversampling and Coarse Quantization for Signals
CSIC Building (#406),
Seminar Room 4122.
Continuous-Time Modulators for RF Applications
Ultra-High Speed Circuits Deptartment at HRL Laboratories LLC.
We present the status and challenges of
continuous-time ΣΔ modulators for RF applications.
The paper includes operation principals,
state-of-the-arts, and future prospects of this
essential ADC technology for high-resolution and
high dynamic range. Improvements in semiconductor
technology and oversampled ADC converters are
provide the capability to move the digitization
process forward in the signal path of RF system and
perform more receiver functions in the digital
domain. Continuous time design approaches for
oversampled ADC can provide higher frequency
operation over the conventional discrete time design
approaches. Tunable bandpass loop filter
implementations provide the opportunity to digitize
at IF or RF. We will discuss circuit design
techniques for active GM-C bandpass loop filter for
high dynamic range applications. Multi-bit
approaches are need for wider bandwidth
applications. Multi-bit noise shaped oversampled
converter require techniques for feedback DAC error
correction. We will show demonstrated techniques for
bandpass mismatch shaping of DAC errors to reduce
DAC quantization noise.