Complex bandpass &amp;#x0394;&amp;#x03A3;AD modulator with noise-coupled image rejection

San, Hao; Kobayashi, Haruo

doi:10.1109/mwscas.2009.5236080

Cited by 3 publications

(1 citation statement)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another way is to use the noise coupling technique. This technique is used to increase the order of the lowpass [11]- [18] and co mplex bandpass modulators [19], [20]. In this technique, processing of the quantization noise and applying it to the quantizer input can lead to increase order of the noise shaping.…”

Section: Introductionmentioning

confidence: 99%

Filter Loop Reduction in DT BP Sigma-Delta Modulator Assisted by Noise Coupling Technique

Gholami¹,

Ardeshir²,

Naimi³

2014

IJISA

View full text Add to dashboard Cite

In bandpass modulators, a 2N-order loop filter can lead to an N-order noise shaping in the band of interest. This caused a bandpass modulator with more complex structure than a lowpass modulator and increased the power consumption and area of the modulator. In this paper, we proposed a discrete-time bandpass modulator using the noise-coupling technique that only needs to a second-order loop filter to have a second-order noise shaping. To realize a noise coupled bandpass modulator, we need to implement Z -2 delay block in the analog domain, but the proposed modulator uses only Z -1 delay blocks to apply the noise coupling technique. This simplifies the structure of the modulator and reduces the power consumption, area, and nonlinearity of the modulator. The error in the coupling path is considered and the effect of it on the modulator resolution is analyzed. According to the simulation results, the proposed modulator results in SNR = 84.9 dB at 80 MHz sampling frequency, 200 KHz bandwidth and OSR = 200.

show abstract

Section: Introductionmentioning

confidence: 99%

Filter Loop Reduction in DT BP Sigma-Delta Modulator Assisted by Noise Coupling Technique

Gholami¹,

Ardeshir²,

Naimi³

2014

IJISA

View full text Add to dashboard Cite

show abstract

A tunable SC bandpass delta-sigma modulator with noise-coupled architecture

Huang

Wang

2011

2011 IEEE 54th International Midwest Symposium on Circuits and Systems (MWSCAS)

View full text Add to dashboard Cite

Noise-Coupled Image Rejection Architecture of Complex Bandpass .DELTA..SIGMA.AD Modulator

San

Kobayashi

2010

IEICE Trans. Fundamentals

Self Cite

View full text Add to dashboard Cite

This paper proposes a new realization technique of image rejection function by noise-coupling architecture, which is used for a complex bandpass ΔΣAD modulator. The complex bandpass ΔΣAD modulator processes just input I and Q signals, not image signals, and the AD conversion can be realized with low power dissipation. It realizes an asymmetric noise-shaped spectra, which is desirable for such low-IF receiver applications. However, the performance of the complex bandpass ΔΣAD modulator suffers from the mismatch between internal analog I and Q paths. I/Q path mismatch causes an image signal, and the quantization noise of the mirror image band aliases into the desired signal band, which degrades the SQNDR (Signal to Quantization Noise and Distortion Ratio) of the modulator. In our proposed modulator architecture, an extra notch for image rejection is realized by noise-coupled topology. We just add some passive capacitors and switches to the modulator; the additional integrator circuit composed of an operational amplifier in the conventional image rejection realization is not necessary. Therefore, the performance of the complex modulator can be effectively raised without additional power dissipation. We have performed simulation with MATLAB to confirm the validity of the proposed architecture. The simulation results show that the proposed architecture can achieve the realization of image-rejection effectively, and improve the SQNDR of the complex bandpass ΔΣAD modulator.

show abstract

Complex bandpass ΔΣAD modulator with noise-coupled image rejection

Cited by 3 publications

References 8 publications

Filter Loop Reduction in DT BP Sigma-Delta Modulator Assisted by Noise Coupling Technique

Filter Loop Reduction in DT BP Sigma-Delta Modulator Assisted by Noise Coupling Technique

A tunable SC bandpass delta-sigma modulator with noise-coupled architecture

Noise-Coupled Image Rejection Architecture of Complex Bandpass .DELTA..SIGMA.AD Modulator

Contact Info

Product

Resources

About