Performance of subband HFB-based A/D converters

Abstract

Abstract-Subband Hybrid Filter Bank (HFB) structures may replace the classic ones in parallel A/D Converters (ADC). In this paper, subband and original HFB-based A/D converters are simulated and compared in the time domain. For this purpose, firstly a brief survey on subband HFB-based A/D converters is presented. According to the simulations, subband HFB-based ADC exhibits a lower sensitivity to realization errors than classic one. Besides, compensation techniques such as noise canceling may be used for correcting the analog imperfections of subband HFB. This is not possible for classic HFB. The output resolution of subband HFB-based ADC is shown to be better than the one related to classic architecture using FIR synthesis filters with the same order for some exemplary inputs. Computation complexity related to subband architecture is compared with the one due to classic structure. It may be seen that subband HFB-based ADC includes less computational complexity than the classic architecture if an adaptive compensation of analog imperfections is considered.

Time-Division Multiplexing architecture for Hybrid Filter Bank A/D converters

“…Each H k (jΩ) may be substituted by a discrete-time filter H k (e jω ) obtained from periodically extending H k (jΩ) considering only the frequency interval of [ −π T , π T ] (refer to Fig. 3) [8]. If the continuous-time components x(t) and H k (jΩ) are replaced by x[n ′ ] and H k (e jω ), the samplers are eliminated and the discrete-time model of analysis part is obtained.…”

A Wide-Band A/D Converter for the Software-Defined Radio System

“…• Subband HFB structure To obtain the k th row of analysis filter matrix H(e jω ), the analog filter H k (s) is considered in the frequency interval H k1 (z), ..., and H k(M −1) (z) are extracted in the same way that the subband input components are found from the input signal [9].…”

“…Nevertheless, the proposed methods are so limited to some types of errors or to a very specific case [8]. The TDM and subband HFB architectures have been proposed so that an LTI system relates the associated input-outputs since the classical HFB is non-LTI [9], [10]. It is demonstrated that the MIMO HFB ADCs may not only exhibit less sensitivity to the realization errors, but also be corrected using the blind techniques.…”