Five karstification phases are recognized and analysed in the Mesozoic carbonate sequences of the External and Internal Subbetic (Betic Cordilleras, southern Spain). These phases are related to important stratigraphic discontinuities in the following ages: (1) Intra-Carixian, (2) Early–Middle Jurassic boundary, (3) late Bathonian–early Callovian, (4) Intra-Kimmeridgian, and (6) late Albian. The...

The combination of traditional polyphase filter architecture with a new multiplier-rich FPGA family provides the means to build wideband (GHz), flexible and high dynamic range filterbanks and FX correlators using a small number of commodity ICs. A 2GHz 4k-channel unit, serving as a prototype for next generation ATNF correlators and as an SKA demonstrator, is described. Polyphase Digital Filterb...

This paper addresses a new approach for the design of multiband filters with step like magnitude responses and extremely flat, weighted passbands down to μdBs. Our new technique can also be used for the multiband step-wise approximation of arbitrary filter magnitude responses with precise transition band control. One marked advantage of the technique is that our basic building blocks are the mo...

In this paper, we derive a polyphase analysis to determine the optimum filters in a subband adaptive filter (SAF) system. The structure of this optimum solution deviates from the standard SAF approach and presents its best possible solution only as an approximation. Besides this new insight into SAF error sources, the discussed analysis allows to calculate the optimum subband responses and the ...

Fast-scanning quadrupoles more representatively record LA-ICP-MS transient fluid inclusion signals. This allows to (1) target smaller inclusions than before; (2) accurately polyphase signals; (3) better characterise chemistry.

Frequency-response masking (FRM) approach is a very efficient method for designing linear-phase FIR digital filters with general passbands and sharp transition bands. The FRM approach has recently been adapted to design cosine-modulated filter banks (CMFB). The resulting structure is a two-stage filter formed by the polyphase decomposition of the base filter in cascade with the decomposition of...

In this contribution a generalized spectral refinement method of speech signals will be presented which can either be applied at a preprocessing stage before or at a postprocessing stage after a conventional frequency analysis. The refinement approach is based on a linear combination of weighted and shifted input speech signal segments. By applying the refinement method either in time or in the...

The polyphase filter approach to quadrature demodulation is presented. It is shown to be well suited for the implementation of purpose-designed high performance, wide bandwidth quadrature demodulators in low-cost Field-Programmable Gate Array (FPGA) technology. The duplicated polyphase filter approach is introduced, as a way to increase the maximum allowable input signal bandwidth while maintai...