logosmallarcetri Arcetri Technical Reports 1/2009


A 16 channel FFT multiplexer

G. Comoretto(1), A. Russo(1), G. Tuccari(2)

(1) INAF Osservatorio Astrofisico di Arcetri
(2) INAF Istituto di Radioastronomia - sez. di Noto

Abstract

A common problem in radio applications is the need to divide a larger bandwidth into smaller, contiguous frequency channels, in order to analyze, transmit, or store the signal using slower equipments. Here a frequency multiplexer based on a polyphase filter and FFT structure is described. The input signal has a 512 MHz bandwidth, sampled by a fast 1.024 GS/s ADC, and the output signals are 15 parallel VLBI data streams, with a bandwidth of 32 MHz each. Both input and output signals are real. The instrument is implemented as a single CORE2 board on the DBBC VLBI digital data acquisition terminal.

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