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AD9361 Rx and Tx clock rate and RF bandwidth

Question asked by Andrew1989 on Jul 29, 2016
Latest reply on Oct 19, 2016 by marutibk143

Hello ! We are working with FMCOMMS2 ZedBoard design for a while and now we are considering bandwidths of Rx and Tx signal paths, because we want to transmit noise-like wideband signal. As far as I understand we can set different values of Rx and Tx samle rates, for example, like this


{983040000, 61440000, 30720000, 15360000, 15360000, 15360000},//uint32_t    rx_path_clock_frequencies[6] *** adi,rx-path-clock-frequencies

{983040000, 30720000, 30720000, 30720000, 30720000, 30720000} ,//uint32_t     tx_path_clock_frequencies[6] *** adi,tx-path-clock-frequencies


and RF bandwidths


    56000000,//rf_rx_bandwidth_hz *** adi,rf-rx-bandwidth-hz

    56000000,//rf_tx_bandwidth_hz *** adi,rf-tx-bandwidth-hz


When we check sample rates in Vivado SDK with commands tx_samp_freq? and  rx_samp_freq? it returns above mentioned different values, but when we check Tx_frame and RX_frame test points on AD9361, clock frequencies appear to be the same and equal 15,36 MHz (and also ILA captured signals adc_valid and dac_valid are the same). Is it possible to make them different or this is normal behavior ? And another question: what is connection between sample rate and RF bandwidth ? Which values we should set for it ?