cast Bandwidth of transducer

Hi, We have L15-HD transducer. We would like to know what is the bandwidth of this transducer. In the manual, it said that the transducer frequency range is 5 - 15 MHz. Does the bandwidth depend on the settings we select? Can we change the bandwidth ? Regards, Ali

Jun 02 '23 15:06 AliKafaei

Yes, correct, 5-15, there are no options to change bandwidth, Clarius optimizes each preset and depth setting for transmit and receive frequencies.

Jun 02 '23 15:06 clariusk

So when you say optimizing, does that mean it changes the bandwidth or it is always fixed?

Jun 02 '23 15:06 AliKafaei

It is fixed, but the frequency slides as a function of depth

Jun 02 '23 16:06 clariusk

Would you please clarify more the frequency slides?

Jun 02 '23 16:06 AliKafaei

so if we transmit at say 10 MHz, we may adjust the receive filtering from 15MHz in the near field, and linearly slide it to the imaging depth to say 8MHz, these are configured per preset and depth range

Jun 02 '23 17:06 clariusk

Does the sliding info per depth is also saved so that we know the bandwidth for each depth ?

Jun 02 '23 17:06 AliKafaei

if you have specific presets and probe models, we can give you that info

Jun 02 '23 17:06 clariusk

Thanks, we will contact you when we decide about the specific presets we are going to use

Jun 02 '23 17:06 AliKafaei

Hi, We use two specific settings: 1- MSK, maximum depth = 4 cm 2- RF data, maximum depth = 4 cm I am not sure that MSK preset also can provide RF data or not.

Jun 05 '23 14:06 AliKafaei

Transmit of 14MHz Receive from 15MHz to 10MHz over 4cm RF does not go through demodulation, therefore no RX applied

Jun 05 '23 17:06 clariusk

Sorry, by RX, do you mean Recieve filtering ?

Jun 05 '23 17:06 AliKafaei

yes, correct

Jun 05 '23 18:06 clariusk

Hi, We have done an experiment to verify the spectrum of RF data. We put a metal plate in a container filled with distilled water. We get the received RF data and took FFT (we considered that the sampling frequency is 60 Mhz as it was mentioned in the yml file). This is the spectrum : This is the Bmode This is from yml file The spectrum does not match with the specified center frequency in the yml file.

Jun 23 '23 17:06 AliKafaei

Hi, Just a kind reminder about the bandwidth probe. We are going to collect data soon. Regards,

Jul 11 '23 16:07 AliKafaei

thanks for the graph and data, we're not too sure, as our acoustic measurements show probes range from 9.5-10.5mhz center frequency.

Jul 11 '23 18:07 clariusk

Is it possible that the sampling frequency is different than 60 (the value mentioned)? I used this value to generate the graphs.

Jul 13 '23 16:07 AliKafaei

We tested Clarius using two modes, research and MSK, and calculated the spectrum using multi-taper method. image (33)

image (34)

According to yml file the center frequency of MSK and research modes are 14 Mhz and 10 Mhz (cannot be verified in the figures), respectively. We also would like to know why there are contents outside of bandwidth in research mode.

Sep 19 '23 19:09 AliKafaei