Re: Understanding Pulsed signal Demodulation and decimation in GNU Radio

Ohh... bandwidth is just half the sample rate of course. So the cutoff
has to be 50k and transition 20k for example.

Am 21.07.22 um 10:45 schrieb Fabian Schwartau:
> Hi Isaac,
>
> I am not sure what you are trying to achive. However, your low pass
> filter seems to be set up incorrectly. You have a signal with 1MHz and
> 10MHz samplerate. Your low-pass filter has a cutoff at 5MHz and then
> down-samples by 100. If you want to make sure that there are no
> frequency components aliased during the downsampling step, you should
> have a cutoff of 100kHz or below. When you set the cutoff to 100k and
> the transition width to 50k, you get a nice constant rect at the output.
>
> Hope that helps.
> Best,
> Fabian
>
> Am 20.07.22 um 19:03 schrieb isaac mario tupac davila:
>> Hello everyone
>>
>> My name is Isaac. I'm dealing with a curious behaviour that I can't
>> understand...
>>
>> I'm generating my pulsed signal by multiplying a vector source and a
>> signal source. Then I'm multiplying this pulsed signal with a
>> continuous signal source at the same frequency, passing then for a low
>> pass filter and seeing it in a time sink block.
>>
>> The result should be a set of rectangles with the same amplitude and
>> period. The curious thing here is that the amplitude varies in time
>> (from 0 to max amplitude and vice versa). Any idea why the amplitude
>> varies in time?
>>
>> I attach the flowgraph just in case.
>>
>> Any idea or help will be appreciated.
>> Thanks
>> Isaac t.
>>
>
>