ADF7021 (error)

http://www.analog.com/media/en/technical-documentation/data-sheets/ADF7021-N.pdf Have you read?

Where are you located? This freq is used by UHF and other things and is not allowed in the US.

Clem

Dear Clem Martins,

Thank you so much for your reply!

- I read datasheets many times, many times.

- I am in Viet Nam. This is a test in Lab. I can adjust frequency into VHF, UHF by my software.

I have a problem with receive mode!

Can you help me, please?

Many thanks,

NA

Have you tried other frequencies? Make sure the bandwidth are the same on both sides. Also is there other devices in the lab at the same frequency?

Read ADF7021 for some more considerations.

yes, I tried some other frequencies.

yes, same bandwidth

yes, I am very sure because I have a spectrum analyzer.

I did this many times. I also donwloaded codes from the internet with reference.

finally, same results. There is STILL  a pulse ( frequency from 150hz - 250hz , I see on the Ossiloscope) in pin TxRxDATA ( pin 34). And, when I turned off the transmit kit, there is still that pulse in receive kit ( at in 34).

I don't understand why, Clem Martins.

NA

So you have this setup:

Note that Mcu TxDATA goes to TxRxCLK and RxDATA goes to TxRxDATA.

Clem

I researched the topic ADF7021 for some more considerations.

yes, in transmit kit, I push data in TxRxCLK. And in receive kit, I should get data in TxRxData ( 34 pin). But, there is ALWAYS a pulse at this pin.

I think that trasmit mode is okay.

there is a problem in receive mode that makes a pulse at pin 34.

I researched the topic ADF7021 for some more considerations.

yes, in transmit kit, I push data in TxRxCLK. And in receive kit, I should get data in TxRxData ( 34 pin). But, there is ALWAYS a pulse at this pin.

I think that trasmit mode is okay.

there is a problem in receive mode that makes a pulse at pin 34.

I am turning in since very late here. But you may want to try https://ez.analog.com/welcome

for their blogs.

Clem

  https://ez.analog.com/welcome

They will say:

" I’m sorry. Questions on ISM and Licensed Band Transceivers (products with ADF7XXX part numbers) are not  handled on Engineerzone and should be directed to your local sales organization"

I think you'll need to do that, i.e. contact the local AD sales office, otherwise it is just luck if someone has used this part and responds.

Anyway, you didn't mention if the clock pin has pulses on it or not. If you see no pulses then the data should be ignored.

It might be normal for the data line to have pulses on it, I don't know, this is just a guess. I've not used the part, so can only guess.

What happens if the circuit is in a screening enclosure and no antenna input to the outside world? Perhaps your bandwidth is

too high, and you're picking up other stuff on nearby frequencies (435MHz area is usually busy).

There is no real intelligence in the IC you're using, it is a raw receiver.

I think you'll need to do that, i.e. contact the local AD sales office, otherwise it is just luck if someone has used this part and responds.

Anyway, you didn't mention if the clock pin has pulses on it or not. If you see no pulses then the data should be ignored.

It might be normal for the data line to have pulses on it, I don't know, this is just a guess. I've not used the part, so can only guess.

What happens if the circuit is in a screening enclosure and no antenna input to the outside world? Perhaps your bandwidth is

too high, and you're picking up other stuff on nearby frequencies (435MHz area is usually busy).

There is no real intelligence in the IC you're using, it is a raw receiver.