TRF3722: The device is giving loss

Hi

Sorry for the late reply. I have tried the suggestions given on the post shared by you. Everything is fine as per the suggestions. I have checked the device soldering as well. Is there any problem with my schematic?

Hi

Awaiting for the reply....

Hi Sarika,

Although it was a little difficult read, after looking at your schematics, I don't see any obvious issues. However, I would like to ask you if you could provide a screenshot of your output, that also includes the LO output and the sidebands as well. This could help give me a better understand as to what the cause of the issues is.
Also how exactly are you sourcing your inputs. Test Equipment? DAC?

Regards,
Oscar

Hello Oscar,

The inputs are provided using DDS. PFA for the screenshots.

Hi

IF = 189.54MHz,
Output RF = 2.34045GHz and
LO = 2158MHz.

Hi Sarika,

Thank you for providing the screenshots. I have some further questions that will help me determine the root of the problem.

1. When you checked the soldering of the device, were you also able to verify the soldering of the power pad underneath the device?
2. When checking the voltages, did you measure at the pins of the device?
3. Lastly can you provide your register settings?

Regards,
Oscar

Hello Oscar,

Yes the power pad was soldered properly and that has been verified with experts here.
The voltages were measure at the ferrite beads.
We are using the same device in another design as well, and it`s working there, so have checked impedance at pins referring the other card.
The register values:

QM

reg_map_i(0) <= "01101000000100000000000001001001"; --9
reg_map_i(1) <= "10010000100000000001000110001010"; --A
reg_map_i(2) <= "00011111101010101010101010101011"; --B
reg_map_i(3) <= "10001000000111000000000000001100"; --C
reg_map_i(4) <= "00010001100010101010000011001101"; --D
reg_map_i(5) <= "10100100011101010011000000001110"; --E

Hi Sarika,

Using your configuration settings, I uploaded them on my own TRF3722 set-up and confirmed that there is nothing wrong with your register settings. I have attached images of the LO, the LO with both sidebands (I did not use quadrature inputs, therefore both sidebands will be present) and the RF output. 

I tried to capture the LO and the RF output with the same settings that you had in your captures. But a few things that I noticed were that your LO output is much noisier and even has some spurs. Also with the LO @ 2158MHz and the BB input @ 189.54MHz, the resulting RF output would be (189.54 + 2158) = 2347.54MHz. In your image I see a tone that would land at this frequency (D4 in your first image), however I am not entirely sure what the other tones in that image are.

I would like to ask for another screenshot of your RF output, but this time have the center frequency be the LO frequency (2158 MHz) and the span large enough to capture both sidebands. I believe 500 MHz for the span should be sufficient as I have that same configuration in my image. 

Another couple of items to check would be the quality of your reference signal of the TRF3722, as well as ensuring that there aren't any noisy power supplies feeding into the modulator.

Regards,

Oscar