Dear Analog Devices,
We are trying to do a demo for a customer in which we would like to use the LTC5562 DC2483A-B evaluation board (LTC5562 mixer as a downconverter) spannered in to our set-up. For this demo we only need one set of frequencies:
RF = 5.5GHz
LO = 7.1GHz
IF = 1.6GHz (LO - RF)
There is a major hang up though: On the evaluation board the RF port of the mixer has a 1:1 transformer fitted, the TC1-1-13M+ from Mini Circuits, which doesn't go up to 5.5GHz. Mini Circuits do have transformers that go up to 6GHz, even 8GHz, BUT they are not footprint compatible. Does anyone here know of any transformers that can fit on the evaluation board to allow us to tune the LTC5562 to the aforementioned frequencies. For the IF port there are footprint compatible alternatives, while the LO can be single-endedly driven. The RF port is holding us up though.
Have you looked at Macom offerings?
I took a quick look and and there are some SMT transformers that you may be able to hack onto your board with some small surgery.
Here is a 8GHz 1:1 Balun…
In the LTC5562 datasheet, pages 12, 13, 15 and 26 all show some options for transformers that operate at 5.5GHz.
Thanks,Weston SapiaSr. RF Applications EngineerAnalog Devices
While the Mini-Circuits 6 and 8GHz transformers do not have exact footprint as the TC1-1-13M+. They are close enough that you can fit them onto the eval board with some hacking. I have done it many times…
Weston, thank you for your reply. I read the datasheets in the first place and saw the proposed alternative for the high frequency operation, the TCM1-83X+ from Mini Circuits, except there is a problem: there is no footprint compatibility for the LTC5562 evaluation board. You can still use it but you have to somehow short-circuit pins 5 and 6, which I found compromises the RF performance, especially the conversion loss, by a few dB. I think the TCM1-63AX+ might be a better option for the very evaluation board. The evaluation board I am on about is the DC2483A-B, with the mixer configured as a down-converter.
This is how all the 7-8GHz data was collected for the datasheet. We also used the standard evaluation board. That said, the TCM1-63AX+ is definitely an option for your use case as well.