Hi all,
The final task for my degree consists of designing a passive MMIC marchand balun that operates in the frequency range of 20GHz-40GHz, with required specifications of:
phase balance < 2 degrees;
magnitude balance < 0.1dB;
S11 < 10.5dB.
The design is being done in AWR, using a 0.25um SiGe process (IHP PDK). I have zero experience in balun design and considering that the EM simulations take 20+ minutes to run, fiddling around with different microstrip configurations (broadside coupling, edge coupling etc) and running the simulation just seems futile and too time consuming.
I have tried using TX Line in AWR in order to get the microstrip characteristics though I am not too confident in the results, as the calculated width of the strip is absurdly large (in terms on MMIC design).
Does anyone have any experience in this field that might be able to offer me some advice with the design?
I can provide images of various attempts and measurements that I have so far if needed.
Any feedback is appreciated.
I am editing this thread for more updated/accurate questioning.
As mentioned in the original post, the process I am using is a 0.25um SiGe BiCMOS one. Looking at the substrate information that is provided within the PDK shows that the dielectric constant for the layers I will be using is 4.1, loss tangent is 0.01. It also provides the thickness for each dielectric layer and the material properties of the metal layers.
Using these within TXLine seems to give this warning:
Here are the dielectric layer properties, I am using layers 4 and 5:
Here are the metal layer properties, I am using ThickAluminum1 and ThickAluminum2:
Am I missing something here? Or can the warnings simply be ignored?
I am currently running an EM simulation while ignoring the warnings to see what the results are like...