As a part of understanding how to optimize matching networks in cadence I am designing a matching network to match 10 ohm load to 50 ohms source at 6Ghz. I am using simple L matching network and I know all the equations required. I come up with the required values of L and C. Simulation shows real part of input impedance to be 50 ohms when I use ideal inductor and capacitor. Now I keep ideal capacitor and use inductor provided by tsmc 0.13um process. As expected (because of component Q) real part of input impedance is dropped to 45 ohms. I want to know how I can use cadence to automatically optimize this or any other matching network. I found that ADE GXL can be used for optimization but when I read the manual I thought it can be used for only Anlog Circuits (matching devices etc). Please let me know how I can use cadence to do the optimization of matching networks.
Thanks in Advance
Hi nadroit, I'm not sure if I sent this already....if so, my apologies for the duplication. You should be able to use ADE XL with all spectre analyses (analog, mixed signal, RF). It sounds like spectre sp analysis (linear s-parameter analysis) is what you are looking for. You would use ports on the input and output. best regards, Tawna
Customer Support Director - Analog/Mixed-Signal/RF AEs
Cadence Design Systems, Inc.
In reply to Tawna:
Thanks for the reply. I know how to do .sp analysis with ADE XL. I was trying to use optimization in ADE GXL (local and global) to tune the values of L and C in L matching network. I could run the simulation with out errors but GXL did not give me optimized values. I searched the GXL documentation and found out the optimization was used for lot of Analog Designs (eg optimising opamp gain etc). My question is can I use the optimization for RF applications like fine tunning the matching netwrok? if yes do you have any tutorial which I can follow?
In reply to nadroit:
Hi nadroit, Unfortunately, I do not have any examples for doing this (and I agree - one is needed).Would you please file a Service Request with Cadence Customer Support so an AE canwork on this for you? (In fact, it likely could be me working on it!) http://support.cadence.com . You should be able to use ADE GXL optimization for RF applications without any issues. best regards, Tawna
Again thanks for the reply. I thought that it should be simple to run RF optmization on GXL but could not figure it out. There might some small thing I doing wrong. It would be great if I can get some kind of tutorial from cadence. I will post the request on the site you mentioned but it looks like I need to know some licence information to open the account for that site. Meantime if you come accross some tutorial on RF optimization using GXL please do share.
Hi nadroit, You do have to be a Cadence Customer on maintenance to access Cadence Online Support.If you are a University student, you'll need to talk to your Cadence liaison there to file a Service Request.There are no tutorials yet for this...but I think it's a great idea! I'm sure it would be simple...but you would need to file a Service Request to get help on this issue. best regards, Tawna
You can read chapter-2 of the Virtuoso Analog Design Environment GXL User Guide on circuit optimization. It has most of the information you need to run an optimization.
I was looking for tutorial on Optimization of matching network in Cadence and came across this particular RF design forum topic. Is there any tutorial available now? If yes, please let me know where can I get it or if there is any other better way you can suggest. I tried to find in GXL user manual but couldn't get.
In reply to Varun Gupta:
I'm not aware of a specific tutorial on optimisation of matching networks but you can find a section on optimisation in the Advanced Statistical Analysis for Variation Aware Design Rapid Adoption Kit.
In reply to Andrew Beckett:
In essence it's the same - of course you can plot various metrics on an Smith Chart using the Direct Plot form having done an sp analysis. There is fundamentally no difference between optimising the circuit or optimising your matching components - you have a set of goals, and things to vary, and it will optimise to meet those goals.
If you want to manually tune the variables, you could use the "interactive" or "real-time" tuning feature that is in ADE Explorer (in IC617).