Building a PIN Diode Model in ADS

[RFan]

Hi，
I am trying to build a nonlinear model of a PIN diode following the NXP documentation. (https://www.nxp.com.cn/docs/en/application-note/AN10173.pdf) But I could not find the corresponding PinDiode and PinDiodeModel in Figure 6 of the document in ADS. My ADS version is 2023. I saw related posts, but no reply. (https://www.edaboard.com/threads/building-ads-pin-diode-model.230006/) How can I find these two models? (or how should I set Vi in ADS2023) Please see the picture below.(These contents are from machine translation, maybe the tone is a bit stiff)

 

[BigBoss]

PIN Diode Model has been changed and the model declaration block is not valid anymore.
They should be similar but now exact. Because the App. Note is pretty old and the model definition was different at that time. You can request it from NXP.

 

[RFan]

PIN Diode Model has been changed and the model declaration block is not valid anymore.
They should be similar but now exact. Because the App. Note is pretty old and the model definition was different at that time. You can request it from NXP.

Think you for your reply.I also want to ask, if a model similar to Figure 6 is established in ADS, can it be exported as a .cir or .net file for simulation in CST？

 

[dick_freebird]

Most simulators will accept a basic SPICE model in some
compatibility mode. When you get to more modern stuff,
uptake of some other guy's customizations is more iffy.
I'd start with asking the mfr for exactly what you want and
see if it's already on the shelf. Unless this is more about
the learning experience than an efficiently arrived-at outcome.

 

[RFan]

Thanks for your patience, this may have been a stupid question in the beginning, but I found the solution I was looking for. I will make some brief descriptions here so that friends with similar problems can solve them faster.

First, the problem I want to solve is how to emulate diodes in CST. In the beginning, ADS was used because the manufacturer only provided ADS models. Taking a detour here, I think ADS can help me generate SPICE files. (such as .cir and .net, which can be accepted by CST) In fact, if you want to apply the SPICE model in CST, it is best to find a product that the manufacturer provides SPICE for design, so that you don't have to build it yourself, hahaha.

Secondly, CST has certain requirements for acceptable file formats, and we should pay attention to the following points:

(1) The .lib file provided by the manufacturer is used to define the device. CST needs a .cir or .net file, which is used to describe the circuit file. The .cir file can be implemented by directly modifying the file suffix.

(2) After modifying the file type, it is necessary to define a sub-circuit, which only contains a diode. (Note that two ports are defined.) For example:
.subckt subcirA 1 2
...
.ends

(3) In the CST version I use, the .cir file is required to have the same name as the defined subcircuit (this may be the basic knowledge of SPICE, I don't know). For(2), that is subcirA.cir.

(4) Give a complete example:
.subckt subcirA 1 2
D1 1 2 Diode A
.model DioadeA D
+is=15E-15
+n=.9
.ends

 

[dick_freebird]

OK, but that isn't much of a PIN diode model, which is mostly about the C-V swing (Coff) and the forward conductivity modulation (Ron) if you are switching RF power rather than pulling frequency varactor style. Neither of those have anything but default values (which may vary by dialect).

Presumably you'll find PIN diode model realism at the bottom of some Internet rabbit hole or other....