Unfortunately, it is not practical to simulate this circuit in spice.
For the oscillator you can use the Voltage Source configured as a sine or maybe a pulse source.
The other components however (ERA1/2/3/5 or MGA64135/MGA86576 MMIC, VK200 choke and 1N23 diode) are hard to simulate because there do not seem to be any publicly available spice models.
There also seems to be no model for how the diode couples into the waveguide.

There may be models available within dedicated commercial microwave simulation tools but they will probably be s-parameters models and not spice models. They may also be encrypted to the commercial tool.

You may find QUCS or Qucs-Studio a more useful tool to use for microwave design work:
http://qucs.sourceforge.net/
https://dd6um.darc.de/QucsStudio/about.html

Procurei simuladores de microondas e o software disponível é muito complicado de se trabalhar. Preciso de ajuda. Enviei um e-mail para signality.co.uk
thanks for help

I looked for microwave simulators and the software available is very complicated to work with. Need help. I sent an email to signality.co.uk
thanks for help

@limasp,

I haven't seen your email yet so I do not know for sure what you are trying to build.

You could try contacting me at:

myusername @ easyeda.com

Is this what you are trying to build?

https://www.qsl.net/i/iw1fyv/marker_en.html



Have a look at:

https://www.bobatkins.com/radio/10GHz_diode_detector_mixer.html



and:

https://www.g0mrf.com/source2.htm