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Design >> RF Design >> square law mixer simulation
https://designers-guide.org/forum/YaBB.pl?num=1396883574

Message started by mixed_signal on Apr 7^th, 2014, 8:12am

Title: square law mixer simulation
Post by mixed_signal on Apr 7^th, 2014, 8:12am

Hi,
I am simulating a square law mixer and the input to it is RF+LO. What is the best way to combine RF+LO?

Use 2 ports and vcvs to add? But this screws matching since vcvs has high Rin and low Rout. If I put 50 ohm in parallel with port then I get incorrect NF?

Put 2 ports in series? I want to simulate noise figure and matching.

Title: Re: square law mixer simulation
Post by aaron_do on Apr 7^th, 2014, 5:53pm

How do you intend to do it in the real design? Transformer? If you just want some kind of ideal simulation, then you could use a PORT for the RF input, and put a voltage source in series for the LO. But in the final design, it sounds like your LO is going to affect your input matching...

regards,
Aaron

Title: Re: square law mixer simulation
Post by mixed_signal on Apr 9^th, 2014, 8:08am

Hi Aaron,

I am using a cyclic combiner using L and C networks. If I use a voltage source then will spectreRF properly simulate large signal effects of LO since its not a port.

Title: Re: square law mixer simulation
Post by mixed_signal on Apr 9^th, 2014, 8:31am

Hi Aaron,
I am using offchip transformer to generate LO+, LO-, RF+, RF- though and a cyclic combiner afterwards. I have posted a test setup question in RF measurements section. You may have a look.