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Hi, I am rather new to CL but totally amazed!! I need to build a DC-Bias for an active GPS Antenna ( max 2.7 V max 15 mA) and feed its output to a Spectrum Analyzer. I know that I need a shunt coil and a series Cap but I have problem to simulate it (Function Generator at 1.5 GHz= RF input). Could you guys help? Thanks

Hi Y3g,

Welcome to CL.

Have a careful read of:

https://www.circuitlab.com/docs/faq/

then:

https://www.circuitlab.com/docs/

then have a look at some of these:

https://www.circuitlab.com/user/CircuitLab/

and by then, you might like to have a look at:

:)

Of course, a real circuit will behave very differently from this example. The actual component values may be different and they will all have parasitic parallel capacitances and series inductances ...

To get anywhere near a realistic simulation, you'll have to add all the major parasitics into the circuit diagram.

And add some to allow for the physical layout.

You'll get some idea using CL but at 1.5GHz it is not an ideal tool.

Well, first of all many thanks !!! I will try to assemble it with lumped elements and will use an osciloscope or an spectrum analyzer with dc block to verify the values. But i like the tool anyhow and will "spread the word" for it.

Thanks a lot Y3g

For RF work, QUCS may be a better tool. It has a reasonable collection of dedicated RF components and models, such as components with parasitics and microstrip stuff so you can more accurately simulate things on a PCB.

QUCS is still under heavy development but is probably quite a bit further along the road than CL. That said, it is a download and install tool and has none of the CL cloudy, shary, quick sketchy, bloggyness.

QUCS is FOSS and runs fine natively on both Linux and Windows. Think it's OK on OSX too.

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