Electronic – Active RF Antenna power PCB layout: where to place the inductor for a bias tee

"Biasing" in this context basically means: to provide power to the active antenna

Active GPS antennas have a built-in amplifier (you'll see the term LNA floating around, Low Noise Amplifier), near the actual antenna element. The signals from GPS are so small that losses from a long (~10cm or more) wire are incredibly detrimental to the signal.

For any amplifier to work, it needs power (a positive and a return, aka ground). Most GPS connections use SMA connectors, and they only have 2 pins. One for ground, and one for "data". So how do you "send power" to the amplifier that is built into the active GPS receiver when we don't have an extra power pin? This is where the inductor comes in - it's a trick to share the positive power line with the GPS "data" signal line.

This works because the GPS data is completely AC data. The inductor decouples the output signal from the high impedance positive power rail, allowing the output signal's AC component (the actual GPS RF data) to come back along the power line. Or another way to say it, prevents the power rail from washing out the signal that we care about.

And yes, that extra 22pF capacitor is just to help provide clean (low noise) power to the inductor. If there is extra noise on the power line, that noise can get through the inductor and wash out the GPS signal that you care about.

Doing what was done in that blog post should work fine in this case as well.

I'd stick the inductor vertically on the microstrip. Be sure to place it on the far side of C1.

Tack the connecting wire to the top of the vertically mounted inductor, and either keep it short enough it won't catch on anything, or glue the wire to the PCB as strain relief.

It'd probably be a good idea to bypass the power to the inductor as well, so it doesn't form an accidental antenna or potentially radiate RF. If you're using the same voltage for VCC as the bias, I'd just run the wire to one end of C4. Otherwise, tack a SMT cap to ground somewhere, and pass the bias connection by the cap terminal.