In-line GPS amplifier

[TheOne]

I was having trouble with my GPS nav system in my car loosing the sat signal during rainy,cloudy and stormy conditions. So I designed this inline GPS amp using a device from Maxim. **broken link removed**

Below is the circuit, pcb layout and network analyzer response. Works very well. The SOT caps on the input were selected to improve the noise figure of the device.

 

[zachtheterrible]

ya oughta put that in the projects section. thats a cool little circuit to be able to do wut it duz :lol:

 

[carozoynarizota]

TheOne thats a very interesting project. I am looking for a project like this for my own GPS.

I would like to know if you still have the schematics files of your desing and I want to know if you can share them with me.

I can see tha the circuit has like an array of LC filters conforming the antenna, and I wonder if it was hard to tune the antenna with the those varicaps. Wich procedure did you use to achieve this?

I suppose I will need a field meter (I really don't know if thats de correct name in english), and that it won't work at fist time without calibrating it in a lab.

Thanks
Sebastián

 

[TheOne]

This circuit will be very difficult to align without a RF network analyzer (RF tracking gen and spectrum analyzer combined)

 

[carozoynarizota]

Wich software did you use to make the circuit and the PCB? can you send me those files?

 

[Oznog]

On a practical level, there are self-amplifying GPS antennas. I've got one that's maybe 1.5" x1.5"x0.5", magnetic so it sticks to my car roof, and has a tough thin wire that can be slammed in the door seal indefinitely. That thing will aquire in a few seconds and only a tunnel can interfere with it.

 

[carozoynarizota]

On a practical level, there are self-amplifying GPS antennas. I've got one that's maybe 1.5" x1.5"x0.5", magnetic so it sticks to my car roof, and has a tough thin wire that can be slammed in the door seal indefinitely. That thing will aquire in a few seconds and only a tunnel can interfere with it.

I understand as a self amplifying antenna as an antenna module with a built in amplifier, thus it is not a pasive component. And that is what I am trying to do. I think that an amplifier is a must have in my case, ´cause what I am building is a reradiating antenna.

Of course that the practical way maybe is to go and buy one....but I don´t like the easy way 8) And here in Argentina is very expensive.

The problem is that I don´t hace experience and the knowlegde needed to build the right PCB. That´s the reason I am asking for help. Then I will need some help to tune it up.

Bye
Sebastian