Author Topic: Protection for GPS input  (Read 1162 times)

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Offline rakeshm55Topic starter

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Protection for GPS input
« on: May 11, 2019, 12:31:42 pm »
Hi,
How to protect Antenna input signals from ESD?

I have connected a low capacitance ESD diode. What is the standard mechanism used to protect GPS module (Sensitive to ESD) from ESD faults.
 

Offline Yansi

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Re: Protection for GPS input
« Reply #1 on: May 11, 2019, 02:25:05 pm »
You have your answer on the schematic.

Other option is to use a diode clamp.
 

Offline dmills

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Re: Protection for GPS input
« Reply #2 on: May 11, 2019, 02:46:06 pm »
A Quarter wave stub to ground should work and can be printed right onto the board.

regards, Dan.
 

Offline radiolistener

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Re: Protection for GPS input
« Reply #3 on: May 11, 2019, 03:54:33 pm »
Here is typical solution to protect from overvoltage. In your case, you can use 1:1 RF transformer.

« Last Edit: May 11, 2019, 03:56:15 pm by radiolistener »
 

Offline Yansi

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Re: Protection for GPS input
« Reply #4 on: May 11, 2019, 05:39:11 pm »
A Quarter wave stub to ground should work and can be printed right onto the board.

regards, Dan.

Will ruin impedance matching and will work likely only rather narrowband.

Also please keep in mind that GPS is like what... 1600MHz? The 1/4 wave stub will be unacceptably long for most applications on a PCB.
 

Offline dmills

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Re: Protection for GPS input
« Reply #5 on: May 11, 2019, 07:07:32 pm »
GPS is rather narrow band, CA is only a MHz wide so less then 0.1% fractional bandwidth, and at ~1600MHz a quarter wave shorted stub will be less then 4.5cm long.

I don't see a problem with a stub line, and if you play it right you can also use it as the choke for the DC to power the antenna LNA.

Regards, Dan.
 


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