QUESTION

Question

Hello,

I am integrating a M20048-1 GPS receiver into a project that I am designing. I just ordered the chip, and I am currently trying to optimize the tuning components L1 and R1. The datasheet does not contain detailed information regarding tuning of the antenna. Can you please provide support to enable the correct tuning of the receiver's antenna?

As far as I can tell, is the 1.8nH inductor supposed to remain, and the 0-ohm resistor tuning resistor on the AT1 pin supposed to be replaced with either a capacitor or inductor until tuned? What equipment do I need to tune it? Is there a way to tune with software? While tuning, what does my environment need to look like? Can the AT1 and AT2 pins be tied to ground?

Thanks,

Sam

Answer 1

Hi Sam,

You will need a VNA to check the resonance of the antenna. AT1 and AT2 can both be changed. Have you checked the resonance with the tuning components suggested in the datasheet?

Best regards,

Yu Kai Yeung

Comments

Hi Yu,

In order to check the resonance of the antenna, where would you recommend putting breakout pins on my PCB in order to properly run the VNA analysis? The suggested tuning components are more just place holders, no? I am not sure what a 0 ohm resistor would really do in this case.

Thanks,

Sam