QUESTION

Question

Hello,

We are using the M20048-1 and / or M20050-1 GPS modules in one of our designs. This is a portable personal dosimeter that is typically worn on a belt or on a coat around chest, to get accurate radiation readings.

We are now busy redesigning the main PCB and we are forced to move the GPS module from the top side (south) to the right side (east) of the PCB. Do you think this will affect the performance of the PCB, how do we make sure that we maximize the signal gain of the GPS module?

Many thanks,

Blazej Szyler

Answer 1

Hello Blazej,

The antenna module works best when the antenna is placed along the longest edge of the device that will be facing the sky. Rotating the antenna will tend to drop the antenna reception so it may take longer to get the same accuracy as the antenna facing the sky but you should still be able to receive a location fix.

Best regards,

Geoff S.

Answer 2

Hello Geoff,

Thank you for your response. I will test the new PCB once it arrives from manufacturer. I do have additional question, are we able to use tuning components to get the best performance? If so what is the process of doing so?

Regards,

Blazej

Answer 3

Hello Blazej,

You will need to lift C1 and place an RF coax in Pin 4 then adjust the value of L1 until you reach 50 ohms on the Smith chart or a return loss of better than -10dB. You can also ajdust R1 by placing a capacitor or inductor to tune the antenna to 50 ohms.

You could also us the receive signal strength in the software and adjust R1 and L1 until you get the strongest signal strength.

Best regards,

Geoff S.