We are in the process of FCC certification. The certification company wants to test the module with UFL connector. In their testing they are getting a difference of 4 dBm with chip antenna and with UFL connector.
I need some clarification on grounding connection to UFL connector. The chip antenna having two ground connections, one path is directly connected to ground and another path is connected to ground through an Inductor (or) Resistor. Which ground I need to use for UFL connector?
Is there any difference between the two grounds? We used the direct ground path in testing.
Comment from support engineer on our portal: "From the datasheet, the GND pins are 1-3,14,15,22,31-36. So the UFL connector's GND should be connected to these pins."
You should use direct GND for your test. Basically there is no difference between direct GND and antenna GND for DC performance. But for RF performance, the Antenna GND may take the role of antenna match, please refer to the antenna datasheet for some information.