Official bladeRF forum

Looking to generate gps signals for some tests but I do not want them escaping my room for the most part. Definitely don't want the cops showing up saying that I interfered with a plane.

I have a bladeRF x40 and the receiver will be a android smartphone. Ideally i'd like to transmit gps signals only a few feet max. Any idea?

Hi,
the antenna doesn't really matter here - a wire cut to the frequency would do.

the best way to make sure you're not violating law or causing harm is to use a shielded box for such tests. it's not easy to make & test, buying is rather costly.

other way is to use attenuators on the output of the tx and trim the signal to the value that your phone is picking up the signal only from a very close proximity. it will not give you 100%, but reduce chances of getting into troubles.

don't leave such working setup ON for long periods of time, as gps receivers can sync to low amplitude signals
b.r.