Filter

No filter -> 3 GHz

Filtered -> 3 GHz

Under Test

VHF Band 3 filter

As you have seen on the other section of this wiki we need to filter uppers harmonics present at the output of the USRP, for example from the WBX daughterboard

We have tested the RBP-220W from Minicircuit, a pass band for the band 3.

The Filter give a flat response from 178 to 275 Mhz when soldered on the amplifier input strip line, the insertion loss on the same frequency range is equal to 1 dB.

This is what we get when sweeping the signal from 6 to 402 MHz (higher was always better than 60 dB of att, measured up to 6.5 GHz):

The response at various frequency indicated by markers from 1 to 10 (attenuation in dB of the filter from 120 to 350 MHz)