Duplex 09 PCB goes to Manufacturing

A project log for Cell Phone 4G LTE Repeater / Booster / Femtocell

An outside pole mounted aerial picks up 4G signals which are then filtered, amplified and re-transmitted through a second inside aerial.

capt-flatus-oflahertyCapt. Flatus O'Flaherty ☠ 08/22/2017 at 16:020 Comments

Hopefully this version fixes the voltage supply to the LNA controls by incorporating a simple voltage divider to get exactly 2.5 volts onto the chip. Eventually I should find the one resister to do the job as this will save power, but this is not important at the moment.

I've also added the option to use a RSSI on the phone Tx, just after the band pass filter, which can be used, amongst other things, to confirm that there is a compatible cell phone in the near vicinity. If the phone is detected, it can illuminate one of the spare LEDs to re-assure the user that there is some functionality. The RSSI is connected to the main RF line via a small coupler chip.

I've also got rid of the toggle switch on the power line and replaced it with a more compact slider switch and put it in the correct position, not way off at the top right hand corner. Hopefully this version will be free of any critical errors.