I am currently stumped in the design process in creating a method to intercept Bluetooth signals with an antenna and simply outputting the exact signal through another antenna.
I develop Automation scripts for testing Bluetooth between my company's product and cell phones, and I wanted to build a tool that will isolate frequencies of a tester's choosing autonomously.
I thought the best way to accomplish this is a Faraday Cage, in which the phone would be placed inside. I have constructed the cage which effectively blocks all RF signals, including Bluetooth.
It was then suggested to me that I attempt to build a Repeater and place an antenna on the inside and another on the outside; then connect the two through the cage. The two antennas would pass the Bluetooth packets back and forth between the phone and system. I could then sever the connection anytime.
The Actual Question itself
I am having difficulty figuring out an effective way to connect the two antenna together and allowing them to pass the Bluetooth signals back and forth. There seems to be many methods, and I am not the most knowledgeable with RF antennas and such. I thought that perhaps an enlightened individual could give me a push in the right direction so I am not going about a random "witch-hunt" for a solution.
Could someone provide a "top-level" idea? I can do any research necessary to figure out the details.
What I've done so far
I bought two 2.4 GHz duck antennas, a coax cable and some RP-TNC connectors off DigiKey. The impedance of all these are 50 ohm. The connectors are rated for up to 4 GHz. Could it really be as simple as wiring the two antennas together?
I've also been reading data sheets on RF transceivers rated for 2.4 GHz. These interface to an MCU through SPI. These data sheets are easy to follow but I can't imagine that SPI bus is quick enough to transfer every packet, especially when it's clocked in the MHz range. This method also feels like overkill.
The obvious trivial solution here is to have a physical mechanism open and close the cage, allowing the Bluetooth signal to escape. However I am reluctant to do this since I plan on cutting on and enabling the Bluetooth signal hundreds of times a night. Mechanics would be bound to fail. Also I can't create a "Band-pass" filter through this method.
Design ideas for a circuit that captures the 2.4 Ghz (namely Bluetooth) RF signals with antenna and passing the exact signal out another antenna.