Can I attenuate the receive antenna to reject interference?

Question

I have a 500-600Mhz wireless system for instruments on stage. I use 2 directional antennas to pick up the transmitters on stage. I like using the directional antennas for obvious reasons. The wireless packs are transmitting in the milliwatt range.

But the problem is that the receive antennas have a higher gain and are directional...so they pick up unwanted signals that are NOT on the stage. Can I put a an attenuator on the receive antenna to cut down the range of the directional receive antenna? This way I keep the direction properties of the antenna, but I only pick up what is on, or close to the stage....thanks for any input!

Answer 1

You confuse or fool by the system that you have. Receiver antenna usually is designed for non-directional and transmitter antenna is designed for directional. For frequency 500-600mhz (UHF), it still requires couple of miles away before seeing the directional effect. From the stage to your receiver only within less than 100 feet. therefore no such effect existed except it only blocks the signal sends away at the back (most signal send 180 degree in front of stage).Since you mention the transmitter signal strength is in millewatt, the noise problem can only be overcome by increasing the transmitter power if your system has this selection,or move the reciever antenna more close to the transmitter antenna. Then the signal that you want shall overcome the unwanted signal.

Answer 2

There is an inherent anomaly in the statement "... antennas... are directional... so they pick up unwanted signals that are NOT on the stage."

What? Directivity is good here. An omnidirectional antenna would pick up signals from all over the place -- a directional antenna is exactly what you need to acquire the signal you want and exclude signals from other directions.

Your receive antennas should be off-stage and oriented to acquire max signal from the mikes. Use the directivity of the RX antennas to maximize your signal/noise ratio. An attenuator cannot do that.

Answer 3

try it. Attenuators are cheap. But an attenuator will reduce the wanted signal as well as the unwanted signal.

Attenuators do not reduce the range, they reduce the signal. All signals.