Antenna Diversity vs True Diversity

Basically, an antenna diversity system is a non-diversity system. The two signals that come in from the two antennas are compared and switched via a simple comparator circuit and the resultant signal is fed into the non-diversity RF circuit for further processing. The rest is non-diversity.

In a true diversity system, two separate tuners processed the two incoming radio signals till the detector circuit before making a comparison by a diversity circuit. It is a much complexed and accurate circuit as compare to that of antenna switching system. True diversity system has a much higher sensitivity than the antenna switching system.

This is where diversity reception comes in to its own. Diversity reception is basically the use of two antennas, which simultaneously poll the incoming transmitter signal and combine to provide an uninterrupted signal to the receiver. The chances of experiencing signal drop-out are 5 times less using diversity reception than they are with single antenna systems. Further, by increasing the signal strength by 10dB, the improvement is a factor of 45 times. Therefore, with a diversity system, neither signal drop-out or noise will be problems over normal transmission distances. based on this principle, a diversity system is a must for applications that require guaranteed professional audio performance.

Similarly, where longer distance transmission is required, diversity reception offers a much greater chance of the receiver providing a clean output. Wireless microphones are not two-way radios or walkie-talkies of course, but satisfactory long distance transmission can be achieved if diversity reception and the right antenna configuration are used.

Many users do not realize that single antenna systems can be subject to dead spots in their pick-up pattern. This is because the transmitter signal arriving at the receiver antenna is actually a combination of several signals, some direct (from the transmitter) and some reflected (off walls for example). If these signals arrive at the receiver antenna in an out-of-phase condition, then they can combine to cancel each other, causing a signal drop-out as a result. Of course, the closer the transmitter is to the receiver, the less frequent dead spots or dropouts will be. So, many manufacturers offer single antenna, non-diversity systems for entry level, non professional use – applications where transmission distances are short and some signal drop-out can be tolerated. The MR-823 is designed for the entry-level market where a non-diversity receiving mode is acceptable. The MR823 is ideal for short-distance Karaoke shops, but NOT applications on the professional stage, difficult environments or for long-distance transmissions. Users should choose a receiver with dual-antenna "diversity" receiving operation (e.g. MR-801 or similar) for these professional and critical applications.