A new 4-antennas FM diversity system was designed and built. The new system utilizes a 2-antennas combining system, fast distortion detector, and ultrasonic noise detector. Hence, it has three modes of operation. The basic operation of the system is to select the two least distorted antennas for the combining system to add them in phase. In weak signal areas it uses the ultrasonic noise detector to find the least distorted antenna. In good signal conditions, it can either be in switched antenna mode (long delay multi-path) or phase combine mode (short delay multi-path). To test the above system in lab, a 4-antennas Diversity Testing System (DTS) was implemented to record FM data in the field. The recorded data can be regenerated in the lab for diversity systems testing.     «

A new 4-antennas FM diversity system was designed and built. The new system utilizes a 2-antennas combining system, fast distortion detector, and ultrasonic noise detector. Hence, it has three modes of operation. The basic operation of the system is to select the two least distorted antennas for the combining system to add them in phase. In weak signal areas it uses the ultrasonic noise detector to find the least distorted antenna. In good signal conditions, it can either be in switched antenna...     »