HP-Agilent/Keysight 11757B

The 11757B characterizes the equalizers in modern digital microwave radios by introducing a precisely-controlled notch in and around the radio’s transmission bandwidth. This allows precise measurements of the equalizers’ ability to compensate for multipath fading. Testing susceptibility to multipath conditions is especially important since fading is recognized as one of the predominant causes of unacceptable bit error rate and link outages. The 11757B offers accurate, economical multipath testing and records measurements automatically on a built-in printer. The 11757B brings accurate, economical multipath fade testing to digital microwave radio. Now with built-in signature measurements, tests once confined to the laboratory can be made and recorded quickly in manufacturing and even at the radio site. Testing susceptibility to multipath conditions is especially important since fading is recognized as one of the predominant causes of unacceptable bit error rate and link outages. As digital microwave radios move to increasingly complex modulations, such as 64 and 256 QAM, the need for multipath fade testing becomes even more crucial to working microwave communication systems. Waiting for a natural multipath fade is impractical in the field and impossible in the lab. Yet a radio’s adaptive equalizers are not exercised unless the received signal has experienced some propagation distortion. The 11757B simulates a simplified 3-ray model of both static and dynamic multipath fades by introducing a precisely controlled notch in or around the transmission bandwidth. This allows precise measurements of the equalizers’ ability to compensate for such distortions. The 11757B has built-in M-Curve signature capability. An important bottom line test of a radio’s multipath fading protective systems, these signatures show the range of acceptable radio performance with and without multipath protection. By stressing the radio’s equalizers with controlled amounts of multipath fade and monitoring the radio’s bit error rate, the 11757B automatically measures and records a radio’s signature on a builtin printer. These signatures are useful for comparing different radios or characterizing individual radio performance. • Automatic multipath signature measurements • Measures and prints static M-curves, dynamic M- and S-curves, recovery signatures, recovery times, and dispersive fade margin • High-performance, lightweight, and economical