USB Power Sensors: Single/Multi-Channel Power Measurement
應用說明
Situation Analysis
In many of today’s power measurement applications there is a need to make multiple power measurements simultaneously. Added complexities occur when the measurements need to be obtained from places where access is inconvenient, or when the distance to the measurement location exceeds the IEEE industry-specified USB cable length of 5 meters (16 feet).
For instance, a base station commonly includes a compact equipment shelter or outdoor enclosure panels along with antennas that may be mounted on a roof, the wall of a building, or on a free-standing mast. A given base station may operate several channels (typically two or three), where each channel uses a specific set of frequencies: one for the uplink and one for the downlink. Depending on the communication technique, each channel can simultaneously process communications from one or several active handsets.
These sites require routine maintenance and present several challenges. The distance between the antenna and control room may necessitate that measurements be obtained over distances beyond 5 meters and sometimes as far as 50 meters. Measurements may be required from different power sensors and at hourly, daily or monthly intervals.