Low Noise Block Downconverter for a Commercial Satellite Broadcast Network
Problem
A major satellite broadcast network had to upgrade their receive system in order to support the increased data rate and throughput from the satellite transponders. Commercially available low noise block downconverters (LNBs) could not meet the more stringent noise figure, phase noise and input match requirements. Existing suppliers, geared for extremely high volume production quantities, were unwilling or unable to produce a custom design meeting the tougher specifications.
Solution
By working closely with the customer, CAP Wireless developed a high performance isolated LNB. The result was a unit with extremely low noise temperature, typically less than 30°K. It also has excellent phase noise, typically -90dBc/Hz @10KHz offset, and incorporates integrated lightning protection. The unit includes an input isolator and its inherently high out-of-band rejection makes it less susceptible to interferers that potentially degrade the signal-to-noise ratio (SNR). All of this results in data rates that are significantly higher than the commercially available products previously used for the system.
CAP model CA251100 met or exceeded all performance parameters, it improved Eb/No performance, and enabled the customer to improve their throughput from 54 MBits to 73 MBits. The 35% improvement in data rate from existing satellites easily justified the increased cost of the CAP LNB compared with the commercially available products.
Over 200 affiliate stations have installed the CAP Wireless LNBs and are now experiencing significantly improved performance.
