Filters/Tuneable Filters

Modern base stations employ multi-function reconfigurable receiver subsystems with broad bandwidth to support multiple frequency bands. High performance tunable filters are needed in these systems. SDP is involved in an ambitious R&D program to develop these Tunable Filters.

Activities involved include:

• Tunable filters with controlled center frequency and bandwidth for WiMax and LTE applications
• Auto-tuning combiners for combining multiple GSM channels with automatic frequency tuning
• Auto-tuning combiners for combing GSM channels and a WCDMA channel, with dynamic center frequencies, to be transmitted on the same antenna

Different Filter technologies and control systems are under development such as:

• Snail shape tuning
• Telescopic cavity with fine-tuning disk
• Cone shaped DR
• DR with dielectric cylinder tuning