An Ultra Low Passive Inter-Modulation (PIM) Diplexer

Passive Intermodulation (PIM) is a phenomenon which results from non-linear voltage/current behavior. PIM is generated when two or more frequencies interact within a non-linear component or structure. Magnetic materials, oxidized contacts, or even dissimilar base metals in the signal path can cause PIM. The resulting intermodulation products are at different frequencies from the original signals and have the potential to degrade communication systems. Advanced communication satellites with multiple payloads are susceptible to PIM interference to the communication systems. Especially vulnerable to PIM effects are receivers co-located with high power transmitters. This is a common scenario of communication satellites for mobile systems, such as the Mobile Users Objective System (MUOS), which require a high power transmitter and a sensitive receiver. The critical component at the intersection between the high power transmitter and sensitive receiver sections of a communications system is the diplexer. The diplexer must effectively isolate the high power transmit signals from the receiver. PIM generated within the diplexer has the distinct potential to seriously degrade a communications channel. As an engineering and products company with a demonstrated expertise in communications, NuWaves-Ltd. proposes to apply our extensive experience base involving high performance diplexers to this communications challenge.