A microwave and RF multiplexer is a multi-channelmodule combining several filters to a common port,usually the antenna port. Its block diagram consists oftwo parts: a distribution system, called the manifold,and a group of filters, which may include lowpass,highpass, bandpass, and bandstop. A multiplexer mustfulfill two main requirements.
- Broadband (can be wider than a decade)
- Pseudo-elliptic transfer functions
- Printed circuit, therefore excellent reproducibility
- Individual highpass/lowpass diplexers can be cascaded to make n-channel multiplexers
- All complexity is confined to printed circuit board and milled housing (CNC machines)