Microwave Multiplexer vs. Microwave Diplexer: Key Differences Explained

This article explains the difference between a microwave multiplexer and a microwave diplexer.

Figure 1 depicts a simple multiplexer and demultiplexer.

As shown in the figure, a multiplexer combines multiple input channels (typically low rate) into a single output channel (high rate). At the receiving end, a demultiplexer separates or demultiplexes these same channels. There are various multiplexing techniques, such as Frequency Division Multiplexing (FDM) and Time Division Multiplexing (TDM).

Microwave diplexers and microwave multiplexers filter out and separate multiple frequency channels or bands within a common transmission line. This directs each channel to its appropriate output port. In the reverse direction, these systems can combine signals of different frequencies from separate input channels into a single output port. Both microwave multiplexers and diplexers are essential when transmitting multiple different frequency signals through a single transmission medium, such as an antenna or transmission line. Signals to be multiplexed are contiguous but should not overlap.

Typically, microwave multiplexers are implemented in circular or rectangular waveguide structures, on PCBs, or as ceramic structures.

Microwave Multiplexer

A microwave multiplexer is a device that multiplexes microwave RF signals. It employs band-pass filters with narrow bandwidth and sharp roll-off specifications in each channel. This filters out the desired frequency components and rejects unwanted out-of-band signals.

Microwave Diplexer

A microwave diplexer is similar to a microwave multiplexer, but it handles only two channels instead of multiple channels. Microwave diplexers are commonly used for separating or combining transmitted and received signals in single-antenna communication or radar systems.

Key Differences Summarized