Understanding Triplexers: Basics and Differences

This page describes triplexer basics, including its definition, and highlights the difference between diplexers and triplexers. A list of popular triplexer vendors with their key features is also provided.

Introduction

We’ve seen multiplexers, which multiplex or route multiple signals from their input ports to a single output port based on selection lines. Demultiplexers perform the reverse operation, routing input data to one of its output ports based on selection lines. Diplexers and triplexers function similarly to multiplexers but are designed differently. Multiplexers use separate feed points with individual paths at the input. Diplexers and triplexers use a common feed point with separate filters to combine or split signals while maintaining good isolation between paths.

What is a Triplexer?

Definition:

A triplexer is a device with three input ports and one output port, as shown in the figure above. An RF triplexer operates at radio frequencies and is commonly used in wireless communication systems, including radar.

Other similar devices include diplexers, quadplexers, and quintplexers. They share similar construction and operation, differing primarily in the number of input ports. A triplexer allows the combination and separation of signals in multiple wireless bands. Figure 2 depicts its use in the design of a Distributed Antenna System (DAS), where the system combines nine inputs to three distributed antenna feeds.

Triplexers are usually designed using passive techniques to minimize size and cost. They offer good isolation between ports and minimal insertion loss over individual paths, as well as good return loss at all input and output ports.

Difference between Diplexer and Triplexer

The following points summarize the key differences between diplexers and triplexers:

• Diplexer: Has two input ports and one output port. It’s used to share a single antenna between a transmitter and a receiver or to enable the use of a single RF antenna between two transmitters. Diplexers separate bands, whereas duplexers separate transmit and receive frequencies within the same band. Diplexers use filters to separate bands and offer low Passive Intermodulation (PIM), unlike duplexers. Refer to the difference between Diplexer vs Duplexer for more information.
• Triplexer: Has three input ports and one output port. It is used for many applications such as power combiners and power dividers. Similar to diplexers, triplexers can connect three transmitters or three receivers to a single RF antenna.

Triplexer Vendors

The following table lists popular triplexer vendors with their respective features, helping users choose the right triplexer for their needs.

| • One such Triplexer operates in frequency range from 820 to 2170 MHz.