DUPLEXER，雙工器是異頻雙工電臺，中繼台的主要配件，其作用是將發射和接收訊號相隔離，保證接收和發射都能同時正常工作。它是由兩組不同頻率的阻帶濾波器組成，避免本機發射信號傳輸到接收機。

Duplexer, the duplexer is the main accessory of different frequency duplex radio and repeater. Its function is to isolate the transmitting and receiving signals to ensure that the receiving and transmitting can work normally at the same time. It is composed of two sets of stop-band filters with different frequencies to prevent the transmitter from transmitting to the receiver.

雙向器是一種通訊系統元件，用來區隔在同一傳輸路徑上的發射和接放訊號,一般具有三個埠，在不同的應用可以由不同的元件所構成。雙向器品質決定於插入損耗及收發端隔離度，高損耗會降低系統性能，而低隔離度則可能造成接收機承受過大的發射訊號，造成元件損壞。

A bidirectional device is a communication system component used to separate the transmit and receive signals on the same transmission path. Generally, it has three ports, which can be composed of different components in different applications. The quality of the bidirectional device is determined by the insertion loss and the isolation of the transceiver. High loss will reduce system performance, while low isolation may cause the receiver to withstand excessive transmit signals, resulting in component damage.

另外要特別注意的是，雙向器(Duplexer)基本上是雙工器(Diplexer)的一種，而兩者的區別在於雙工器的三個埠不一定是通道、上行、下行的組合，有可能是用來讓兩個上行或兩個下行共享傳輸路徑。

In addition, it should be noted that a duplexer is basically a type of duplexer, and the difference between the two is that the three ports of the duplexer are not necessarily a combination of channel, uplink, and downlink. It may be It is used to allow two uplinks or two downlinks to share the transmission path.

三工器是一種 4 端口濾波設備，可將一個輸入分成三個不同的輸出，每個輸出具有不同的頻率。它也可以反過來使用，將三個不同頻率的信號路由到一個端口。三工器使單根同軸電纜能夠進入三個不同天線的饋電。這種雙向設備通常由 3 個具有不同通帶頻率的帶通濾波器組成。

A triplexer is a 4-port filtering device that splits one input in to three different outputs each with a different frequency. It can also be used the other way round and where it routes signals at three different frequencies to a single port. A triplexer enables a single co-axial cable to run into the feed of three different antennas. This bi-directional device usually consists of 3 bandpass filters with different passband frequencies. 

四工器是一種 5 端口濾波設備，可將一個輸入分成四個不同的輸出，每個輸出具有不同的頻率。它也可以反過來使用，將四個不同頻率的信號路由到一個端口。四工器使單根同軸電纜能夠接入四個不同天線的饋源。

A quadplexer is a 5-port filtering device that splits one input in to four different outputs, each with a different frequency. It can also be used the other way round and where it routes signals at four different frequencies to a single port. A quadplexer enables a single co-axial cable to run into the feed of four different antennas.