antenna switch duplexer diplexer

[hypear]

diplexer signal flow

i am a little confused with antenna switch,duplexer and diplexer.
does anybody know the principle of these,and what's the difference between them
thanks

 

[flatulent]

rat race + duplexers

The switch is a time domain device that connects one transmission line to either of two others but not both at the same time.

Duplexer and diplexer are filters that route signals from one transmission line to either of a set of two lines depending upon the frequency of the signals. This is done with filters.

The two terms are based on the system. If the signal flow is all one way it is a diplexer. If the signal flow is one way for one frequency and the other way for the other frequency it is called duplexer. You can easily remember the difference from the communication term "full duplex" which means transmitting and receiving at the same time.

 

[hypear]

full-duplex diplexer

thanks for your help
so swich is TDD,and the duplexer is FDD right?
in principle,they are all filters,so they should work in the same way.
but in the WCDMA and GSM mobile phone,why should we combine them together?
and do you have any papers about how it works and how to design it
thanks again

 

[flatulent]

diplexer radar duplexer

You are most correct in identifying the switch with TDD and the filters with FDD. There is an economic system tradeoff in deciding between these two basic methods. One example is that TDD can use the same synthesizers in the frequency translation scheme for transmitting and receiving. They stay at the same frequency and so can be designed to optimize phase noise instead of switching speed.

 

[xiajing]

duplex switch radar

the diplexer usually refers to a device as circulator(Rat race)
the duplexer often used as FDD TDD,means you can
speak and listen at the same time.

 

[BrunoK]

diplexer fdd

Just a comment about duplexers. As far as I have understood duplexers, they are ,as mentioned, used to route a signal to different transmission lines. I have an example about duplexers in radar systems. Consider an antenna used in radar system. The system has a transmitter and a receiver. When the antenna transmittes it is important that the receiver is isolated, as the receiver cannot handle the same amount power as the transmitter. When the system is receiving, the transmitter has to be isolated. Here a duplexer is used. It makes sure that the receiver is isolated as long as the system transmitts, and the transmitter is isolated as long as the system receives.

 

[springf2000]

switch is not the TDD, TDD not the switch!
duplex is not all the filter!
in GSM system, the basetion use the cavity filter as the duplex, but at the terminal, use the switch as the duplex, switch is a device, duplex and diplex is a concept!
for example y can use the circulator as the duplex either in the TD-SCDMA system or in the RADAR system!

 

[usman_akramz]

Can any one forward me the research file of the duplexer and diplexer so that one cant be confused?