Tri-Band transceiver

[ctzof]

Hello,

I am trying to make a new design where I want to receive a signal in three different band and fed them to a SDR radio platform. The three bands are

I: 868-868,6 MHz
II: 902-928 MHz
III: 2,4-2,85 GHz

One possible way is to have three band pass filters in the transceiver and then combine all these signals together. All bands belong to ISM region so its easy to find SAW filters in the market for these bands. What is the best way to combine these signals if I follow these procedure? I suppose something like a 3way combine-splitter. Can you suggest anything?

Another way could be a multiband filter but I am not really sure about that and how possible is to build a structure like that.

Does anyone have any suggestion for a design like this?

 

[BigBoss]

Triplexers for these three band should be existing in the market.( I'm not sure).But 3 bandpass filter then a simple combiner will also serve.
Using switches ( SPDT3 ) can also be used if the transceiver won't work at these three frequencies simultaneously...

 

[ctzof]

Triplexers for these three band should be existing in the market.( I'm not sure).But 3 bandpass filter then a simple combiner will also serve.
Using switches ( SPDT3 ) can also be used if the transceiver won't work at these three frequencies simultaneously...

Do you know any of these triplexers that would be ideal. Also I found these combiner from minicircuits **broken link removed** but is a 4-way. Is it possible to isolate one of its ports to reduce the total loss on the other 3 ports?

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Do you know any of these triplexers that would be ideal. Also I found these combiner from minicircuits **broken link removed** but is a 4-way. Is it possible to isolate one of its ports to reduce the total loss on the other 3 ports?

Regarding your question I want to use the three bands simultaneously.

 

[BigBoss]

Do you know any of these triplexers that would be ideal. Also I found these combiner from minicircuits **broken link removed** but is a 4-way. Is it possible to isolate one of its ports to reduce the total loss on the other 3 ports?

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Regarding your question I want to use the three bands simultaneously.

You cannot decrease the insertion loss by terminating the 4th port.It's essentially a power combiner/splitter and it doens't have any filtering function.Therefore it does not fit to your requirements.

 

[ctzof]

You cannot decrease the insertion loss by terminating the 4th port.It's essentially a power combiner/splitter and it doens't have any filtering function.Therefore it does not fit to your requirements.

Yes I know that it doesn't have any filtering function but I am going to use saw filters for the filtering as I have said int the initial post. Is it possible to implement a 3-way power combiner for this desired frequency range? A triplexer would be an ideal solution but I cant find something for these frequencies in the market.

 

[BigBoss]

Yes I know that it doesn't have any filtering function but I am going to use saw filters for the filtering as I have said int the initial post. Is it possible to implement a 3-way power combiner for this desired frequency range? A triplexer would be an ideal solution but I cant find something for these frequencies in the market.

It's surely possible to design a wideband power combiner or you can also buy a 3 way power splitter/combiner if you're OK at least 4.7dB branch loss.

 

[tony_lth]

using two diplexer seriesing to solve your issue.