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Question on TX/RX antenna ports

Jim Kusznir <jkusznir@...>
 

Hi all:

I have a quick question on the implementation of the separate TX and RX ports on the UDRX:  I realize its half-duplex, so will there still be T/R switching internally to protect against tx rf coming back on the rx port?

My application is for a mountain application where a circulator is required on the tx output.  Typically for these radios, I mod them to intercept the TX path prior to the T/R switch and break them out to the circulator/bandpass cavity, then back in.  I then use the T/R switch and its single antenna connector to connect to the input antenna (which is used both for RX and TX).

So, in the case of the UDR with separate TX/RX ports, would I be able to simply split the incoming antenna and run it into the RX port directly, and take the other side and run it through the circulator/band pass filter?  Or will there be an output to drive an external T/R switch?  How would you recommend me using it in that configuration?

Thanks!
--Jim

Bryan Hoyer <bhhoyer@...>
 

Jim,

I'm just wrapping up some time critical engineering work.

First of next week, I'll publish the block diagram of our antenna switch with both options and then I can address your question better.

Thanks,
Bryan

On Jan 23, 2014, at 10:20 AM, Jim Kusznir <jkusznir@...> wrote:


Hi all:

I have a quick question on the implementation of the separate TX and RX ports on the UDRX:  I realize its half-duplex, so will there still be T/R switching internally to protect against tx rf coming back on the rx port?

My application is for a mountain application where a circulator is required on the tx output.  Typically for these radios, I mod them to intercept the TX path prior to the T/R switch and break them out to the circulator/bandpass cavity, then back in.  I then use the T/R switch and its single antenna connector to connect to the input antenna (which is used both for RX and TX).

So, in the case of the UDR with separate TX/RX ports, would I be able to simply split the incoming antenna and run it into the RX port directly, and take the other side and run it through the circulator/band pass filter?  Or will there be an output to drive an external T/R switch?  How would you recommend me using it in that configuration?

Thanks!
--Jim


Keith Goobie <keith@...>
 



Sent from my iPhone

On Jan 23, 2014, at 1:46 PM, Bryan Hoyer <bhhoyer@...> wrote:

Jim,

I'm just wrapping up some time critical engineering work.

First of next week, I'll publish the block diagram of our antenna switch with both options and then I can address your question better.

Thanks,
Bryan

On Jan 23, 2014, at 10:20 AM, Jim Kusznir <jkusznir@...> wrote:


Hi all:

I have a quick question on the implementation of the separate TX and RX ports on the UDRX:  I realize its half-duplex, so will there still be T/R switching internally to protect against tx rf coming back on the rx port?

My application is for a mountain application where a circulator is required on the tx output.  Typically for these radios, I mod them to intercept the TX path prior to the T/R switch and break them out to the circulator/bandpass cavity, then back in.  I then use the T/R switch and its single antenna connector to connect to the input antenna (which is used both for RX and TX).

So, in the case of the UDR with separate TX/RX ports, would I be able to simply split the incoming antenna and run it into the RX port directly, and take the other side and run it through the circulator/band pass filter?  Or will there be an output to drive an external T/R switch?  How would you recommend me using it in that configuration?

Thanks!
--Jim


bhhoyer@...
 

Jim,


I reviewed our setup and it requires an external switch to protect the receive port and yes the Tx/Rx signal is available to drive it.


Please send me a block diagram of the application. I may be able to make a slight change and use the internal switch.


Bryan

Jim Kusznir <jkusznir@...>
 

Ack, this message got mis-filed by my mail client, sorry for the delay!

Here's my attempt at a block diagram...I'm pretty poor at diagramming...

This is what my current Mitrek on the hill is configured as.  Simple intercept of the TX line to the TX/RX switch.  It breaks that out externally for isolator support, then brings it back into the box and uses the stock TX/RX relay for switching.

For my purposes, it would be great if I could get a "standard" UDR, except there are two additional connectors on it (SMA is fine :) ), that breaks out the TX path (and if desired, the radio can ship with a jumper across these two ports such that it functions identically to a stock UDR).  For those users who want to use seperate TX and RX antennas, I think they could just use the TX out and not send it back into the radio for their TX output, and use the "normal" antenna port for RX.  That way the receiver is still protected against too much RF on transmit.

Anyway, thanks for your response!  My Mitrek on the hill isn't doing so well now, so I'm leaning more and more toward replacing it with a UDR as soon as I can get one (originally I was just going to get one for personal use).


On Tue, Jan 28, 2014 at 1:31 PM, <bhhoyer@...> wrote:
 

Jim,


I reviewed our setup and it requires an external switch to protect the receive port and yes the Tx/Rx signal is available to drive it.


Please send me a block diagram of the application. I may be able to make a slight change and use the internal switch.


Bryan