The need of duplexer in low power operation

Alexander Chemeris alexander.chemeris at
Thu Oct 11 10:21:54 UTC 2012

On Thu, Oct 11, 2012 at 9:58 AM, Sylvain Munaut <246tnt at> wrote:
> Hi,
>> IIRC, both nanoBTS and SysmoBTS have separate antennas for Rx andTx and do
>> not use duplexers. Do we need duplexer for UmTRXv2 if it operates in the low
>> power mode, without an additional PA/LNA?
> Note that both still have internal filters.

You mean bandpass filters? Are they only on Rx side or both Tx and Rx?

> Antenna design also plays a role. The nanoBTS uses patch antenna
> separated by a lump of metal to minimize direct radiation from TX to
> RX.

Yes, I remember that nanoBTS has patch antennas for better isolation.
But IIRC sysmoBTS has rubber duck antennas which made me wonder how do
they do Tx/Rx isolation.

Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио

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