Osmo-bts-lna » History » Revision 7
Revision 6 (laforge, 10/07/2018 06:42 AM) → Revision 7/10 (mschramm, 01/16/2019 04:35 PM)
h1. osmo-bts-lna
{{>toc}}
The Osmo-BTS-LNA is a low noise amplifier intended for DCS uplink reception (MS->BTS). This is DCS1800 for GSM and band 3 for both UMTS and LTE.
The LNA features a 2-stage LNA formed by RF3865 (RFDM/Qorvo) and two EPCOS B3832 SAW.
The board consumes about 200mA @5V. It intregrates a MIC5219-5 LDO and should be supplied with 5.5-12V DC (7V nom.), either
* by local connection (DC input), or
* by 'phantom power' via DC biasing from the RF output.
The RF port can be used with U.FL/IPEX or SMA by moving a coupling capacitor. Bias sourcing is available via SMA.
h1. Schematics
The design files (including schematics + layout) are kept at https://cgit.osmocom.org/osmo-bts-amp/ . FIXME
You can find a JPG rendering here for your convenience. PDF files are attached to the bottom of this wiki page, too.
!{width: 60%}osmo-bts-lna_schema.jpg!
h1. Photos
!{width: 40%}bts-lna-top_mr.jpg!
!{width: 40%}bts-lna-top-2_mr.jpg!
!{width: 40%}bts-lna-top-app_mr.jpg!
!{width: 40%}bts-lna-bott_mr.jpg!
h1. RF measurements
The Osmo-BTS-LNA has been tested on an Agilent E8356A. Some performance curves can be seen below. Input signal attnuation was -40, -70, -90 and -110 dBm.
*Osmo-BTS-LNA, -40dBm input*:
!osmo-bts-lna_-40db-in.png!
*Osmo-BTS-LNA, -70dBm input*:
!osmo-bts-lna_-70db-in.png!
*Osmo-BTS-LNA, -90dBm input*:
!osmo-bts-lna_-90db-in.png!
*Osmo-BTS-LNA, -110dBm input*:
!osmo-bts-lna_-110db-in.png!
h1. Availability
An 1800 MHz version of osmo-bts-lna can be obtained from http://shop.sysmocom.de/products/osmo-bts-lna-1800
Swapping the filters would permit to change this to other bands, as needed.
