Project

General

Profile

Actions

osmo-bts-lna

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.

Schematics

The design files (including schematics + layout) are kept at https://gitea.osmocom.org/cellular-infrastructure/osmo-bts-amp

Schema can be seen here, pdf rendering available as osmo-bts-lna_schematic.pdf, too.

osmo-bts-lna_schema

Photos

osmo-bts-lna, top view
osmo-bts-lna, top view
osmo-bts-lna, w/ SMA edge conn
osmo-bts-lna, bottom view

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

Osmo-BTS-LNA, -70dBm input:

osmo-bts-lna_-70db-in

Osmo-BTS-LNA, -90dBm input:

osmo-bts-lna_-90db-in

Osmo-BTS-LNA, -110dBm input:

osmo-bts-lna_-110db-in

Availability

An 1800 MHz version of osmo-bts-lna can be obtained from https://shop.sysmocom.de/osmo-bts-lna-1800-MHz-band-uplink-LNA-kit/bts-lna-pcba-1800

Swapping the filters would permit to change this to other bands, as needed.

Files (14)
bts-lna_placement-color.jpg View bts-lna_placement-color.jpg 175 KB osmo-bts-lna_placement mschramm, 06/20/2018 08:21 PM
osmo-bts-lna_schema.jpg View osmo-bts-lna_schema.jpg 121 KB osmo-bts-lna_schema mschramm, 06/20/2018 08:21 PM
bts-lna-top-2_mr.jpg View bts-lna-top-2_mr.jpg 110 KB osmo-bts-lna, top view mschramm, 06/20/2018 08:21 PM
bts-lna-top-app_mr.jpg View bts-lna-top-app_mr.jpg 99.9 KB osmo-bts-lna, w/ SMA edge conn mschramm, 06/20/2018 08:21 PM
bts-lna-top_mr.jpg View bts-lna-top_mr.jpg 170 KB osmo-bts-lna, top view mschramm, 06/20/2018 08:21 PM
bts-lna-bott_mr.jpg View bts-lna-bott_mr.jpg 121 KB osmo-bts-lna, bottom view mschramm, 06/20/2018 08:21 PM
osmo-bts-lna_-90db-in.png View osmo-bts-lna_-90db-in.png 10.3 KB osmo-bts-lna_-90db-in mschramm, 06/20/2018 08:21 PM
osmo-bts-lna_-70db-in.png View osmo-bts-lna_-70db-in.png 10.1 KB osmo-bts-lna_-70db-in mschramm, 06/20/2018 08:21 PM
osmo-bts-lna_-40db-in.png View osmo-bts-lna_-40db-in.png 10 KB osmo-bts-lna_-40db-in mschramm, 06/20/2018 08:21 PM
osmo-bts-lna_-110db-in.png View osmo-bts-lna_-110db-in.png 10.6 KB osmo-bts-lna_-110db-in mschramm, 06/20/2018 08:21 PM
EPCOS_B3832.pdf View EPCOS_B3832.pdf 50.8 KB EPCOS_B3832 datasheet mschramm, 06/20/2018 09:05 PM
RF3865.pdf View RF3865.pdf 591 KB RFDM_RF3865 datasheet mschramm, 06/20/2018 09:05 PM
osmo-bts-lna_schematic.pdf View osmo-bts-lna_schematic.pdf 34.8 KB osmo-bts-lna, schematic mschramm, 01/15/2019 05:41 PM
osmo-bts-lna_placement.pdf View osmo-bts-lna_placement.pdf 49.1 KB osmo-bts-lna, part placement on PCBA mschramm, 01/15/2019 05:41 PM

Updated by laforge over 1 year ago · 10 revisions

Add picture from clipboard (Maximum size: 48.8 MB)