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.
The design files (including schematics + layout) are kept at https://cgit.osmocom.org/osmo-bts-amp/ .
Schema can be seen here, pdf rendering available as osmo-bts-lna_schematic.pdf, too.
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, -70dBm input:
Osmo-BTS-LNA, -90dBm input:
Osmo-BTS-LNA, -110dBm input:
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.