/Manuals/Built/LNA/NBLNA-70cm.docx
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Rev. A 8/10/2022
DEM NBLNA70cm
428-438 MHz.
Specifications:
Gain:
18dB nominal in band
Noise Figure:
<0.5dB Nominal
P1dB:
+21dBm output
Input VSWR:
>12dB
Output VSWR:
>6dB @ Design Frequency
Voltage:
+7 - +22 VDC
Current Drain
70mA nominal
Description:
Our new NBLNA-70cM
N
arrow
B
and 70 Centimeter LNA low noise amplifier shares a
common design that is utilized by all LNA’s between 144 and 1300 MHz. Each LNA utilizes the
ultra low noise QORVO QPL9547 MMMIC coupled with the latest in SAW filter technology
optimized to the specific frequency band of operation. This new design technology produces a
LNA that is more selective and more robust in reducing out of band interference.
This new design employs a higher linear output active device that exceeds all other DEMI
LNA products. Because of this, the filtering is on the output circuit. The NBLNA is housed in a
1.75" L x 1" square machined enclosure. Only the difference in connector selection will alter the
length measurement. Any combination of Type "N", BNC or SMA connectors is provided as
ordered.
This new LNA design is a Receive only device and does not offer any RF bypass switching
for transceiver operation. This LNA is ready
to be “dropped in” to any pre-existing receive system
or to be a component in a newly developed receive system.
Installation and Operation:
Depending on your application, the LNA may be installed anywhere in your system to
increase gain. To maintain or improve the systems noise figure requires the LNA to be installed as
close to the systems antenna as possible. If you plan to utilize this LNA in a transceiver system
with transmit bypass relays, be sure of their isolation characteristics and transmit power handling
capabilities before transmitting. Use only interconnecting cables and/or adapters that are rated for
use at or above the intended frequency of use. Inadequate cabling or cables with poor shielding
may cause system instabilities, signal loss, or undesirable intermittent operation. Test any
sequenced scheme before applying transmit power to avoid mishaps.
The connector marked
INPUT,
is to be connected to the antenna side of the system. The
OUTPUT
is connected to the receiver side of the system. Expected performance with the LNA
correctly installed should be overall improvement in gain and system noise figure of the receive
system. The proper installation of an LNA becomes more important if you make this installation in
a harsh RF environment. The gain bandwidth of the LNA is wide and depends on the filter for the
operating frequency to obtain a low noise figure. This may result in the passing of strong but very
close in frequency out of band signals that may cause the overloading of your receiver resulting in
increased inter-modulation. With any receive installation, practice system gain management by not