Above:Noise Figure and Gain measurements indoors (22 C temperature).


Many friends were asking  me to prepare  a smaller version of the PGA-103+ mast-head LNA I have made as described in another page of this website, mostly in order to replace older LNAs. One of them needed an amplifier for RFI investigation of his product using an old spectrum analyzer without a preamplifier. 

On that period, Christophe, F1JKY, president of the Amateur Radio Association of Dauphine in France,  was looking for an inexpensive way to produce his design of a PGA-103+ LNA in a small PCB too, so we finally end up making together a small production using one good factory in China. The major concern was to maintain Christophe's original specifications of his older LNA.

The result is very good. It is a nice broadband LNA with minimal Noise Figure. The PGA-103+ chip is produced by Mini-Circuits and it is a modern, new generation  ultra-linear low-noise monolithic  amplifier with ultra high IP3, high dynamic range and high output power plus very low noise figure. Its performance as an LNA for our amateur applications is excellent. This amplifier chip has quickly become very popular to hams around the world because of the simplicity of the design effort and its capability of similar repeated results. Christophe has optimized his design by working the chip at 3.6V to ensure the highest dynamic range and linearity at the lowest noise figure possible.

The gain of the amplifier as specified in the datasheet is not constant over frequency. While its gain is more than 20 dB at 400 MHZ, on 4 GHZ is specified to be only 6 dB. This is not so much of importance for ham radio applications if we know it before starting a new design for a receiver for example. As explained in my article for the antenna mast-mount version, the Noise Figure is what concerns us mostly as LNA's Noise Figure dominates system's Noise Figure. 

The PCB dimensions are 34 x 34 mm and it fits into a readily available metal enclosure (Schubert 37x37x30 mm). A 1000 pF feed-through type capacitor can be used to supply +12 VDC to the pad that connects to LL4001 diode's anode terminal. Adding a small ferrite bead is also a good practice.  Christoph suggests to solder the enclosure walls onto the SMA connectors bodies and this way to completely shield the enclosure.

His original realization is described here:


and this webpage includes measurements of the amplifier's compression point, gain curve, IP3 and NF. 

The Amateur Radio Association of Dauphine's website address is http://f1jky.fr

ORDERS for a complete PCB Module (EUR 23.35) 

The Module includes a  high-quality ENIG 0.8mm with 1 oz gold over nickel over copper FR4 PCB (34 x 34 mm) that comes with all SMD components factory pre-soldered. RF capacitors are used for all the circuits.  A High Q, high current inductor is used in the Bias-Tee section.

Two SMA female connectors are also supplied unsoldered. A short 1 mm trim  is needed on the central pins for not exceeding the pcb pads as you can check before soldering. Also, a small cut is needed on one of the top side -lower grounding legs of the SMA connector so it will not disturb the input diode (for the input connector) and the decoupling caps (for the output connector). The DC current is 70 -100 mA at 12VDC, while 9-15V can be applied.

The shipping is with registered mail  (your signature is required upon delivery). 

We usually ship the next day and it takes about a week to 10 days for USA or Australia, less than a week for Europe.​

If you want to order from France, check with Christophe , F1JKY  as he can offer better price on shipping:
Web Site of ARRAD ( Association of the Radio - Amateurs Relays of the Dauphine ) : http://www.arrad38.fr

​The prices do not include 24% Greek VAT applicable only to individual buyers from European Union. 

PGA-103+ LNA

With input overload protection diode (BAV99)

9-12VDC supply with inverse polarity protection

5V Low Drop Voltage Regulator on board

Fits inside a Schubert 37x37x30 tin box.