Electronics > RF, Microwave, Ham Radio

Look what the cat dragged home: Phase Atlantic microwave amp (?)

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wkb:
Recently acquired at a hamfest. I was attracted by the nice milled aluminium box with goldplated SMA connectors, terminated with 50R SMA terminators.

The single SMA is labeled RX_IN, the 4 SMA on the right are labeled LNA.  The 2 grey devices are Anaren microwave directional couplers.
I can identify some power regulator chips.  Plus (?) MMIC or GaAs devices(?).

Anyone recognise this one?

Wilko



PE1RKI:
no mmic's, all gaas fets, the big ones are some kind of mgf1801 types.
i have several boards that look like this but are made for the 900mhz band and the big fets do 300+mW on 10ghz if properly tuned and on a custom pcb.

German_EE:
Working from left to right the signal comes in and is filtered, it then passes through two MMIC amplifier stages before hitting the main power amplifier assembly. The main power amplifier uses 2 x 90 degree hybrids and two more higher power amplifier chips (the yellow devices), it's done like this to improve transmit IMD and ensure a 50 ohm impedance on both the amplifier input and output. Finally the amplified signal is split into four using three 180 degree hybrids.

The circuits at the bottom are either for bias or transmit/receive switching.

KJDS:
That's a cellphone basestation receive amplifier with four outputs. Noise figure should be sub 1dB, and possibly better. The input stage will need to be pHEMT to meet a basestation spec.

wkb:
A couple of detail pictures. Maybe that helps.  The big FETs(?) look like ceramic material, maybe BeO(?), topped with a gold plated cap.

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