Removed from Anritsu RF test equipment, all cells completely operational prior to dismantling of the equipment (obsoleted)
Anritsu RF Attenuator
Programmable steps
Part #: 339H28022A
The following basic specifications come from the package markings and previous equipment specifications
I do not have any technical information from Anritsu directly
Nominal impedance: 50 Ohm
Power handling: 50W
SMA Female & N Type Male (Silver plated)
Physical size: (module body not including the connectors) 62mm x 28mm x 32mm
Weight: 200g
Useable to at least 2Ghz
Programmable attenuation from 0 to 50dB via the 3 external ports, these being marked as 20dB 10dB & 20dB. Enabling these in combinations will provide attenuation in 10dB steps.
Device technology is PIN diodes, no mechanical switching is used.
Here is a link to some interesting technical information about the use of PIN diodes in RF switching/attenuation https://www.digikey.com/en/articles/how-and-why-to-use-pin-diodes-for-rf-switching
This attenuator came from the Anritsu MD1623B PCD Signalling Tester - equipment designed to receive and transmit signals in the 800Mhz & 1.8Ghz frequency bands (2G cellular communications)
Previously PCB mounted on the RF Attenuator/Reverse Power Protection board 322U34201a (see my note below about this board)
Transmitter power output of this equipment is up to 50W RF
Each port attenuation function is clearly indicated on the solid aluminium metal block packaging
Control of each port appears to be +/- 50VDC
TECHNICAL OBSERVATIONS:
I had a close look inside the module but I cannot identify the PIN diodes used, the top of the device is blank and in fact there are very few markings on this board, the only components I can see clearly are a number of SMD resistors.
I NO LONGER have the original "control" PCB (322U34201a) as it was supplied with the other attenuator I had so the user will need to sort out the control signals to this attenuator.
Background info on the 322U3421a board:
Mounted on the board is only one active device, an NEC uPA2981C (18 pin DIL). This is an integrated circuit containing 8x source drivers but only 6 are being used (this PCB was originally driving 2x attenuator modules - one attenuator was controlling the RF input and the other attenuator controlling the RF output)
The board indicated that 16V DC is the supply rail for the uPA2981C (pin 9) - there is simple DC filtering onboard and nothing else, very simple electronics.
The inputs to the uPA2981C were under the control of another card in the system.
I have taken a photograph of the uPA2981C device specifications, in particular the voltage/current characteristics of those inputs and outputs.
COSMETIC CONDITION: Excellent
TESTING: The attenuator module is known to be fully operational prior to removal from the Anritsu test equipment (equipment obsoleted due to proprietary 2G cellular technology)
