Exact item shown, lumped element type coupler

This is a professionally‑built 2‑way RF power splitter/combiner, engraved “450288‑33, S/N 2” on the top plate. The construction is not hobbyist—inside is a well‑executed RF network using ferrite toroidal inductors, resistive elements, and a cleanly machined cavity. The covers are factory‑glued, not screwed, which is typical of tuned, low‑volume engineering or program hardware.

It has three SMA‑female ports: one input (the center one, marked "S") and two output/combiner ports.

I tested the device on two different VNAs. The first set is using a 1 channel VNA, so you can see the two channels and how they behave, and the second set are with a single channel VNA that I thought would be more accurate, but instead it's giving me a lot of ripple.  Both analyzers are 3 GHz units  Plots are included for both outputs. I don't know if the "notch" in port 2 was by design or just not important because it is out of band

Measured examples (from included plots):

• Insertion loss per output around −3.x dB (−3 dB + IL), about 1/2 dBc at 500 MHz, it's rising ar around 1 GHz it's at .8 dBc
• Outputs track closely (dual‑trace for A/B comparison included)
• S‑parameters shown up to 3 GHz on a dual‑trace analyzer and a single trace analyzer