Mini-Circuits ZFRSC-42-S+ Power Splitter/Combiner

DC to 4200 MHz

See the last two photos for results of measurements of attenuation from the S port to ports 1 and 2 respectively.

low insertion loss, 0.1 dB typ. above 6 dB 
excellent amplitude unbalance, 0.02 dB typ

https://www.minicircuits.com/pdfs/ZFRSC-42+.pdf