RF components
How filters, amplifiers, switches, couplers and antennas behave in S-parameters, and what to check on a datasheet.
Each component page starts from the ports and the S-parameters a vendor publishes, then shows which numbers decide whether the part works in a real front end: insertion loss in the band you use, rejection or isolation where the next radio sits, and how the part behaves when it does not see a clean 50 Ω. Datasheet tables give one number per band; the S-parameter file shows the whole curve, including band edges and temperature corners, which is where most surprises come from.
If you are new to the notation, read S11, S21, S12 and S22 explained first, then return loss vs insertion loss. To look at a component file yourself, open it in the free online S2P viewer.
- Duplexer Basics: How Two Filters Share One Antenna2026-10-31A duplexer is a transmit filter and a receive filter joined at a common antenna port. Read insertion loss from S21 or S32 and isolation from S31, where 2 dB of loss passes 63 percent of power.
- RF Test Connectors: SMA, 3.5 mm, 2.92 mm and N Compared2026-11-02SMA is specified to 18 GHz, 3.5 mm to 26.5 GHz and 2.92 mm to 40 GHz, and all three mate with each other. A test chain is only as good as its lowest-rated connector, so check every part in the path.