N
Member
Prototypes use SMA, but production wants SMP for blind-mate. Any gotchas switching from SMA to SMP? Power handling differences?
RF connector selection: SMA vs SMP for production?
L
Admin
Good question — a few gotchas we see when moving from SMA to SMP:
- Detent type: SMP comes in full detent, limited detent and smooth bore. Full detent holds firmly but has lower rated mating cycles (often around 100); smooth bore can be rated for about 1,000 cycles but needs mechanical retention. For blind-mate board-to-board, the usual pattern is limited or full detent on one board and smooth bore on the other, with a bullet adapter between them.
- Misalignment: a bullet adapter accommodates radial misalignment of about ±0.25 mm and some axial float; check the vendor's values against your mechanical tolerance stack-up between the two boards.
- Frequency and RF performance: SMP is typically rated to about 40 GHz, more than enough if your SMA prototypes work; but the bullet adds a discontinuity, so re-measure return loss with the actual bullet length.
- Power: SMP is smaller, so average power handling is lower than SMA, typically a few tens of watts at low GHz and dropping with frequency. Check the derating curve for your frequency and temperature.
- Test access: you lose the easy SMA bench connection, so plan for SMP-to-SMA test cables and include them in calibration.
Question: what frequency and power level are you running, and is it board-to-board or board-to-chassis?
— rfforum 编辑部 / Editorial Team
- Detent type: SMP comes in full detent, limited detent and smooth bore. Full detent holds firmly but has lower rated mating cycles (often around 100); smooth bore can be rated for about 1,000 cycles but needs mechanical retention. For blind-mate board-to-board, the usual pattern is limited or full detent on one board and smooth bore on the other, with a bullet adapter between them.
- Misalignment: a bullet adapter accommodates radial misalignment of about ±0.25 mm and some axial float; check the vendor's values against your mechanical tolerance stack-up between the two boards.
- Frequency and RF performance: SMP is typically rated to about 40 GHz, more than enough if your SMA prototypes work; but the bullet adds a discontinuity, so re-measure return loss with the actual bullet length.
- Power: SMP is smaller, so average power handling is lower than SMA, typically a few tens of watts at low GHz and dropping with frequency. Check the derating curve for your frequency and temperature.
- Test access: you lose the easy SMA bench connection, so plan for SMP-to-SMA test cables and include them in calibration.
Question: what frequency and power level are you running, and is it board-to-board or board-to-chassis?
— rfforum 编辑部 / Editorial Team