Amphenol's APC is the first instrument-grade coaxial connector series to achieve repeatable TE11 mode resonance-free signal transmission from DC - 50 GHz with a minimum return loss of 26 dB. These 50 Ω connectors are designed primarily for use in test and measurement equipment where reliable performance is critical for repeated connect/disconnect cycles.

APC-2.4 was Amphenol's initial precision offering, and includes the male and female connectors for termination to 2.4mm rigid coaxial airline cable. Also featured are 22 between-series adapters for high-performance transistors from the 2.4mm interface to the APC-3.5, APC-7, APC-N, SMA, and Wilton K - connectorTM interfaces.

APC-3.5 connectors are a high-performance 50 Ω coaxial connector designed to exhibit low VSWR, low loss, and to be resonance-free to 34 GHz. This line features an air dielectric mating face and a thicker outer conductor shoulder. APC-3.5 designs maintain mechanical and electrical integrity through repeated mating cycles, and they mate with SMA connectors.

APC-7 connectors are primarily used with rigid 7mm airline cable. They feature a sexless coupling mechanism that permits any two APC-7 connectors to mate. Certified test reports of VSWR are provided whenever a mated pair of APC-7 connectors is ordered.

APC-N connectors can be used interchangeably with the APC-7 on rigid airline cables or equipment, and they mate with all other Type N connectors. VSWR for a mated pair of APC-N connectors is 1.06 - 12. 4 GHz and 1.08 - 18 GHz.