Focus Microwaves manufactures, since 1989, coaxial programmable (slide screw) impedance tuners from 100MHz up to 67GHz. Focus' tuners are directly controlled by the PC. Early versions using ISA cards, then PCI, then USB and today via LAN. "i" tuners carry an on-board micro-processor, memory and firmware with interpolation and tuning capability for single probe (CCMT, wideband) tuners. The wideband (iCCMT-) series is optimized for large bandwidth, high VSWR and RF power. Each tuner contains one carriage with one, two or three vertical axes, each of which carries one wideband probe (also called "slug"). Each such slug covers different parts of the bandwidth and can be inserted simultaneously or separately into the slabline (a parallel plate airline), to create controllable reflection.
*The model number of each tuner is based on the frequency range and optional on the internal structure:
« xx » = Maximum frequency [GHz]
« yy » = Minimum frequency [0.1GHz]
« zz » = Number of probes or other