A multi-section probe and a tapered probe for impedance tuners to broaden the band width of the probes and hence the band width of the tuners. Each section of the multi-section probe has a nominal length equal to one quarter wavelength at a midpoint of the operating band. The tapered probe has a length equivalent to a plurality of one quarter wavelengths of the frequency midpoint. The multi-section probe and the tapered probe are configured to transform the characteristic impedance of the tuner transmission line step-by-step or continuously to a target impedance value.