The patented Low Frequency Tuners (LFT) are a fraction of the size large of equivalent CCMT slide screw tuners that would use transmission lines and capacitive probes (slugs).
LFT use three or more tuning sections connected in cascade. Each section includes a transmission line (cable) and a parallel plate (rotary) air capacitor connected to ground. Proprietary software allows optimizing the size of the capacitors, the length of the cables and the number of tuning sections in order to best cover the Smith chart over a given bandwidth.
The capacitors are controlled by the same precise stepping motors and electronics, as used in all FOCUS tuners and impedance synthesis employs the same concepts used in the calibration techniques, impedance and tuning interpolation and tuning algorithms of the multi-harmonic tuners, MPT. Whereas therefore, the idea itself is simple, the technology which allows instantaneous tuning to any impedance, with an accuracy of 40dB or better, is the result of long development on other tuner types.
Work is ongoing to launch tuners down to 1MHz.
*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