A multi-band, electro-mechanical programmable impedance tuner for the frequency range between 10 and 200 MHz uses cascades of three or more continuously variable mechanical capacitors interconnected with sets of low loss flexible or semi-rigid cables; for each frequency band a different set of cables and capacitors are used. The cables and/or variable capacitors inside each tuning block are switchable manually or remotely. Multi-section variable capacitors are also used. Instantaneous impedance tuning is effectuated by changing the state of the capacitors using electrical stepper motors. The tuner is calibrated using a vector network analyzer and the data are saved in the memory of the control computer, which then allows tuning to any user defined impedance within the tuning range. Reflection factor values between 0 and higher than 0.9 can be obtained using this tuner at all frequency bands.

A multi-band, electro-mechanical programmable impedance tuner for the frequency range between 10 and 200 MHz uses cascades of three or more continuously variable mechanical capacitors interconnected with sets of low loss flexible or semi-rigid cables; for each frequency band a different set of cables and capacitors are used. The cables and/or variable capacitors inside each tuning block are switchable manually or remotely. Multi-section variable capacitors are also used. Instantaneous impedance tuning is effectuated by changing the state of the capacitors using electrical stepper motors. The tuner is calibrated using a vector network analyzer and the data are saved in the memory of the control computer, which then allows tuning to any user defined impedance within the tuning range. Reflection factor values between 0 and higher than 0.9 can be obtained using this tuner at all frequency bands.

A multi-band, electro-mechanical programmable impedance tuner for the frequency range between 10 and 200 MHz uses cascades of three or more continuously variable mechanical capacitors interconnected with sets of low loss flexible or semi-rigid cables; for each frequency band a different set of cables and capacitors are used. The cables and/or variable capacitors inside each tuning block are switchable manually or remotely. Multi-section variable capacitors are also used. Instantaneous impedance tuning is effectuated by changing the state of the capacitors using electrical stepper motors. The tuner is calibrated using a vector network analyzer and the data are saved in the memory of the control computer, which then allows tuning to any user defined impedance within the tuning range. Reflection factor values between 0 and higher than 0.9 can be obtained using this tuner at all frequency bands.

Improved interdigital parallel plate rotary capacitors to be used in automatic MHz range tuners have a grounding technique based on bronze sliding contact to effectively and continuously lead to the ground terminal the rotating comb-like blades of the capacitor and (optional) damping resistors inserted between the sliding contact and the ground terminal. The resistors reduce the high Q of the series resonance of the capacitor with the fringe lead inductance. Tuning sensitivity is reduced and tuning accuracy and repeatability are increased.

A chip resistor includes a substrate, and a plurality of resistor elements each having a resistive film provided on the substrate and an interconnection film provided on the resistive film in contact with the resistive film. An electrode is provided on the substrate. Fuses disconnectably connect the resistor elements to the electrode. The resistive film is made of at least one material selected from the group of NiCr, NiCrAl, NiCrSi, NiCrSiAl, TaN, TaSiO.sub.2, TiN, TiNO and TiSiON.

A chip resistor includes a substrate, and a plurality of resistor elements each having a resistive film provided on the substrate and an interconnection film provided on the resistive film in contact with the resistive film. An electrode is provided on the substrate. Fuses disconnectably connect the resistor elements to the electrode. The resistive film is made of at least one material selected from the group of NiCr, NiCrAl, NiCrSi, NiCrSiAl, TaN, TaSiO.sub.2, TiN, TiNO and TiSiON.