Johanson Manufacturing branded Variable Inductors, which are available from Knowles Precision Devices combine small size and high performance with non-magnetic properties. Inductors and variable inductors are necessary elements of many RF products. They are used for matching and loading low noise amplifiers, power amplifiers and mixers, as well as for providing frequency- selective resonant circuits in variable-frequency oscillators.
With an overall height of 9 mm/0.35" in SMD, vertical SMD and thru-hole versions, they are suitable for applications consistent with MRI/NMR systems, radios/jammers, power amplifiers, radar, avionics instrumentation and test equipment, as well as applications where higher power handling and high Q values are essential.
The coils and PTFE cores have a patented precision machined design to guarantee a constant winding pitch and consistent relationship to the printed circuit board. Tuning is done by means of threaded PTFE and Non-Magnetic Copper Alloy core. They have superb shock, vibration and thermal tolerances and operate over the temperature band -40ºC to +85ºC.
Catalog parts have nominal values of 33 to 118 nH, 2 to 7 turns with Q as high at 121: 100 MHz, SRF 0.7 – 1.2 GHz with customized versions available for non-cataloged values. All parts are RoHs compliant.