Courtesy of Knowles Precision Devices : Non-magnetic variable inductors from Johanson MFG, combine small size with high performance
These Johanson Manufacturing branded Variable Inductors, 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 only 9mm/0.35″ in SMD, vertical SMD and thru-hole versions, they are ideal for applications consistent with MRI/NMR Systems, Radios/Jammers, Power Amplifiers, Radar, Avionics Instrumentation and Test Equipment. Applications where higher power handling & 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 118nH, 2 to 7 turns with Q as high at 121 : 100MHz, SRF 0.7 – 1.2GHz with customized versions available for non-cataloged values. All parts are RoHs compliant. Johanson Manufacturing is a world-class supplier of trimmer capacitors, non-magnetic variable inductors and microwave tuning elements.
Note: Dielectric Laboratories (DLI), Novacap, Syfer Technology and Voltronics came together to form a single organisation, Knowles Precision Devices – they have now been joined by Johanson Manufacturing and Compex. This entity has a combined history exceeding 200 years and is a division of Knowles Corporation of USA, an independent publicly traded company.