Self Resonating frequency of Inductor

[MobiNaz]

Hello all,

I am searching for an inductor with Self Resonating frequency of 5.25 and 10.5 GHz. But am not able to get an inductor at 5.25 Ghz however inductors are available at 5.3 and 5.2 GHz. Which one is better and why?

Could anyone please refer anyone where I can get the chip inductors at low price.
Thanks in advance.

 

[tony_lth]

There are several posts in this forum which have discussed about SRF of inductor. maybe you can find SMT inductor at 5.3G, I am afraid that you can't find one at 10.5G. For 10.5G bias RF choke, usually use microstrip bias with radia stub or open stub. You can find many inductors at Coilcraft or Maruwa, and they also provide SPICE model of the RF inductor, then you can simulate, see what happens at 5.3G and 10.5G.

 

[vfone]

The frequency difference between 5.2GHz, 5.25GHz and 5.3GHz is 1%, so will be no difference which inductor SRF you chose.
Anyway at this frequencies, small parasitics on the PCB layout will affect inductor SRF more than 1%.

 

[mfarhan1]

inductors are normally used below SRF and at the point of max Q. I believe you can use any of them if your operational frequency of the circuit is below 5GHz

 

[pewang]

if you review that SRF definition, it's obviously above the SRF frequency the inductor will play as a capacitor more and more, so if you want a inductor then keep it work far below the SRF frquency.

 

[flyhigh]

Hi

Don't rely on SRF of inductor to create an RF choke, it doesn't work all the time. Better solution is to apply a series connection of an inductance that will be high impedance at 5 GHz and one that will be high impedance at 10 GHz.

flyhigh

 

[spid3rx]

coilcraft 0402HP series had the inductors with SRF up to 16GHz. you may want to have a look on those.
just to note the SRF might slightly shifted if mounted due to loading.

 

[manishmehta]

at resonance freq the Q is zero,therefore you can not work on resonance so you have to choose that freq where Q is max, secondally you have to keep in mind that insertion loss must be in acceptable value
thanks


I am searching for an inductor with Self Resonating frequency of 5.25 and 10.5 GHz. But am not able to get an inductor at 5.25 Ghz however inductors are available at 5.3 and 5.2 GHz. Which one is better and why?

Could anyone please refer anyone where I can get the chip inductors at low price.
Thanks in advance.[/QUOTE]