OverviewAll product unitsProduct unitPassive ComponentsProduct groupSignal & CommunicationsProduct familyRF InductorsProduct seriesWE-CAIR Air Coil

WE-CAIR Air Coil

Size Dimen­sionsL
(mm)
W
(mm)
H
(mm)
Mount
1322 2.21 1.42 1.37 SMT
1340 4.04 1.42 1.37 SMT
3136 3.68 3.05 3.18 SMT
3168 6.68 3.05 3.18 SMT
4248 4.83 3.81 4.2 SMT
5910 10.55 6.35 5.9 SMT

Characteristics

  • Inductance values from 1.65 nH up to 538 nH
  • Very high quality factor >100
  • High self-resonant frequency
  • High currents up to 4.0 A
  • Inductance tolerances 2%, 5 % and 10 %
  • Pick and place process possible
  • Good solderability (tinned connector pins)
  • Operating temperature: -40 °C to +125 °C

Applications

  • Especially for RF applications
  • Ideal for high current applications
  • Broad band filter
  • RF-Decoupling

Modelithics Simulation Models

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Products

All
1322
1340
3136
3168
4248
5910
Order Code Data­sheet Simu­lation DownloadsL
(nH)
Tol. LTest Condition LQmin.Test Condition QRDC max.
(mΩ)
IR
(A)
fres
(GHz)
Design Kit Samples
744910016SPEC
9 files 1.65 ±10% 800 MHz 100 800 MHz 4 1.6 1074491
744913025SPEC
8 files 2.5 ±5% 150 MHz 140 150 MHz 1.1 4 12.574491
744910025SPEC
9 files 2.55 ±5% 800 MHz 100 800 MHz 5 1.6 8.274491
744910038SPEC
9 files 3.85 ±5% 800 MHz 100 800 MHz 6 1.6 7.574491
744913050SPEC
8 files 5 ±5% 150 MHz 140 150 MHz 1.8 4 6.574491
744913050GSPEC
8 files 5 ±2% 150 MHz 140 150 MHz 1.8 4 6.5
744910054SPEC
9 files 5.45 ±5% 800 MHz 100 800 MHz 8 1.6 774491
744911056SPEC
9 files 5.6 ±5% 800 MHz 100 800 MHz 9 1.6 6.574491
744911071SPEC
9 files 7.15 ±5% 800 MHz 100 800 MHz 10 1.6 674491
744913080SPEC
8 files 8 ±5% 150 MHz 140 150 MHz 2.6 4 574491
744913080GSPEC
8 files 8 ±2% 150 MHz 140 150 MHz 2.6 4 5
744911088SPEC
9 files 8.8 ±5% 800 MHz 100 800 MHz 12 1.6 674491
744911098SPEC
9 files 9.85 ±5% 800 MHz 100 800 MHz 13 1.6 5.2
744913112SPEC
8 files 12.5 ±5% 150 MHz 137 150 MHz 3.4 4 3.374491
744913112GSPEC
8 files 12.5 ±2% 150 MHz 137 150 MHz 3.4 4 3.3
744911112SPEC
9 files 12.55 ±5% 800 MHz 100 800 MHz 14 1.6 4.674491
744914117SPEC
9 files 17.5 ±5% 150 MHz 100 150 MHz 4.5 4 2.274491
744914117GSPEC
9 files 17.5 ±2% 150 MHz 100 150 MHz 4.5 4 2.2
744913118SPEC
8 files 18.5 ±5% 150 MHz 132 150 MHz 3.9 4 2.574491
744913118GSPEC
8 files 18.5 ±2% 150 MHz 132 150 MHz 3.9 4 2.5
744912122SPEC
9 files 22 ±5% 150 MHz 100 150 MHz 4.2 3 3.274491
744914122SPEC
9 files 22 ±5% 150 MHz 102 150 MHz 5.2 4 2.174491
744912122GSPEC
9 files 22 ±2% 150 MHz 100 150 MHz 4.2 3 3.2
744914122GSPEC
9 files 22 ±2% 150 MHz 102 150 MHz 5.2 4 2.1
744912127SPEC
9 files 27 ±5% 150 MHz 100 150 MHz 4 3.5 2.774491
744912127GSPEC
9 files 27 ±2% 150 MHz 100 150 MHz 4 3.5 2.7
744914128SPEC
9 files 28 ±5% 150 MHz 105 150 MHz 6 4 1.874491
744914128GSPEC
9 files 28 ±2% 150 MHz 105 150 MHz 6 4 1.8
744912133SPEC
9 files 33 ±5% 150 MHz 100 150 MHz 4.8 3 2.574491
744912133GSPEC
9 files 33 ±2% 150 MHz 100 150 MHz 4.8 3 2.5
744914135SPEC
9 files 35.5 ±5% 150 MHz 112 150 MHz 6.8 4 1.574491
744914135GSPEC
9 files 35.5 ±2% 150 MHz 112 150 MHz 6.8 4 1.5
744912139SPEC
9 files 39 ±5% 150 MHz 100 150 MHz 4.4 3 2.174491
744912139GSPEC
9 files 39 ±2% 150 MHz 100 150 MHz 4.4 3 2.1
744914143SPEC
9 files 43 ±5% 150 MHz 106 150 MHz 7.9 4 1.274491
744914143GSPEC
9 files 43 ±2% 150 MHz 106 150 MHz 7.9 4 1.2
744912147SPEC
9 files 47 ±5% 150 MHz 100 150 MHz 5.6 3 2.174491
744912147GSPEC
9 files 47 ±2% 150 MHz 100 150 MHz 5.6 3 2.1
744912156SPEC
9 files 56 ±5% 150 MHz 100 150 MHz 6.2 3 1.574491
744912156GSPEC
9 files 56 ±2% 150 MHz 100 150 MHz 6.2 3 1.5
744912168SPEC
9 files 68 ±5% 150 MHz 100 150 MHz 8.2 2.5 1.574491
744912168GSPEC
9 files 68 ±2% 150 MHz 100 150 MHz 8.2 2.5 1.5
744912182SPEC
9 files 82 ±5% 150 MHz 100 150 MHz 9.4 2.5 1.374491
744912182GSPEC
9 files 82 ±2% 150 MHz 100 150 MHz 9.4 2.5 1.3
744918190SPEC
9 files 90 ±5% 50 MHz 100 50 MHz 15 3.5 1.14
744912210SPEC
9 files 100 ±5% 150 MHz 100 150 MHz 12.3 1.7 1.274491
744912210GSPEC
9 files 100 ±2% 150 MHz 100 150 MHz 12.3 1.7 1.2
744918211SPEC
9 files 111 ±5% 50 MHz 100 50 MHz 15 3.5 1.02
744912212SPEC
9 files 120 ±5% 150 MHz 100 150 MHz 17.3 1.5 1.174491
744912212GSPEC
9 files 120 ±2% 150 MHz 100 150 MHz 17.3 1.5 1.1
744918213SPEC
9 files 130 ±5% 50 MHz 100 50 MHz 20 3 0.9
744918217SPEC
9 files 169 ±5% 50 MHz 100 50 MHz 25 3 0.875
744918220SPEC
9 files 206 ±5% 50 MHz 100 50 MHz 30 3 0.8
744918222SPEC
9 files 222 ±5% 50 MHz 100 50 MHz 35 3 0.73
744918224SPEC
9 files 246 ±5% 50 MHz 100 50 MHz 35 3 0.685
744918230SPEC
9 files 307 ±5% 50 MHz 100 50 MHz 35 3 0.66
744918238SPEC
9 files 380 ±5% 50 MHz 100 50 MHz 50 2.5 0.59
744918242SPEC
9 files 422 ±5% 50 MHz 100 50 MHz 60 2.5 0.54
744918249SPEC
9 files 491 ±5% 50 MHz 100 50 MHz 65 2 0.535
744918254SPEC
9 files 538 ±5% 50 MHz 100 50 MHz 90 2 0.49
Order Code Data­sheet Simu­lation
744910016SPEC
744913025SPEC
744910025SPEC
744910038SPEC
744913050SPEC
744913050GSPEC
744910054SPEC
744911056SPEC
744911071SPEC
744913080SPEC
744913080GSPEC
744911088SPEC
744911098SPEC
744913112SPEC
744913112GSPEC
744911112SPEC
744914117SPEC
744914117GSPEC
744913118SPEC
744913118GSPEC
744912122SPEC
744914122SPEC
744912122GSPEC
744914122GSPEC
744912127SPEC
744912127GSPEC
744914128SPEC
744914128GSPEC
744912133SPEC
744912133GSPEC
744914135SPEC
744914135GSPEC
744912139SPEC
744912139GSPEC
744914143SPEC
744914143GSPEC
744912147SPEC
744912147GSPEC
744912156SPEC
744912156GSPEC
744912168SPEC
744912168GSPEC
744912182SPEC
744912182GSPEC
744918190SPEC
744912210SPEC
744912210GSPEC
744918211SPEC
744912212SPEC
744912212GSPEC
744918213SPEC
744918217SPEC
744918220SPEC
744918222SPEC
744918224SPEC
744918230SPEC
744918238SPEC
744918242SPEC
744918249SPEC
744918254SPEC
Samples
Order Code Data­sheet Simu­lation DownloadsL
(nH)
Tol. LTest Condition LQmin.Test Condition QRDC max.
(mΩ)
IR
(A)
fres
(GHz)
Design Kit Samples

What is the Quality Factor Q?

The quality factor Q is an essential characteristic parameter and one of the first creterias that every RF engineer should take into account. The Q factor is given either as minimum or as typical value at a defined frequency point. In the case of Würth Elektronik, the Q factor is given as the minimum value in order to guarantee customers a reliable minimum level.

Basically, the Q factor is the ratio between the inductive reactance XL and the losses RS and is an indicator of how ideal an inductor is. For inductors with air or ceramic cores, the resistance RS is mainly due to the resistivity of the conductor in the inductor device. A higher Q factor means less losses in the component.

Self Resonant Frequency

Because the winding structure of any coil of wire will exhibit some capacitance, the inductor will serve as a parallel resonant tank circuit with an associated self-resonance frequency (SRF). As with conventional inductors, SRF indicates up to which frequency the inductor behaves as an inductor.

Exactly at the SRF the inductor with its parasitic capacitance behaves as a resonance circuit with an almost infinite high impedance, only circuit losses limit the high value of the impedance. Beyond the SRF the “inductor” behaves like a capacitor

Increasing the inductance and/or the parasitic capacitance lowers the SRF, and vice versa. This is the reason why the higher the inductance value, the lower the SRF.

In case of choke applications in which inductors are used, the best signal blocking occurs shortly below the SRF, where the impedance is very high and thus the attenuation reaches its maximum. For filter or impedance-matching applications, it is more important to have constant inductance in the relevant frequency range, which means the SRF of the inductor should be well above the operating frequency of the circuit.

Rated Current in high frequency application

The rated current is specified as the maximum DC current (A or mA) that causes a defined temperature rise (i.e. ΔT = 40 K). The temperature rise plus the ambient temperature must not exceed the maximum operating temperature. For high current applications, please select the specific air core inductors: WE-KI HC, WE-ACHC and WE-CAIR.

RF inductors and Antenna Matching

How Antenna Matching works

With the help of the Smith chart, the complex antenna feed point impedance, consisting of resistive and reactive values, can be represented graphically. In a matched antenna, the impedance at the operating frequency is close to the middle of the Smith chart and therefore close to the impedance of 50 Ω. This can be achieved by using RF inductors and RF capacitors. A pi matching network is particularly useful for this purpose, since it can be used flexibly for antenna matching from almost any other impedance. In practice, antenna matching works through iterative steps.

In addition to the WE-MCA Antennas, we offer our customers a development-accompanying antenna service. We support from the antenna selection over the antenna placement up to the antenna matching.

Website: www.we-online.com/antenna-matching

E-Mail: antenna.matching@we-online.com

We are also offering an Antenna Matching Design Kit that contains all the components needed for your antenna matching. This Design Kit with order code 748001, contains chip antennas WE-MCA, multilayer ceramic inductors WE-MK size 0402, high frequency chip capacitors WCAP-CSRF in size 0402 and RF coaxial cables WR-CXARY working up to 18 GHz

Assortments

Articles from this product series can be found in the following assortments: