Brochure

ManualsBrandsKEMET ManualsCapacitorsHiQ-CBR Ceramic Capacitor, MLCC, RF 100pF, 25VDC, 0402, ±1 %

P.O. Box 5928, Greenville, South Carolina 29606 U.S.A.

Tel: 864.963.6300 Fax: 864.963.6521

FREQUENTLY ASKED QUESTIONS

RF & MICROWAVE PRODUCTS

WHAT IS RF?

RF stands for Radio Frequency, which has a frequency range of 30KHz - 300GHz. RF

capacitors help tune antenna to the correct frequency. The technical term is resonator

circuit, which consists of an Inductor + an RF Capacitor

WHY IS ESR SO CRITICAL IN HIGH FREQUENCY APPLICATIONS?

ESR is a summation of losses in a capacitor. In MLCCs, these losses are mostly Rsd /

Dielectric Loss and Rsm / Metal loss (electrode, termination, and electrode-to-

termination connection). ESR is a critical electrical parameter in KEMET’s Tantalum

Mn0

and Tantalum Polymer product lines. For standard MLCCs in low frequency

applications (<<10 MHz), the ESR is typically so low (due to the multilayer chip

construction, and the application frequency) that ESR is not even measured in routine

testing; rather, DF (Dissipation Factor) is typically used.

Modeled ESR for standard MLCCs in lower frequency applications is available in

KEMET’s SPICE program. ESR varies with frequency.

In high frequency applications (>30 MHz), ESR is critical, as the added resistance can

lead to undesirable component heating, thermal breakdown, or worse, catastrophic

failure.

WHAT IS Q?

Q also varies with frequency, and is referred to in two different terminologies:

  









where |Xc| is the absolute value of the reactance in Ohms, or

  





where DF = Dissipation Factor

DF is calculated as



π

where f is the frequency in Hertz, and c is the capacitance in

Farads.

KEMET measures ESR and Q in our own test labs in Simpsonville, SC.

Summary of content (5 pages)

PAGE 1
FREQUENTLY ASKED QUESTIONS RF & MICROWAVE PRODUCTS WHAT IS RF? RF stands for Radio Frequency, which has a frequency range of 30KHz - 300GHz. RF capacitors help tune antenna to the correct frequency. The technical term is resonator circuit, which consists of an Inductor + an RF Capacitor WHY IS ESR SO CRITICAL IN HIGH FREQUENCY APPLICATIONS? ESR is a summation of losses in a capacitor.
PAGE 2
POWER DISSIPATION Power is calculated as follows:  𝑃 = 𝐼 2 ∗ 𝐸𝑆𝑅 where I is the current passing through the capacitor, and ESR is the Equivalent Series Resistance. Power Dissipation is a term used to describe the power dissipated within the capacitor. Since ESR is directly proportional to power, low ESR is critical to ensure the highest efficiency and stability.
PAGE 3
During testing at KEMET, higher voltage devices are submerged in an insulating fluid to ensure testing measures the actual voltage capability of the dielectric itself. S-PARAMETER S-Parameter (scattering matrix) is a tool that quantifies how RF energy propagates through a multi-port network. S-Parameters can be used to describe a very complicated network as a simple “black box”. RF engineers uses S-Parameter as a primary quantity to design RF circuits.
PAGE 4
      Tracer width Pad dimensions Board type Board thickness Solder type Solder thickness S-PARAMETER AND ESR MEASUREMENT TECHNIQUE KEMET tests S-Parameter and ESR using the equipment specified, and pictured, below: S-Parameters  Agilent E5071C Vector Network Analyzer (300kHz - 20GHz)  Gore OTD01036 Cables  RHM-06 Probe Station  Cascade Probe Positioners  GGB 350um GSG Probes  Rogers 4003 20mil Substrate ESR  Boonton 34A Coaxial Resonant Line P.O.
PAGE 5
WHAT IS SRF AND PRF? SRF (Series Resonant Frequency) is a very common electrical parameter used in RF design. PRF (Parallel Resonant Frequency) is less commonly used. Due to the high variability of PRF (based on chip orientation on the PCB), KEMET will specify a minimum value upon request. P.O. Box 5928, Greenville, South Carolina 29606 U.S.A. Tel: 864.963.6300 Fax: 864.963.