presidio components ceramic capacitors since 1980
InterdigitatedCap
 
Home Contact Us Products Catalogs Sales Reps
Presidio Components San Diego Plant
 

Home > Products > Microvave-FO-RF-Capacitor Links

Presidio's Wire Bondable
Buried Single Layer Capacitors

Presidio's Advantage
Click for Enhanced View/Printable PDF

  • Presidio’s patented thick film technology buries electrodes into the ceramic body (Fig. 1) allowing a 10:1 advantage over a conventional construction (Fig. 2). It offers the designer: (a) more bandwidth through increased device capacitance, (b) more stable capacitance over temperature and (c) more capacitance in smaller case sizes for increased board density.

  • Filled vias connect the buried electrodes with the outside top and bottom metallization pads; 99.95% pure Au is standard for all metal connections allowing proven wire bond techniques with AuSn or conductive epoxy die attach techniques.

  • Excellent low loss performance for high Q applications as demonstrated with a 10 pF
    NPO capacitor shown in Fig. 6 below.

  • Ease of dielectric material selection: Presidio offers 3 ceramic materials while
    most other suppliers offer more than 15.

  • RoHS compliant

Presidio Advantage

Kent Simulator

Using the KENT SIMULATOR (Fig. 3), a designer can obtain commonly needed RF capacitor parameters in graphical format for popular Presidio Components RF capacitors. In addition, S-parameters for selected capacitors can be saved in S2P format. All device parameters are derived from a series transmission line model developed by Dr. Gordon Kent and available at www.presidiocomponents.com. A technical discussion of the simulation used in the Kent Simulator is presented by Gordon Kent in the “Summary of the Capacitor Simulator.”

Download the Kent Simulator

Kent simulator
Fig. 3. Kent Simulator Version 2.0
LSA1010B101MGH5C–

Typical Applications

FILTER CAPACITOR

A filter design requires a specific capacitance value, CF, and at the upper end of the filter response, fF, the effective capacity must not exceed CF by more than a specified amount of ΔC. Once CF is determined, case size, voltage rating and temperature characteristics can be selected. Typically, lower loss Class I materials like NPQ and NPO are first choice. See Fig. 4.

Kent Simulator Filter Capacitor
Fig. 4. Modeled ESR/50 and Ceff of part
NSA2525N6R8K2H5C–

RESONANCE-FREE BROADBAND COUPLING/DECOUPLING CPACITOR

Class II “BX” dielectric is typical for DC block or RF bypass applications to operate resonance free over a specified broad frequency range. Low impedance is typically more important than the capacitance value which should be large enough to cover the 3 dB low edge of the bandwidth. See Fig. 5.

Kent simulator broadband coupling/decoupling capacitor
Fig. 5. Modeled S21 and Z/50 of part
LSA1010B101MGH5C–, Class II Dielectric

MINIMUM LOSS, FINITE BAND COUPLING CAPACITOR

When minimum loss is required, e.g. a low noise circuit, a high Q capacitor with Class I dielectric (NPQ or NPO) is recommended. Any parallel resonance frequency of the capacitor should be outside of the use frequency band. The best capacitor choice puts the series resonance at the band center (approximately f0 / 2). See Fig. 6.

Kent simulator minimum loss
Fig. 6. Modeled S21 and Ceff of part
NSA3030N100J2H5C–, Class 1 Dielectric

  Top

 

© Presidio Components, Inc.
Home Products Sales Requests Contacts
Terms & Conditions
Presidio Components, Inc., has been an industry leader in the manufacture of ceramic capacitors since 1980. We provide high quality commercial capacitors, military capacitors, space capacitors, high temperature capacitors, pulse energy capacitors for EFI detonators, microwave capacitors and RF capacitors, as well as custom capacitors. Our custom products include nonstandard part sizes and voltages, including high voltage, high temperature, high "Q", custom leads, cryogenic ceramics, negative and positive temperature characteristic ceramics and piezoelectric formulations. We have a series of patented microwave and radio frequency products including patented single layer and broadband DC blocking caps. Call Presidio at (858) 578-9390.