High Power RF Capacitors There’s a Need --- Now there’s a solution --- it’s about time! Metal Clad and Mica Chips When ceramics can’t handle the job

High Power RF Capacitors SMT Metal Clad Metal Clad Through-Hole MC / MCN Mica Chips

It’s OK to Use Large Size Chips Most companies restrict MLCC usage to 1206 or 1210 Large case MLCs (multi-layer chip sandwiches) film & mica are used--but not ceramic--at least not without special handling Film chips up to size 6040 for modems and mica up to size 2220 for CATV have been commonly used for 10 years

Typical RF Filter Board broadband amplifier Typical RF Filter Board broadband amplifier 100 Watt mobile radio power board

RF Capacitors for High Power Applications High Power…. Yes 10-200 Watts Low Power…. NO

Metal Clad for Scorching Hot Applications Lasers Airborne & Mobile Radio Manpack Radio MRI RF Coils

Benefits of Metal Clad Capacitors Run Cool: Silver plated brass cases and terminations Like miniature heat sinks Keep their cool by spreading heat Carry High Current: Ultra-high Q mica & TeflonÒ film dielectric Generate very little internal heat

Benefits of Metal Clad Capacitors Better than Ceramic: TeflonÒ & mica rated 200ºC & No derating! Overcome reluctance to use larger than 1210 Free from cracking or delamination Don’t desolder like chips Handle more current than capacitors up to twice their size

Metal Clad – Series Selection Type MCM Original Metal Clad Mica series Low values TeflonÒ >8 pF uses mica 300, 500 and 1000 VDC Wide temperature range –55 ºC to +200 ºC Non-magnetic Capacitance tolerance to ±0.25 pF ≈ 4640 & 5040 sizes

Metal Clad – Series Selection Type MIN MINiature metal clad series All the features of original series MCM 300 VDC maximum ≈ 2220 EIA case size

Metal Clad & Mica Chips Similarities Stable capacitance vs voltage, time, frequency Exact values including non-standard ratings Tight tolerance: chip ±0.1 pF, clad ±0.25 pF Voltages 100 to 1000 Vdc Relief from thermal cracking or delamination Mica chips usually less expensive than metal clad

High RF Power Capacitor Features Why use metal clad & mica chip power caps? Handle the power / heat with a single capacitor. Eliminate the need for farms of 1206 NPOs in parallel Stable capacitance versus frequency, voltage, time Nonmagnetic to minimize RF losses from eddy currents Exact-value with non-standard ratings available Tight tolerance chips to ±0.1 pF, metal clad to ±0.25pF

Mica Chips vs. Metal Clad - Differences Metal clad spreads heat Metal clad handles higher ripple currents Metal clad rated to 200° C, chips to 125°C Mica chips less expensive than metal clad All metal clad series are nonmagnetic Only type MCN mica chips are nonmagnetic

Competition for RF Power Capacitors Porcelain and NPO MLCCs historically used for RF applications 1812, 1825 and 2225 EIA size MLCs are most common NPO ceramic less costly than porcelain but --- cracking and delamination? Competition Areas of Weakness ATC Not in Digi-Key, Mouser catalogs for new designs Very limited distribution Chips may desolder with high power RF Can’t handle same power as metal clad Most series are magnetic. Johanson

Market Info – High Power RF Power Caps North American TAM RF Caps: $25+ million (est.) CDE share ≈ 10% and rapidly growing Porcelain and NPO best known RF power applications CDE’s major competitors are weak in distribution Major CDE customers: Motorola, Harris, E.F. Johnson Better ASP & less competition than commodity products

News Release – ECN November 2005 CDE Cornell Dubilier has introduced high-power RF capacitors for military/aerospace and commercial radios and transmitters, CATV, automotive and medical RF generators and other applications requiring high-frequency operation into the low gigahertz and high-temperature operation up to 200°C. These capacitors are metal clad in silver plated metal cases to enable ultra-low inductance terminations and heat spreading for high power operation. The mica and Teflon® dielectric systems assure low ESR to greater than 1 GHz and high ripple current capabilities and stability in subminiature sizes. All styles are non-magnetic and are suitable for use in critical NMR MRI applications. Volume pricing for a 10 pF, ±0.5 pF unit is $0.39.

Applications for Metal Clad & Mica Chips Communications RF and microwave power amplifiers and transmitters Mobile radio – typically 10 to 200 watts Handheld, manpack, vehicular and base station radios Airborne, ground, naval military & commercial radios Telemetry Wherever 1812, 1825, 2225 porcelain or NPO are used

Applications for Metal Clad & Mica Chips Medical RF coils for MRI Electrosurgery & curettage RF ablation (heart surgery) CO2 lasers for cosmetic and optical YAG lasers for skin and soft tissue

Applications for Metal Clad & Mica Chips Industrial CO2 & YAG lasers for industrial cutting RF plasma generators for semiconductor fab WLAN and WLL transmitters for WiMAX Downhole logging – high temperature Underhood automotive - high temperature CATV repeaters exposed to lightning pulses

RF Capacitor Properties DIELECTRIC ADVANTAGES DISADVANTAGES Teflon MIN MCM Metal clad resist desoldering Lowest dielectric absorption (DA) Very stable Temperature rating to 200ºC Low HF losses (low ESR & ESL) More expensive than mica Very limited values ≤33 pF Wider Temperature coefficient Mica Extremely stable Exact pF values, tight tolerances Voltages to 1 kV Temperature ratings to 200 ºC Very high Q DA not as low as Teflon® Chips may desolder continued

RF Capacitor Properties DIELECTRIC ADVANTAGES DISADVANTAGES NPO Ceramic Very stable High Q Low inductance Small sizes Chips may desolder Thermal shock, delamination Exact values hard to get Low power Porcelain Relatively expensive Thermal shock / delamination

Part Numbering System

Definitions RF (Radio) Frequencies: VHF (very high frequency) 30 MHz to 300 MHz UHF (ultra high frequency) 300 MHz to 3 GHz Q: Quality factor - capacitor merit. Inverse to DF Very critical for RF applications to minimize distortion Provides stability and long life DF (dissipation factor): measure of the total AC resistances in a capacitor that causes power loss and capacitor heating

Definitions ESR (equivalent series resistance): Resistance in capacitor plates and leads Causes power loss as heat in high ripple, RF ESL (equivalent series inductance): Inductance in terminations, leads and capacitor plates ESL can be a serious problem at high RF frequencies Stacked vs. wound capacitors: Insulation stacked in a multi-layer (MLC) sandwich Most film and aluminum caps are rolled in a tube MLC mica, film and ceramic preferred in RF apps

Definitions Stability: Change in cap with change in time, frequency, voltage Temperature Coefficient (TC): Change in cap with temperature --- measured in ppm/°C e.g., a 50 pF cap changes 0.5 pF (1%) from 25°C to 125°C Formula for TC = ∆C x 106 ÷ C x ∆T = ppm/°C TC = (125°C – 25°C) x 106 ÷ 50 pF x 100° = 100 ppm Thus, a 100 ppm change, which is smaller than 1%

Contacts Commercial issues, price and delivery: Bea Gravelle bgravelle@cde.com Technical information: Bob Sevigny rsevigny@cde.com

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