RFMW Expert Product Pick: Knowles Milli-Cap Capacitors

What made you feature the Knowles Milli-Cap® capacitor series?

I chose the Knowles Milli-Cap® series of broadband blocking capacitors to feature because they directly address one of the toughest challenges in RF and microwave design: maintaining signal integrity across broad frequency ranges while minimizing parasitics. Whether you’re designing next-generation test equipment, fiber optic modules, or broadband microwave and millimeter-wave systems, stability and performance at high frequencies are critical. Engineers need capacitors that won’t introduce distortion, won’t shift resonance under temperature extremes, and can reliably support wideband designs without eating up board space. That’s where the Milli-Cap series stands out.

The Milli-Cap capacitors are engineered for ultra-low loss operation, very low series inductance, and ultra-high series resonance. Their construction allows them to behave like an ideal capacitor across a wide frequency spectrum, while their small 0201, 0402, and 0602 footprints save board space without sacrificing performance. For broadband designs where every dB of loss and every fraction of a millimeter counts, the Milli-Cap delivers both efficiency and reliability.

What are the key features/specifications of the Milli-Cap® capacitors?

• Low loss, high Q performance
• Ultra-high series resonance
• Very low series inductance
• Single-piece construction
• Available in 0201, 0402, and 0602 footprints
• Matches typical 50Ω line widths
• Behaves like an ideal capacitor across a broad frequency spectrum

What are common markets/applications of the Milli-Cap® capacitors?

• Test equipment
• Fiber optics, including photonics, SONET, TOSA/ROSA modules
• High-speed data systems
• Broadband microwave and millimeter-wave systems