High Impedance Isolation Air Core Inductor Laser Stripped Leads Air Core Choke Notch Filter Precision

Custom Air Core Inductor High Impedance Isolation Notch Filter Agile Small Scale Volume Ramp Up Laser Stripped Leads

HALA-CUSTOM-NF: High-Impedance Isolation & Notch Filter Precision Air Core Inductor with Agile Startup Scaling

High-Impedance Isolation & Notch Filtering Precision

The HALA-CUSTOM-NF is designed for RF notch filter and high-impedance isolation applications where precise inductance determines the notch center frequency. A 1% inductance variation shifts a 2.45GHz notch by approximately 12MHz — enough to miss a WLAN blocker. The NF addresses this with ±10% standard and ±5% high-precision inductance tolerance binning, combined with 100% per-coil RF testing (L, Q, SRF, R_DC) to verify notch center frequency consistency across the full production lot.

The air core architecture provides critical advantages for notch filters: self-resonant frequency >20GHz ensures SRF is well above the notch center (SRF >3* fnotch) for clean, spurious-free stopband performance. Q factor ≥100 at 1GHz delivers deep notch depth — S21 >30dB typical at notch center with -3dB bandwidth <2% of center frequency. QL (loaded Q) >50 at 1GHz enables sharp filter selectivity without the temperature-dependent Q drift that characterizes ferrite-based filters. The high-impedance isolation exceeds 40dB at the notch center, providing effective blocker rejection for adjacent channel interference in dense spectrum environments.

Agile Small-Scale Volume Ramp-up for Startups

Traditional inductor vendors impose minimum order quantities of 1,000–10,000 pieces — prohibitive for startups validating a new RF product concept. The HALA-CUSTOM-NF offers an agile scaling path: start with 10 pieces for bench validation, scale to 500 for pilot builds, and ramp to 5,000+ for production — all on the same HALA precision automated winding platform with identical process parameters. No minimum production commitment, no NRE charges for standard geometries, and startup-friendly pricing that reduces the financial barrier to custom RF passives. The same mandrel, wire, tension settings, and test station are used at every scale, ensuring that performance measured at prototype remains valid at production volumes.

Stress-Free Laser Stripping for Delicate Leads

Fine-wire air core inductors (0.03–0.05mm) are particularly vulnerable to mechanical stripping damage. Laser stripping eliminates this risk with non-contact enamel removal, <5μm copper surface impact, and zero mechanical stress on leads. The result is consistent lead quality without micro-cracking or work-hardening — critical for notch filters where lead parasitics affect the precision of the S21 null.

Key Specifications

Applications

• WLAN/Wi-Fi Coexistence Filters — 2.4/5/6GHz notch filters for multi-radio coexistence
• LTE/5G FR1 B41 Band-Stop Filters — high Q for sharp filter skirts
• GNSS L1/L2/L5 Pre-Filtering — narrowband notch for out-of-band jammer rejection
• Startup RF Product Development — 10-piece MOQ, agile ramp-up, no NRE

Contact us with your notch frequency, isolation target, and production volume forecast. Prototype quantities with full S21 notch characterization ship in 5–7 business days.