1800nH Broadband Inductors Ultra Wideband Metal Composite Inductor 10MHz - 20GHz

Product Overview

The HALT60008 is a broadband conical inductor designed for bias tee and RF decoupling applications from 10 MHz to 20 GHz. It delivers 1800 nH (1.8 µH) of nominal inductance with a ±20% tolerance at 10 MHz, achieved through a continuously tapered conical winding of 0.08 mm (80 µm) oxygen-free copper wire with polyimide insulation.

The conical winding architecture replaces the uniform-diameter turns of a conventional solenoid with a continuously tapering diameter from apex to base. This geometry distributes inter-turn parasitic capacitance along a mechanical gradient rather than concentrating it at a single electrical node. The result is an impedance profile that rolls off smoothly with frequency, free of the discrete self-resonant peak that limits solenoid chokes to narrowband operation.

At 500 mA continuous DC current (rated for ΔT ≤ 15°C), the HALT60008 supports bias current requirements for GaN power amplifier drain feeds, high-power laser driver circuits, and wideband receiver front-end bias networks. The air-core construction eliminates magnetic saturation, ensuring the full 1800 nH inductance is maintained regardless of DC bias level.

The component operates from -55°C to +125°C and is shipped with fixture-characterized .s2p Touchstone data (10 MHz–20 GHz, 201 points, TRL-de-embedded to the component lead reference plane) for direct import into RF circuit simulators including Keysight ADS, AWR Microwave Office, and Ansys HFSS.

This product variant is aimed at engineers evaluating choke technologies for new designs. It includes side-by-side performance comparisons against multilayer ceramic chip inductors and cascaded solenoid approaches, plus a structured four-step evaluation procedure for bench validation.

Complete Technical Specifications

Technology Comparison: Choosing the Right RF Choke

Engineers specifying a bias tee choke face a technology decision. The following tables compare the conical inductor approach against the alternatives commonly evaluated during component selection.

Conical Inductor vs. Multilayer Ceramic Chip Inductors

Conical Inductor vs. Cascaded Solenoidal Inductors

Multi-Frequency Operational Performance

Each unit is verified on a calibrated vector network analyzer using microstrip calibration fixtures with TRL de-embedding:

Key Performance Advantages

• Extreme Broadband Range (10 MHz – 20 GHz): Provides continuous, flat RF isolation from low MHz to microwave frequencies in a single component, replacing multiple cascaded inductors.
• Robust 0.08 mm Wire Winding: Wound with 80 µm fine copper wire, enabling 1800 nH inductance while supporting 500 mA of DC bias current.
• Eliminates Cascade Resonances: Single-component solution suppresses signal dips and phase distortions caused by multi-stage inductor biasing.
• Air-Core Saturation Protection: Prevents magnetic saturation at high current levels, ensuring inductance stability under varying temperature and bias conditions.
• Solderable Flying Leads: Standard gold/tin-plated copper flying leads on both ends for easy integration onto microwave microstrips.

Recommended Evaluation Procedure

1. Request .s2p Data: Import the Touchstone file into your circuit simulator (Keysight ADS, AWR MWO, Ansys HFSS) with your PCB stack-up for first-pass prediction.
2. Fabricate Test Coupon: Build a simple microstrip bias tee on your target substrate. Characterize S21 and S12 on a calibrated VNA.
3. Compare Simulation to Hardware: Below 18 GHz, correlation between .s2p simulation and measured data is typically within 1 dB. Above 20 GHz, EM co-simulation with the provided HFSS model is recommended.
4. Temperature Verification: For applications operating at temperature extremes, request extended-temperature S-parameter characterization data from Hoan.

Assembly Quick Reference

1. Orientation: Cone tip (small end) perpendicular (≈90°) to the RF transmission microstrip line.
2. Lead Trim: Keep the apex flying lead between solder fillet and first turn as short as possible, ideally ≤0.3 mm. At 20 GHz, even a 0.5 mm lead wire acts as a significant parasitic inductor.
3. Base Connection: Solder the wide end to the DC bias pad. Place 100 pF parallel with 10 nF ceramic bypass capacitors within 1 mm.
4. Epoxy Fixation (mandatory): Apply a micro-dot of non-conductive, low-outgassing epoxy (Epotek H70E or H65) on the winding side to prevent resonant microphonic vibrations under mechanical excitation.
5. Soldering: Controlled micro-soldering tip temperature 280–320°C for ≤3 seconds per joint. Compatible with lead-free SAC305 solder and high-melting-point eutectic AuSn or PbSn solder alloys.

Applications by Industry Sector

• Telecom Infrastructure: High-power optical transceiver bias tees (100G/400G), 5G backhaul radio bias networks
• Defense & Radar: GaN SSPA drain bias feed in X/Ku-band T/R modules, EW receiver front-end bias
• Satellite Communications: LNA/PA bias in Ku-band transponder payloads
• Test & Measurement: VNA frequency extender bias tees, on-wafer probe station bias networks

Frequently Asked Questions

Q: At what frequency should I transition from a conical inductor to a distributed-element bias network?
A: Conical inductors are effective where a single-component broadband solution is needed from low MHz to microwave frequencies. Above 40 GHz, thin-film or distributed-element bias networks may offer better performance. Below 10 MHz, the required inductance exceeds practical conical dimensions, and a separate low-frequency choke may supplement the conical inductor in the bias network.

Q: How does the HALT60008 differ from other HALT60008 variants?
A: All HALT60008-series inductors share identical core specifications (1800 nH, 0.08 mm wire, 10 MHz–20 GHz, 500 mA). The HALT60008 provides technology comparison context—side-by-side benchmarks against ceramic and cascaded alternatives—plus a step-by-step evaluation procedure for engineers selecting among competing choke technologies. Other variants (A–F) provide application-specific integration and deployment guidance.

Q: Is competitive benchmark data available under NDA?
A: Hoan provides .s2p data from characterized standard products for customer evaluation. Direct competitive comparison test data from standardized fixtures is available under mutual NDA for qualified opportunities.