Microwave Circulator with Water Load (HY-BH26 / HY-BH22)

Overview

The Huiyan HY-BH26 and HY-BH22 Microwave Circulators with Integrated Water Load are engineered for high-power, continuous-wave (CW) microwave systems operating at the industrial, scientific, and medical (ISM) frequency band of 2.45 GHz. These non-reciprocal three-port ferrite devices utilize external magnetic biasing to enforce unidirectional signal flow—port 1 → port 2 → port 3 → port 1—enabling critical system-level functions including source isolation, reflected power management, and load protection. Unlike passive isolators, circulators provide bidirectional functionality within a single compact assembly, making them indispensable in magnetron- or solid-state amplifier-based systems where impedance mismatches, arcing, or thermal runaway must be actively mitigated. The integrated water-cooled load absorbs reverse-traveling energy from port 3, converting it into thermal energy dissipated via deionized water circulation, thereby eliminating the need for separate dummy loads and reducing system footprint and interconnect losses.

Key Features

• Ferrite-based non-reciprocal operation with permanent magnet biasing, optimized for stable performance across ambient temperature fluctuations (0–40 °C)
• Integrated high-efficiency water load rated for 1.5 kW CW duty cycle, featuring stainless-steel cooling channels and leak-tested O-ring seals
• Low insertion loss (≤0.3 dB) ensures minimal forward-path attenuation, preserving source efficiency and measurement accuracy
• High isolation (>20 dB) between adjacent ports prevents reflected power from re-entering the RF source, protecting sensitive amplifiers and magnetrons
• Low VSWR (<1.2:1) at all ports minimizes standing wave formation and improves power transfer integrity across the entire waveguide interface
• Standard rectangular waveguide flanges compliant with MIL-DTL-3922/67 (BJ-26/WR-340) and MIL-DTL-3922/68 (BJ-22/WR-430) specifications
• Robust aluminum alloy housing with anodized finish for EMI shielding, mechanical durability, and corrosion resistance in laboratory and industrial environments

Sample Compatibility & Compliance

The HY-BH26/HY-BH22 series is designed for integration into 2.45 GHz microwave systems using standard WR-340 (BJ-26) or WR-430 (BJ-22) waveguide infrastructure. It supports both magnetron-driven and solid-state RF sources, and is compatible with common microwave processing equipment—including plasma reactors, material sintering chambers, and industrial heating cavities. While not certified to IEC 61000-4-x immunity standards as a standalone component, the circulator meets mechanical and RF interface requirements per IEEE Std 157-2020 (Standard Test Procedures for Waveguide Components) and conforms to RoHS Directive 2011/65/EU for hazardous substance restrictions. System-level compliance with FCC Part 18 or EN 55011 Class A emissions limits depends on full-system integration and shielding design.

Software & Data Management

This is a purely passive RF component with no embedded electronics, firmware, or digital interfaces. No software drivers, configuration utilities, or data logging capabilities are provided or required. Performance verification is conducted using vector network analyzers (e.g., Keysight PNA series) calibrated per ISO/IEC 17025-accredited procedures. Users are advised to document insertion loss, isolation, and VSWR measurements during installation and periodic maintenance to support GLP-compliant system validation protocols. Traceable calibration certificates for associated test equipment may be requested separately from accredited metrology laboratories.

Applications

• Isolation of 2.45 GHz magnetrons in industrial microwave heating systems to prevent damage from cavity reflections
• Reflected power routing in plasma generation systems (e.g., ICP, CCP), where impedance instability demands real-time load absorption
• Protection of solid-state RF amplifiers in scientific instrumentation such as electron cyclotron resonance (ECR) sources and microwave-assisted chemistry reactors
• Test bench configurations requiring directional power monitoring or dual-load switching without manual re-cabling
• High-reliability RF subsystems in aerospace ground support equipment and defense-related EW simulation platforms

FAQ

What cooling water specifications are required for safe operation?
Deionized water with resistivity ≥1 MΩ·cm, flow rate ≥3 L/min, inlet temperature 10–25 °C, and pressure drop <1.2 bar across the load. Use non-ferrous tubing and avoid glycol mixtures unless validated for thermal conductivity and corrosion compatibility.

Can this circulator operate at frequencies other than 2.45 GHz?
No. The ferrite resonator and waveguide dimensions are tuned specifically for 2.45 GHz ISM band operation. Off-frequency use results in degraded isolation, elevated VSWR, and potential thermal overload.

Is the water load replaceable or serviceable in the field?
The water load is permanently sealed and not user-serviceable. Replacement requires factory recalibration and magnetic alignment verification; field disassembly voids warranty and compromises RF performance.

Does the device meet FDA or ISO 13485 requirements for medical device applications?
The unit itself carries no medical device classification. Integration into FDA-regulated systems (e.g., microwave ablation generators) requires full system-level design control, risk analysis per ISO 14971, and verification under IEC 60601-2-95.