The Agilent/Keysight 85072A is a 10 GHz split cylinder resonator for non-destructive measurement of dielectric properties in flat, solid sheet materials and liquids. It measures complex permittivity and loss tangent with high accuracy by operating as a resonant cavity, requiring integration with a Keysight vector network analyzer, cables, and resonant cavity software.
Technical Specifications
Operating Frequency
• Nominal operating frequency: 10 GHz
• TE₀₁₁ resonant mode: 10.03 ± 0.03 GHz
• Q factor ≥ 20,000 (with input coupling at -50 dB)
Measurement Accuracy
• TE₀₁₁ mode — Real part of permittivity: ±1%; Loss tangent: ±0.0001
• Higher order TE₀ₙₚ modes — Real part of permittivity: ±1% to 2%; Loss tangent: ±0.0005
Sample Specifications
• Thickness range: 0.1 mm to 3 mm (typical 1 mm); samples up to 5 mm fit with degraded accuracy
• Minimum dimension: 56 mm length or diameter; 60 mm or greater recommended
• Material requirements: Non-magnetic (μᵣ = 1-j0), homogeneous, isotropic
• Geometry: Uniform thickness with flat, parallel sides
• Recommended limits for 1 mm samples: ε’ < 100, tan δ < 0.01
– Key Features
• Split cylinder design with one fixed and one adjustable half for variable sample thickness accommodation
• Diamond-turned copper and gold-plated aluminum construction with kinematic mount for precise alignment
• Integrated digital micrometer for accurate sample thickness measurement
• Coupling loops on side holes for TE₀ₙₚ mode measurement
• Electric field oriented parallel to sample, perpendicular to cylinder z-axis
• High Q cavity optimized for low-loss material characterization
• Complies with IPC test method TM-650 2.5.5.13
– Typical Applications
• Dielectric property measurement of thin film and un-clad substrates
• Low-loss sheet material characterization
• PCB material and laminate evaluation
– Compatibility & Integration
Requires Keysight vector network analyzer, associated measurement cables, and resonant cavity software for complete system operation.
