Agilent/Keysight 85072A

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

• 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.