HP / Agilent 85020A RF directional bridge, 50 ohm, Type N

The HP/Agilent 85020A is a 50-ohm RF directional bridge designed for scalar reflection and transmission measurements in network analyzer systems. It integrates a zero-bias Schottky diode detector for direct return loss sampling, eliminating the need for external detection during reflection measurements. The device operates from 10 MHz to 4.3 GHz with directivity of 40 dB below 3 GHz and 34 dB from 3 to 4.3 GHz.

Port match remains excellent across the full frequency range, with VSWR of 1.20 below 3 GHz and 1.25 up to 4.3 GHz. Type-N female connectors provide standardized RF interfaces at both input and test ports.

Technical Specifications

• Frequency Range: 10 MHz to 4.3 GHz


• Nominal Impedance: 50 ohms


• Directivity: 40 dB (10 MHz to 3 GHz); 34 dB (3 GHz to 4.3 GHz)


• Port Match (VSWR): 1.20 (10 MHz to 3 GHz); 1.25 (3 GHz to 4.3 GHz)


• Maximum Input Power: +23 dBm


• Detector: Zero-bias Schottky diode


• Connectors: Type-N female (input and test ports)

Key Features

• Integrated zero-bias Schottky diode eliminates external detector requirement for reflection measurements


• Configurable for transmission measurements with external detector integration


• High directivity maintains measurement accuracy across broad frequency span


• Consistent port match minimizes systematic error in scalar measurements

Typical Applications

• Return loss characterization of passive and active components


• Impedance and reflection coefficient measurement


• Transmission measurement systems with external detector


• Component validation and quality assurance in RF production environments

Compatibility & Integration Designed for integration with HP 8756A, 8755C, and 8757 scalar network analyzers. Supports system configurations using swept signal sources (HP 8350B Sweep Oscillator), external detectors (HP 11664A), and power splitters (HP 11667A/B) for ratio-based measurements. Compatible with 85023-series System Verification Sets for test system validation.