Keysight (Agilent) 33330B Low-Barrier Schottky Diode Detector, 0.01 to 18 GHz

The Keysight (Agilent) 33330B is a broadband coaxial detector employing a Low Barrier Schottky (LBS) diode for RF signal detection across 0.01 to 18 GHz. Designed for leveling loops, power monitoring, and wideband video detection in microwave instrumentation, the 33330B requires no external bias and delivers superior performance compared to conventional Schottky diodes, tunnel diodes, and point-contact diodes. The detector integrates the LBS diode with supporting circuit elements via miniature thin-film construction, minimizing stray reactances to achieve excellent broadband flatness and repeatability.

Technical Specifications

• Frequency Range: 0.01 to 18 GHz


• Frequency Response Flatness: ±0.3 dB from 0.01 to 12.4 GHz; ±0.6 dB from 0.01 to 18 GHz; octave band flatness ±0.2 dB to 8 GHz


• Standing Wave Ratio (SWR): 1.20 or less from 0.01 to 4 GHz; 1.50 or less from 0.01 to 18 GHz


• Low Level Sensitivity: > 0.5 mV/µW


• Noise: < 50 µV peak-to-peak (CW power generating 100 mV output, 400 kHz BW)


• Output Impedance: 50 ohms


• Maximum Operating Input Power: 200 mW


• Short-Term Maximum Input Power: 1 W (< 1 minute)


• Output Polarity: Negative (default); positive available with Option 003


• Weight: 14 g

Key Features

• Low Barrier Schottky diode with low origin resistance and low junction capacitance


• Bias-free operation simplifies integration and reduces complexity


• APC 3.5-mm male RF input connector (SMA compatible) provides superior repeatability versus SMA


• SMC male video output connector


• Matched pair option (Option 001) tracks within ±0.5 dB across full frequency range; ±0.2 dB from 0.01 to 12.4 GHz and ±0.3 dB from 0.01 to 18 GHz


• Withstands 1 watt CW for up to one minute without permanent damage


• Metallurgical diode bonds and MIL-STD 883 environmental testing ensure ruggedness

Typical Applications

• Power leveling and feedback loops


• RF/microwave power monitoring


• Broadband video detection


• Microwave instrumentation and systems integration

Compatibility & Integration RF input accepts APC 3.5-mm male connectors. Video output delivered via SMC male connector; RF may leak below 1 GHz without additional low-pass filtering.