#403: Measuring a Directional Coupler with a SV4401A VNA @w2aew

Uploaded September 2025 | Updated September 2026, 2 weeks ago

This video shows the process of setting up, calibrating and using a SV4401A Vector Network Analyzer to characterize the Return Loss (Reflection Coefficient), VSWR, Mainline Loss (Transmission Coeff), Coupling Ratio and Directivity of a Mini-Circuit ZFDC-20-5+ directional coupler over a 100kHz to 2GHz frequency range.
00:00 Introduction
00:28 Review of Measurements of a Directional Coupler
02:14 Specifications of the Mini Circuit ZFDC-20-5+
03:53 Setup VNA Frequency Range
04:17 Calibration Considerations
05:17 Calibration Process
07:00 Setup for Return Loss (reflection coefficient S11) and SWR
08:25 Validate the test terminations
09:52 Making the S11/Return Loss/SWR measurements
11:34 Mainline Loss Measurements
13:05 Measuring Coupling Ratio
14:18 Setup for Directivity with Reference trace
15:39 Marker setup
17:20 Directivity Calculation
18:23 Wrap-up

#403: Measuring a Directional Coupler with a SV4401A VNA

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