Calibration and RF Measurements using a VNA Siglent SNA5000A- 4 ports
April 23, 2023
The following are some recommended common practices when performing any RF measurement.
1. Use good quality RF cables. Double shielded with tin foil is recommended for phase stability and isolation.
2. Use properly power rated RF cables.
3. Use properly frequency rated connector type.
a. BNC type is rarely used above 500 MHz sense they do not provide a secure connection. Very leaky and repeatability of measurement is difficult. Avoid using above 100 MHz.
b. See table below as guidance. ( https://www.arworld.us/resources/Guide-to-RF-Coaxial-Connectors-and-Cables.asp).
4. Use correct mating types with connectors and adaptors
a. See table below as guidance. (https://na.support.keysight.com/pna/connectorcare/What_mates_with_what.htm )
5. Use a torque wrench as per specification.
6. Calibration and measurement – let the cables rest in a natural state with no sharp bends.
a. Secure cables (with tape) to avoid moving them during the calibration/measurement and for repeatability.
7. When making connections, never turn the load by spinning it. Turn the fitting which will “pull” the load in thus “pushing” the center pin into the female load pin. Spinning the mating will damage the center pins of both connections.
8. Clean all connectors and adaptors with isopropyl alcohol and lint free cloth or swab.
9. Avoid noisy RF environments when making sensitive measurements that require large dynamic ranges.
