VNA Mode | Type | Parameters Calibrated | Uses |
2-Port VNA Mode | Full 2-Port | S11, S12, S21, and S22 | Most complete calibration |
Full 1-Port | S11 or S22 | Reflection calibration only | |
1-Path 2-Port | S11 and S21 or S22 and S12 | 1-port reflection plus simple transmission (faster, lower transmission accuracy unless DUT very lossy) | |
Frequency Response | Any one parameter (or pairs of symmetric parameters such as S12 and S21) | Normalization only. Fast, lower accuracy | |
4-Port VNA Mode | When in 4-Port mode, additional calibration types of 4-Port and 3-Port become available in the CALIBRATION menus with an associated expansion of S-Parameters, User-Defined, and Mixed-Mode options in the RESPONSE menus. |
Calibration Algorithm | Description | Advantages | Disadvantages |
---|---|---|---|
SOLT (Short-Open-Load-Through) | Common coaxially | Simple, redundant standards; not band-limited | Requires very well-defined standards, poor on-wafer, lower accuracy at high frequencies |
SSLT (Short-Short-Load-Through, also called Offset Short), shorts with different offset lengths | Common in waveguide | Same as SOLT | Same as SOLT and band-limited |
SSST (Short-Short-Short-Through, also called Triple Offset Short), all shorts with different offset lengths | Common in waveguide or high frequency coax | Same as SOLT but better accuracy at high frequencies | Requires very well-defined stds, poor on-wafer, band-limited |
SOLR/SSLR/SSSR, like above but with “Reciprocal” instead of “Through” | Like the above but when a good through is not available | Does not require well-defined through | Some accuracy degradation but slightly less definition, other disadvantages of parent cal |
Broadband Calibration SOLT/SOLR-SSST/SSSR | Combines SOLT/R and SSST/R in a single calibration (SOL below an entered frequency and SSS above it). | Saves time and connections when doing a broadband cal (no need to merge). Simple, redundant standards. Not as band-limited as constituents. | Requires very well-defined standards. Generally poor on-wafer. |
LRL (Line-Reflect-Line; also called TRL) | High performance coax, waveguide, or on-wafer | Highest accuracy, minimal standard definition | Requires very good transmission lines, less redundancy so more care is required, band-limited |
ALRM, advanced line-reflect-match, simplifies to LRM (Line-Reflect-Match) or TRM (Through-Reflect-Match) | Relatively high performance | High accuracy, only one line length so easier to fixture/on-wafer, not band-limited usually | Requires load definition. Reflect standard setup may require care depending on load model used |
mTRL (Multiline TRL) | High performance coax, waveguide, or on-wafer | Highest accuracy, minimal standard definition | Requires very good transmission lines, uses up to 10 lines and all lines are used at all frequencies in a least-squares sense so it more seamlessly deals with band limitation. Usually requires more lines than LRL for best performance. |
VNA Mode | Type | SOLT | SSLT | SSST | SOLR/SSLR /SSSR | Broadband SOLT/R-SSST/R | LRL | ALRM | mTRL | mSSS |
---|---|---|---|---|---|---|---|---|---|---|
2-Port Mode | Full 2-Port | YES | YES | YES | YES | YES | YES | YES | YES | YES |
Full 1-Port | YES | YES | YES | Can be selected for these types, but the reciprocal nature is not used and will function like the base calibration. | YES | – | – | – | YES | |
1-Path 2-Port | YES | YES | YES | – | – | – | – | YES | ||
Frequency Response | YES | YES | YES | – | – | – | – | – | ||
4-Port Mode | The calibration types and modes change when the VNA is in multiport (4-Port) mode. See Multiport Measurements for a discussion of multiport calibration methods and types. |