Network Analyzer: Advantages and Disadvantages

This page explores the pros and cons of different types of network analyzers, specifically focusing on Scalar Network Analyzers (SNA) and Vector Network Analyzers (VNA). Network analyzers are essential instruments for making both transmission and reflection measurements. Transmission measurements involve parameters like transmission coefficient, insertion loss, and gain. Reflection measurements, on the other hand, cover reflection coefficient, return loss, and impedance.

Figure 1: Shows an SNA model (8757D) and a VNA model (E5072A).

As the names suggest, a Scalar Network Analyzer (SNA) measures only the magnitude of signals, while a Vector Network Analyzer (VNA) measures both the magnitude and phase. Let’s dive into the specific advantages and disadvantages of each type.

Advantages of Scalar Network Analyzer (SNA)

Here’s a look at the benefits offered by SNAs:

• Simpler Hardware: The hardware required for down conversion and power detection is relatively simple in an SNA.
• Cost-Effective: Due to their simpler design, SNAs are generally more affordable than VNAs.
• Faster Sweeps: SNAs can perform measurement sweeps more quickly compared to VNAs.

Disadvantages of Scalar Network Analyzer (SNA)

Here are the drawbacks of using an SNA:

• No Phase Measurements: SNAs cannot measure the phase of signals, limiting their use in applications where phase information is crucial.

Advantages of Vector Network Analyzer (VNA)

Here are the benefits of using VNAs:

• Magnitude and Phase Measurements: VNAs can measure both the magnitude and phase of signals, offering comprehensive characterization capabilities.

Disadvantages of Vector Network Analyzer (VNA)

Here are some drawbacks associated with using VNAs:

• Slower Sweeps: VNAs tend to perform measurement sweeps more slowly than SNAs.
• Complex Design: VNAs are considerably more complex than SNAs due to the use of a full heterodyne architecture in their receiver section. This complexity is necessary for measuring both magnitude and phase.
• Higher Cost: Due to their complex design, VNAs are more expensive than SNAs.