Abstract : Network analyzers provide a fast and accurate measurement method for frequency converters. Based on the measurement principles of scalar network analyzers and vector network analyzers, this paper details the method of measuring frequency converter losses using a scalar network analyzer and the method of measuring frequency converter losses and phase using a vector network analyzer. The applicable scope and advantages and disadvantages of the two instruments in frequency converter measurement are analyzed. Taking a quadrature mixer as an example, a network analyzer measurement method for measuring its amplitude imbalance and phase imbalance is provided; taking a special application where the local oscillator and RF signal frequency ranges coincide as an example, a simple and accurate measurement method is introduced. Keywords: Frequency converter; scalar network analyzer; vector network analyzer; amplitude-frequency characteristic; phase-frequency characteristic 1 Introduction Mixers are key components in radio frequency (RF) and microwave systems, commonly used in down-conversion, up-conversion, and quadrature conversion applications. Broadly speaking, these devices and components that can realize frequency conversion functions are collectively referred to as frequency converters. Typical RF and microwave devices, such as amplifiers, power dividers, and filters, have the same input and output signal frequencies. Inverters, however, are three-port devices with local oscillator (ID), radio frequency (RF), and intermediate frequency (IF) ports. Driven by the local oscillator power, they convert RF signals to IF signals (down-conversion) or IF signals to RF signals (up-conversion). The signal frequencies of the three ports satisfy the relationship: F_IF = mF_RF + nF_LO (where m and n are integers). Because the input and output frequencies of inverter devices are not equal, their measurement is more complex than that of other devices. Network analyzers are commonly used measurement instruments in RF and microwave systems, and are divided into scalar network analyzers (hereinafter referred to as scalar network analyzers) and vector network analyzers (hereinafter referred to as vector network analyzers). These two types of network analyzers have different testing principles, but both can be used to test inverter devices. Scalar network analyzers can measure inverter conversion losses, output power, return loss, and isolation, among other things. Vector analytic converters (VACs) with frequency offset capabilities can measure not only parameters that can be measured using standard analytic converters, but also phase-related parameters such as phase and group delay. However, VAC measurement instruments are complex to configure and require cumbersome preparation. Standard analytic converter instruments are simple to configure and introduce fewer error terms during measurement. Therefore, flexibly selecting the test method according to the actual situation can accurately and easily obtain various parameters of frequency converters. [align=center][b]For more details, please click: Application of Network Analyzer in Frequency Converter Measurement[/b][/align]