The Agilent E4991A is a high-performance RF impedance/material analyzer primarily used for accurately measuring the impedance characteristics of RF components and materials. Below is a detailed introduction:

- Key Performance Parameters: Utilizes RF-IV technology with a basic impedance accuracy of ±0.8%. The internal frequency synthesizer can scan within a frequency range of 1MHz to 3GHz with a resolution of 1mHz, and an oscillator level as high as 1dBm/0.5Vrms/10mArms.
- Functional Features: Equipped with an 8.4-inch TFT color LCD, capable of displaying up to 5 curves, 9 markers, and 801 sweep points. Features marker analysis and marker limit functions to reduce testing time, and includes equivalent circuit analysis, allowing easy component modeling using 5 different multi-parameter models. Additionally, it supports various interfaces, including LAN, GPIB, USB, etc., facilitating connection with other devices and data transfer. Built-in Visual Basic for Applications (VBA) programming capability enables automated programming and data storage.
- Measurement Options: Dielectric/Magnetic Material Measurement Option E4991A-002 provides a comprehensive dielectric/magnetic material measurement solution across a wide frequency range of 1MHz to 1GHz; On-Wafer Measurement Option E4991A-010 allows the instrument to connect to Cascade Microtech's RF probe systems via a probe station connection kit for on-chip impedance measurements; Temperature Characteristic Measurement Option E4991A-007 offers high-precision temperature characteristic analysis capability across a wide temperature range from -55°C to +150°C, with robust temperature drift compensation.
- Application Areas: Primarily used for evaluating components within the 3GHz range, suitable for scenarios such as R&D, quality assurance, and inspection. It can be applied to measure the electrical performance of high-frequency devices like antennas and filters, as well as for characterizing and evaluating surface mount devices (SMDs) and dielectric/magnetic materials.