Articles

RSS

By Gary Simpson, David Ballo, Joel Dunsmore, Amar Ganwani

Abstract — A new method for noise parameter measurements is introduced, with better than 100x speed improvement over traditional methods. The setup is simple and easy to configure, and the entire calibration and measurement process is very fast, making dense frequency spacing practical. The new method produces smoother data with lower scatter, and the dense frequency spacing eliminates shifts due to aliasing and makes it easier to identify the scatter and outliers.

Introduction

Noise occurs naturally in any active device or circuit, and limits the minimum levels of useful signals. With a cell phone, for example, it can interfere with a weak signal, and interrupt a call. Therefore, it is important to design circuits to minimize the effects of noise. To do this, the noise must be quantified and measured.

The most common measure of added circuit noise is a figure-of-merit called noise figure, which quantifies the signal-to-noise degradation caused by an amplifier. While noise figure is most commonly measured in a 50-ohm environment, a device's noise figure varies with the source impedance presented to the device. This variation can be expressed in terms of noise parameters, which are essential to know when designing low-noise amplifiers using highly mismatched devices.

Click Here To Download:
•Application Note: A New Noise Parameter Measurement Method Results In More Than 100x Speed Improvement And Enhanced Measurement Accuracy