RF Phase Noise Analyzer Manufacturers | VCO Tester

This page covers RF Phase Noise Analyzer Manufacturers or Vendors used for VCO testing. The popular manufacturers of VCO testers to check their phase noise include Rohde & Schwarz, Keysight, Microsemi, Holzworth Instrumentation, and Berkeley Nucleonics Corporation.

Introduction

Various RF parameters are used during the testing of transmitter and receiver parts of RF devices and components. Phase noise is a very important parameter. It is measured at the transmitter output of the DUT (Device Under Test), which can be LOs, VCOs, PLLs, etc.

What is VCO?

VCO is the short form of Voltage Controlled Oscillator. It generates an output frequency based on an applied input voltage. There are many applications of VCOs, which include function generators, PLLs, synthesizers, fixed LOs (Local Oscillators), variable LOs, frequency modulators, etc.

The following specifications are considered before selecting a VCO for your design:

• Operating Frequency range
• DC tuning voltage range
• Output power
• Phase Noise
• Vcc/Icc
• Pushing and Pulling
• Tuning speed
• Package type

The figure depicts the position of a VCO in a PLL (Phase Locked Loop) circuit. VCOs are categorized into tuned oscillator and untuned oscillator types.

What is Phase Noise?

Phase noise is used as a purity measurement of VCOs, synthesizers, and crystal oscillators. Phase noise is measured using different techniques by various test equipment. The most common method is using a spectrum analyzer as shown. It is measured at some distance away from the desired carrier frequency, e.g., 10 Hz, 100 Hz, 1 KHz, 10 KHz, etc. It is measured in units of dBc/Hz. It is basically the ratio of signal to noise power in a 1 Hertz bandwidth.

The figure depicts phase noise measurement using a spectrum analyzer. As shown, phase noise is measured using the following simple calculation and power levels measured on the spectrum analyzer.

Where:

• “D” is the difference between the instantaneous power of the desired frequency and the sideband frequency (@1KHz or any other spacing).
• RBW is the Resolution Bandwidth.

The figure depicts a simple test setup of phase noise measurement using an RF spectrum analyzer.

RF Phase Noise Analyzer Manufacturers

The following table lists popular manufacturers of RF Phase Noise Analyzers. This test equipment is very useful to characterize sources such as VCOs, DROs, Synthesizers, and OCXOs. The test and measurement equipment is used for various applications such as satellite and radar in various frequency bands such as C band, Ku band, X band, K band, etc.