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Using Varactor Diodes for FM Signal Generation

Using Varactor Diodes for FM Signal Generation

Learn how a varactor diode's variable capacitance, together with an LC tank circuit, can drive a voltage-controlled oscillator (VCO) to create FM waveforms.


An FM Generator Circuit Using the Capacitance of a Collector-Base Junction

An FM Generator Circuit Using the Capacitance of a Collector-Base Junction

In this article, we examine a reactance modulator design that employs the variable capacitance of a bipolar junction transistor to modulate the output of a Colpitts oscillator.


Introduction to Reactance Modulators for Generating FM Signals

Introduction to Reactance Modulators for Generating FM Signals

In this article, we'll introduce the fundamental concepts of direct FM generation and examine a key FM modulation circuit: the reactance modulator.


Estimating FM Bandwidth: Solved Examples

Estimating FM Bandwidth: Solved Examples

In this article, we'll illustrate the usefulness of Carson's rule for bandwidth estimation by working through a series of example problems.


Exploring the Relationship Between FM Wave Bandwidth and the Modulation Index

Exploring the Relationship Between FM Wave Bandwidth and the Modulation Index

In this article, we'll investigate how varying the amplitude and frequency of the modulating tone impacts the bandwidth of FM signals. We'll also compare the modulation index in AM and FM schemes.


Three Methods for Estimating the Transmission Bandwidth of FM Signals

Three Methods for Estimating the Transmission Bandwidth of FM Signals

Along with introducing Carson's rule for bandwidth estimation, this article explains how to calculate the required transmission bandwidth based on either the sidebands or the total power of the signal.


Exploring Bessel Functions: Understanding the Spectrum of Tone-Modulated FM

Exploring Bessel Functions: Understanding the Spectrum of Tone-Modulated FM

In this article, we’ll learn about the essential properties of Bessel functions and what they can tell us about the bandwidth of practical FM signals.


Introduction to Wideband FM Signals

Introduction to Wideband FM Signals

Learn how Bessel functions and the modulation index can help us understand the bandwidth of wideband frequency-modulated (FM) signals.


Dynamic Nonlinearity in RF Power Amplifiers: Insights From Two-Tone Testing

Dynamic Nonlinearity in RF Power Amplifiers: Insights From Two-Tone Testing

This article explores the effect of signal bandwidth on the linearity of power amplifiers, including the impacts of cascaded RF gain stages.


Practical Insights Into Narrowband FM With a Single-Frequency Input

Practical Insights Into Narrowband FM With a Single-Frequency Input

In this article, we’ll use phasor diagrams to compare narrowband FM and conventional AM. We’ll also discuss the problem of oscillator phase noise and work through an example problem.


Understanding the Third-Order Intercept Point of a Cascaded System

Understanding the Third-Order Intercept Point of a Cascaded System

Using the third-order intercept point (IP3) metric, we examine how the nonlinearity of individual gain stages in a cascaded RF system affects the linearity performance of the cascade as a whole.


Introduction to Narrowband Angle Modulation

Introduction to Narrowband Angle Modulation

Using a simple example, this article examines the frequency spectra of frequency-modulated (FM) and phase-modulated (PM) waves for a low modulation index.


Carbon-Capture ‘Mars’ Batteries Move Closer to Reality

Carbon-Capture ‘Mars’ Batteries Move Closer to Reality

Scientists boosted lithium-carbon dioxide batteries’ performance and life cycle, showing promise for use on Mars and Earth.


News Jun 13, 2025 by Kevin Clemens
Understanding the Differences Between Phase and Frequency Modulation

Understanding the Differences Between Phase and Frequency Modulation

Learn why phase modulation (PM) and frequency modulation (FM) can produce waveforms that are nearly identical or completely different from one another, depending on the nature of the message signal.


A Guide to Calculating IM3 and IP3 for Nonlinear RF Circuits

A Guide to Calculating IM3 and IP3 for Nonlinear RF Circuits

Learn to confidently determine intermodulation distortion products and the third-order intercept point of RF circuits by working through a selection of example problems.


Startup Intros ‘Most Advanced’ Multi-Gigahertz Timing and Clock Devices

Startup Intros ‘Most Advanced’ Multi-Gigahertz Timing and Clock Devices

Unveiled today, the new timing chips from Mixed-Signal Devices offer 2 GHz performance and use scalable CMOS to overcome the limits of analog alternatives.


News Jun 03, 2025 by Jeff Child
Using Instantaneous Frequency to Represent PM and FM Signals

Using Instantaneous Frequency to Represent PM and FM Signals

In this article, we’ll explore the mathematical relationship between phase modulation (PM) and frequency modulation (FM). We’ll then learn how a PM modulator can be used to generate FM signals, and vice versa.


Understanding Intermodulation Distortion and the Third-Order Intercept Point In RF Systems

Understanding Intermodulation Distortion and the Third-Order Intercept Point In RF Systems

Learn how the two-tone input test helps us evaluate the nonlinearity of RF systems operating on real-world signals.


3 New Power MOSFETs Offer Improved System Performance

3 New Power MOSFETs Offer Improved System Performance

The latest devices from Microchip, Rohm, and SemiQ offer enhanced radiation protection, increased operation range, lower conduction losses, and faster switching frequencies.


News May 16, 2025 by Jake Hertz
Phoenix Contact ArcZero Series DC Connectors | Digital Datasheet

Phoenix Contact ArcZero Series DC Connectors | Digital Datasheet

Phoenix Contact ArcZero Series DC Connectors offer arc-free, load-safe connectivity with tool-free locking for quick, low-maintenance operation. Watch and learn all about their features, specs, applications, and more!