This article explores the concept of indirect FM generation and the basic operation of the Armstrong modulator.
This article explores the concept of indirect FM generation and the basic operation of the Armstrong modulator.
In this article, we examine two different methods of producing wideband FM signals. Both use crystal oscillators to…
In this article, we examine two different methods of producing wideband FM signals. Both use crystal oscillators to provide improved frequency stability.
In this article, we explore the limitations of LC oscillators for direct FM generation and how to deal with them using…
In this article, we explore the limitations of LC oscillators for direct FM generation and how to deal with them using multipliers and automatic frequency control (AFC) circuits.
Learn how a varactor diode's variable capacitance, together with an LC tank circuit, can drive a voltage-controlled…
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.
In this article, we examine a reactance modulator design that employs the variable capacitance of a bipolar 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.
In this article, we'll introduce the fundamental concepts of direct FM generation and examine a key FM modulation…
In this article, we'll introduce the fundamental concepts of direct FM generation and examine a key FM modulation circuit: the reactance modulator.
This article explores the effect of signal bandwidth on the linearity of power amplifiers, including the impacts of…
This article explores the effect of signal bandwidth on the linearity of power amplifiers, including the impacts of cascaded RF gain stages.
In this article, we’ll use phasor diagrams to compare narrowband FM and conventional AM. We’ll also discuss the…
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.
Using the third-order intercept point (IP3) metric, we examine how the nonlinearity of individual gain stages in a…
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.
Using a simple example, this article examines the frequency spectra of frequency-modulated (FM) and phase-modulated (PM)…
Using a simple example, this article examines the frequency spectra of frequency-modulated (FM) and phase-modulated (PM) waves for a low modulation index.
Gain compression causes power systems to transition from linear to nonlinear operation. Learn how the 1 dB compression…
Gain compression causes power systems to transition from linear to nonlinear operation. Learn how the 1 dB compression point is used to define the limits of linear operation.
Learn about the Weaver modulator, an RF circuit that improves on older forms of SSB modulation by removing the need for…
Learn about the Weaver modulator, an RF circuit that improves on older forms of SSB modulation by removing the need for either sharp bandpass filters or quadrature phase shifters.
We explore the basic concepts of analog predistortion for linearizing RF amplifiers and review some common implementations.
We explore the basic concepts of analog predistortion for linearizing RF amplifiers and review some common implementations.
Learn about a classic amplitude modulation (AM) technique that’s been used in voice transmission for nearly a century.
Learn about a classic amplitude modulation (AM) technique that’s been used in voice transmission for nearly a century.
Learn about an important design technique for high-power RF transmitters: feed-forward linearization, which operates on…
Learn about an important design technique for high-power RF transmitters: feed-forward linearization, which operates on the principle of distortion signal cancellation.
We examine RF demodulation circuits used for both double-sideband suppressed carrier (DSB-SC) signals and double-sideband…
We examine RF demodulation circuits used for both double-sideband suppressed carrier (DSB-SC) signals and double-sideband signals with a carrier.
This article highlights a selection of circuits used for amplitude modulation, including a switching modulator built with…
This article highlights a selection of circuits used for amplitude modulation, including a switching modulator built with just one diode and a circuit that incorporates a Class C power amplifier.
Learn how the balanced modulator addresses shortcomings of the square-law modulator when generating DSB-SC and…
Learn how the balanced modulator addresses shortcomings of the square-law modulator when generating DSB-SC and conventional AM signals.
In this project article, we'll use a 555 timer IC to build an iconic musical instrument from the early days of synthesizers.
In this project article, we'll use a 555 timer IC to build an iconic musical instrument from the early days of synthesizers.
In this article, we discuss a tuning method designed specifically for Class E RF amplifiers.
In this article, we discuss a tuning method designed specifically for Class E RF amplifiers.