Explore how frequency-modulated waves resist interference. We break down the demodulator architecture and derive the exact output signal power for a sinusoidal message.
Explore how frequency-modulated waves resist interference. We break down the demodulator architecture and derive the exact output signal power for a sinusoidal message.
Envelope detection is simple, but that simplicity has a noise-performance cost. Here’s how much SNR conventional AM…
Envelope detection is simple, but that simplicity has a noise-performance cost. Here’s how much SNR conventional AM gives up compared to its coherent counterparts.
Using a graphical approach, we show that coherent SSB demodulation leaves the input and output SNR unchanged, then…
Using a graphical approach, we show that coherent SSB demodulation leaves the input and output SNR unchanged, then compare its noise performance to DSB-SC and baseband systems.
Visualizing how correlated and uncorrelated signals combine offers an intuitive look at power transformation. See how…
Visualizing how correlated and uncorrelated signals combine offers an intuitive look at power transformation. See how this difference boosts baseband power to double the output SNR.
In this article, we'll learn how to calculate the noise power and signal-to-noise ratio (SNR) of a double-sideband…
In this article, we'll learn how to calculate the noise power and signal-to-noise ratio (SNR) of a double-sideband suppressed-carrier communication system.
This article explores the operation of the Gilbert-cell phase detector for both small and large signals.
This article explores the operation of the Gilbert-cell phase detector for both small and large signals.
Learn how using a pole-zero loop filter improves PLL performance and design flexibility over the simpler lag filter.
Learn how using a pole-zero loop filter improves PLL performance and design flexibility over the simpler lag filter.
In this article, we analyze the steady-state errors and Bode plots for a second-order PLL with a simple, first-order loop filter.
In this article, we analyze the steady-state errors and Bode plots for a second-order PLL with a simple, first-order loop filter.
Learn how adding a lowpass loop filter to a PLL with a single integrator impacts both the frequency-domain and…
Learn how adding a lowpass loop filter to a PLL with a single integrator impacts both the frequency-domain and time-domain response.
In this article, we'll use the linearized model of a first-order PLL to understand its response to a simple input change.…
In this article, we'll use the linearized model of a first-order PLL to understand its response to a simple input change. We'll then use Matlab simulations to visualize the signals.
In this article, we'll use a nonlinear mathematical model to improve our understanding of how a first-order PLL locks to a signal.
In this article, we'll use a nonlinear mathematical model to improve our understanding of how a first-order PLL locks to a signal.
In this article, we'll solidify our understanding of the reactance modulator and Armstrong modulator circuits by working…
In this article, we'll solidify our understanding of the reactance modulator and Armstrong modulator circuits by working through a series of design problems.
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.
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 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.