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Evaluating SNR Performance of FMFB Demodulators at High CNR

Evaluating SNR Performance of FMFB Demodulators at High CNR

While feedback lowers the FM detection threshold, it offers no noise advantage over conventional receivers when the carrier power is strong. Discover why in this discussion and mathematical analysis.


FM Demodulation with Feedback: Exploring Threshold Reduction Mechanisms

FM Demodulation with Feedback: Exploring Threshold Reduction Mechanisms

By closing a feedback loop around the demodulator, the FMFB architecture narrows the noise bandwidth and lowers the FM threshold, without improving SNR at high CNR.


Build an Instrumentation Amplifier with Picoamp-Level Input Bias Current

Build an Instrumentation Amplifier with Picoamp-Level Input Bias Current

Discover how the LT1079 quad op-amp minimizes sensor loading in battery-powered designs. Active cancellation and an onboard bridge network ensure maximum precision for resistive sensors.


Exploring the Threshold Constraints of FM Demodulation Through Solved Examples

Exploring the Threshold Constraints of FM Demodulation Through Solved Examples

Working through examples shows how the threshold effect reshapes FM design choices. See how ignoring it can undershoot the required carrier power by over 5x for the same target SNR.


Arduino-Compatible RS-485 Linear Hall Sensor Board for Magnetic Field Sensing

Arduino-Compatible RS-485 Linear Hall Sensor Board for Magnetic Field Sensing

This project brief describes how to build and use an Arduino-compatible board that reads a linear Hall-effect sensor and reports the measurement over an RS-485 bus.


Introduction to the Threshold Effect in FM Systems

Introduction to the Threshold Effect in FM Systems

The standard FM SNR equation breaks down once the carrier-to-noise ratio drops below a critical threshold, revealing a hard limit on trading bandwidth for noise performance.


SNR Analysis of FM Modulation with Arbitrary Message Signals

SNR Analysis of FM Modulation with Arbitrary Message Signals

Deriving a general signal-to-noise expression for frequency modulation with any message signal reveals a core trade-off: more deviation buys better noise performance, but only by using more bandwidth.


Understanding Noise in FM Systems: The Tone-Modulated Scenario, Part 2

Understanding Noise in FM Systems: The Tone-Modulated Scenario, Part 2

This article explores how combining signal and noise power reveals how the FM system’s output SNR scales with carrier amplitude and modulation index.


Understanding Noise in FM Systems: The Tone-Modulated Scenario, Part 1

Understanding Noise in FM Systems: The Tone-Modulated Scenario, Part 1

Explore how frequency-modulated waves resist interference. We break down the demodulator architecture and derive the exact output signal power for a sinusoidal message.


Understanding the Noise Performance of AM Receivers with Envelope Detection

Understanding the Noise Performance of AM Receivers with Envelope Detection

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.


Analyzing the Noise Performance of Coherent SSB Demodulators

Analyzing the Noise Performance of Coherent SSB Demodulators

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.


A Four-Channel RS-422 Differential Line Receiver Module

A Four-Channel RS-422 Differential Line Receiver Module

This project brief describes how to build and use a four-channel differential line receiver module for balanced RS-422 and RS-485 data links.


Understanding SNR in DSB‑SC Coherent Detection: A Graphical Approach

Understanding SNR in DSB‑SC Coherent Detection: A Graphical Approach

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.


A Four-Channel RS-422 Differential Line Driver Module

A Four-Channel RS-422 Differential Line Driver Module

This project brief describes how to implement a four-channel differential line driver module for reliable long-distance data transmission over balanced twisted-pair lines.


Evaluating the Noise Performance of Coherent DSB‑SC Demodulators

Evaluating the Noise Performance of Coherent DSB‑SC Demodulators

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.


The Isolated Half-Bridge: An IGBT Gate Driver Module with Current Sense

The Isolated Half-Bridge: An IGBT Gate Driver Module with Current Sense

This project brief describes how to assemble an isolated half-bridge IGBT gate driver module built around the NCD57085DR2G. It features onboard current sensing and overcurrent protection.


Introduction to Clock and Data Recovery

Introduction to Clock and Data Recovery

Learn how PLLs enable communication in which a clock signal is not transmitted with the data. We’ll look specifically at return-to-zero (RZ) and non-return-to-zero (NRZ) data formats.


Foundations for PLL Nonlinear Analysis: Modeling the Phase Detector and VCO

Foundations for PLL Nonlinear Analysis: Modeling the Phase Detector and VCO

The phase-locked loop (PLL) is widely used in contemporary analog and digital communication systems. In this article, we develop a nonlinear model for the analog PLL by analyzing its key components.


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.


Why Class D Amplifiers Need Anti-Parallel Diodes

Why Class D Amplifiers Need Anti-Parallel Diodes

Learn how anti-parallel diodes protect Class D amplifiers from the effects of reactive loads and inductive kickback.