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…
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.
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.
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 project article, we’ll create a programmable device that alerts users to changes in ambient light levels. Along…
In this project article, we’ll create a programmable device that alerts users to changes in ambient light levels. Along the way, we’ll learn about astable multivibrators and the Darlington pair.
In this article, we examine the oscillation behavior of an LED blinker circuit in QSPICE and learn how to control its…
In this article, we examine the oscillation behavior of an LED blinker circuit in QSPICE and learn how to control its ON-time and pulse repetition frequency.
The common-drain amplifier is a single-stage configuration that uses the gate as its input and the source as its output.…
The common-drain amplifier is a single-stage configuration that uses the gate as its input and the source as its output. Learn about its small-signal characteristics in this article.
In this project, we mix the old and the new by integrating present-day BLE technology with a vintage Science Fair computer kit.
In this project, we mix the old and the new by integrating present-day BLE technology with a vintage Science Fair computer kit.
To avoid distortion and slow transitions in an operational amplifier's output signal, it's important to understand slew…
To avoid distortion and slow transitions in an operational amplifier's output signal, it's important to understand slew rate. In this article, we examine its causes and effects.
In this article, we conclude our discussion of VNAs by walking through the steps of a SOLT calibration and examining the…
In this article, we conclude our discussion of VNAs by walking through the steps of a SOLT calibration and examining the potential non-idealities of its reference standards.
This article explains how to estimate the dynamic range a vector network analyzer (VNA) needs for a given measurement,…
This article explains how to estimate the dynamic range a vector network analyzer (VNA) needs for a given measurement, then discusses four techniques for boosting the dynamic range to the required level.
In this article, we investigate two metrics used to characterize the performance of RF test and measurement systems.
In this article, we investigate two metrics used to characterize the performance of RF test and measurement systems.
In this article, we explore how the signal source and receivers of a VNA enable its function.
In this article, we explore how the signal source and receivers of a VNA enable its function.
Directional couplers are valuable tools for testing RF systems. However, the finite directivity of these devices can…
Directional couplers are valuable tools for testing RF systems. However, the finite directivity of these devices can cause measurement uncertainty. Learn more in this article.
As part of a vector network analyzer (VNA), a directional coupler enables us to characterize a device’s performance by…
As part of a vector network analyzer (VNA), a directional coupler enables us to characterize a device’s performance by its S-parameters. Read this article to learn more about this important piece of equipment.
A PIR sensor detects objects to allow a Raspberry Pi Pico running MicroPython code to adjust the frequency of a Science…
A PIR sensor detects objects to allow a Raspberry Pi Pico running MicroPython code to adjust the frequency of a Science Fair electronic oscillator circuit with audio output.
This article, the second in a series on hysteresis, explains two types of hysteresis found in engineered systems.
This article, the second in a series on hysteresis, explains two types of hysteresis found in engineered systems.
This article explains how to use a histogram test with a sinusoidal input to determine analog-to-digital converter (ADC)…
This article explains how to use a histogram test with a sinusoidal input to determine analog-to-digital converter (ADC) parameters, along with the advantages of doing so.