Explore Signals and Systems Through Interactive GeoGebra Applications
GeoGebra is a free, powerful interactive mathematics software that allows you to visualize and explore mathematical concepts dynamically. For signals and systems, it provides an intuitive way to understand complex transformations, system responses, and frequency-domain analysis.
Use GeoGebra directly in your web browser without installation. Works on any device with internet connection.
Open CalculatorDownload and install GeoGebra Classic for full offline functionality and better performance.
Download AppAccess GeoGebra on iOS and Android devices for learning on the go.
iOS App | Android AppExplore: Amplitude, frequency, phase, and DC offset
Visualize how changing parameters affects the shape and characteristics of sine and cosine waves. Perfect for understanding periodic signals and their properties.
Amplitude
Adjust signal height
Frequency
Change oscillation rate
Phase
Shift signal in time
DC Offset
Vertical displacement
Interactive Features: Sliders for A, Ο, Ο, and DC components | Real-time equation display | Multiple signal comparison
π Launch VisualizationExplore: Discontinuous signals and their properties
Understand the fundamental building blocks of signal processing: unit step function u(t) and impulse function Ξ΄(t). See how these signals behave and how they're used to construct more complex signals.
Interactive Features: Time-shifted versions | Signal composition | Pulse width variation
π Launch VisualizationExplore: Growing and decaying exponentials
Visualize exponential functions e^(at) with different time constants. Essential for understanding system transient responses and RC/RL circuits.
Decay
a < 0
Growth
a > 0
Time Constant
Ο = 1/|a|
Explore: x(t - tβ) - Delaying and advancing signals
Understand how time shifts affect signal position. Positive shifts delay the signal (shift right), negative shifts advance it (shift left). Critical for understanding system delay and causality.
Key Concepts:
Explore: x(at) - Compression and expansion
See how time scaling changes signal speed. Time compression (a > 1) makes signals faster, time expansion (0 < a < 1) makes them slower.
Compression
x(2t) - Twice as fast
Expansion
x(t/2) - Half as fast
Reversal
x(-t) - Flip signal
Explore: xβ(t) + xβ(t) and xβ(t) Γ xβ(t)
Visualize how signals combine through addition and multiplication. Essential for understanding modulation, mixing, and superposition.
Interactive Features: Select different signal types | Adjust individual signal parameters | See the resulting combined signal
π Launch VisualizationExplore: x(t) = x_e(t) + x_o(t)
Any signal can be decomposed into even and odd components. This visualization shows the original signal alongside its even part [x(t) + x(-t)]/2 and odd part [x(t) - x(-t)]/2.
Key Properties:
Explore: y(t) = x(t) * h(t) - The convolution integral
See convolution in action! This interactive tool shows how the output signal is formed by sliding, flipping, multiplying, and integrating. Watch the h(Ο) function flip to h(t-Ο) and slide across x(Ο).
Flip
h(Ο) β h(-Ο)
Shift
h(-Ο) β h(t-Ο)
Multiply
x(Ο)Β·h(t-Ο)
Integrate
β« x(Ο)h(t-Ο)dΟ
Interactive Features: Step-by-step animation | Adjustable time slider | Product visualization | Area under curve display
π Launch VisualizationExplore: dy/dt + ay = bx(t)
Visualize first-order system behavior including natural response, forced response, and total response. Adjust time constant Ο = 1/a and see how it affects settling time.
Natural
Zero-input response
Forced
Zero-state response
Total
Complete solution
Explore: dΒ²y/dtΒ² + 2ΞΆΟ_n(dy/dt) + Ο_nΒ²y = Ο_nΒ²x(t)
Understand how damping ratio ΞΆ affects system behavior. See underdamped, critically damped, and overdamped responses side by side.
Underdamped
ΞΆ < 1 (oscillatory)
Critical
ΞΆ = 1 (fastest)
Overdamped
ΞΆ > 1 (slow)
Key Parameters: Natural frequency Ο_n, damping ratio ΞΆ, overshoot, settling time
π Launch VisualizationExplore: First-order RC low-pass filter
Interactive RC circuit showing both time-domain (step response) and frequency-domain (Bode plot) behavior. Adjust R and C values to see how cutoff frequency changes.
Displays: Time constant Ο = RC | Cutoff frequency f_c = 1/(2ΟRC) | -3dB point | Phase response
π Launch VisualizationExplore: Building periodic signals from harmonics
Watch as a complex periodic waveform is constructed by adding harmonics one by one. Start with the fundamental frequency and add harmonics to see the signal take shape. Demonstrates Gibbs phenomenon at discontinuities.
Fundamental
Base frequency
Add Harmonics
Integer multiples
Spectrum
Frequency content
Waveforms Available: Square wave, Sawtooth, Triangle, Pulse train
π Launch VisualizationExplore: Magnitude and phase spectra
See both time-domain and frequency-domain representations simultaneously. Adjust signal parameters and watch how the spectrum changes in real-time.
Interactive Features: Magnitude spectrum |X(f)| | Phase spectrum β X(f) | Time-frequency relationship | Bandwidth visualization
π Launch VisualizationExplore: Duality, time-shift, frequency-shift, scaling
Interactive demonstration of key Fourier transform properties. See how operations in the time domain affect the frequency domain and vice versa.
Time Shift
Phase change
Modulation
Frequency shift
Scaling
Inverse relationship
Convolution
Multiplication in FD
Explore: e^(jΟt) representation and rotating phasors
Visualize complex exponentials as rotating vectors in the complex plane. Understand how real sinusoids relate to complex exponentials through Euler's formula.
Key Concepts: e^(jΟt) = cos(Οt) + jΒ·sin(Οt) | Phasor rotation | Real and imaginary components | 3D visualization option
π Launch VisualizationExplore: AM modulation and demodulation
See how amplitude modulation works in communications. Adjust carrier frequency, message frequency, and modulation index to understand the modulation process.
Message
Information signal
Carrier
High frequency
Modulated
Combined signal
Key Parameter: Modulation index ΞΌ determines envelope shape and bandwidth
π Launch VisualizationExplore: Low-pass, high-pass, and band-pass filters
Interactive filter design tool showing frequency response and filtered output. Apply different filters to input signals and observe the results.
Low-Pass
Keep low frequencies
High-Pass
Keep high frequencies
Band-Pass
Keep frequency band
Explore: Nyquist theorem and aliasing effects
Understand the sampling theorem by seeing what happens when you sample below, at, and above the Nyquist rate. Watch aliasing occur when sampling rate is too low.
Interactive Features: Adjustable sampling rate | Original vs sampled signal | Reconstructed signal | Frequency domain view | Aliasing demonstration
π Launch VisualizationExplore: Frequency response of LTI systems
Design transfer functions and see their Bode plots (magnitude and phase). Adjust poles and zeros and watch how they affect the frequency response.
Features: Pole-zero placement | Gain adjustment | Magnitude response (dB) | Phase response (degrees) | Cutoff frequency marking
π Launch VisualizationBefore opening a visualization, identify what concept you want to understand. Read the related textbook section first, then use the visualization to reinforce the concept.
Don't be afraid to play with sliders and parameters. Sometimes "breaking" things helps you understand the limits and constraints of a concept.
As you interact, ask yourself: "What happens if...?" "Why does it behave this way?" "Can I predict what will happen before I adjust the slider?"
Document interesting observations and patterns you discover. These insights often become exam questions or useful problem-solving techniques.
Use multiple visualizations together. For example, explore a signal transformation, then see how it affects the system response through convolution.
Spend at least 10-15 minutes with each visualization. Deep understanding comes from thorough exploration, not quick glances.
| Task | Recommended Visualization |
|---|---|
| Understanding signal properties | Basic Signal Visualizations |
| Mastering time transformations | Time Shifting & Scaling Tools |
| Grasping convolution concept | Convolution Visualization |
| Understanding frequency content | Fourier Series & Transform |
| System response behavior | First/Second-Order Systems |
| Filter design and analysis | Ideal Filters & Bode Plots |
Complement visualizations with code implementation. Practice the same concepts programmatically.
Open Tutorial βAlternative coding approach with NumPy, SciPy, and Matplotlib for signal processing.
Open Tutorial βAccess lecture slides, notes, and assignments on Blackboard.
Open Blackboard βContact Dr. Al Bataineh during office hours (Monday/Wednesday 11:00 AM - 12:00 PM)
Email: mffbataineh@uaeu.ac.ae | Office: F1-1175