Frequency Bandwidth Calculator
Calculate frequency bandwidth, cutoff frequencies, and quality factor for RF systems
Calculate Frequency Bandwidth
Resonance frequency or geometric mean of cutoff frequencies
Measure of how underdamped the resonator is (unitless)
Bandwidth Analysis Results
Formulas used: f_BW = f₀/Q = f_u - f_l, f₀ = √(f_u × f_l)
3dB point: Power is reduced to 50% (-3dB) at cutoff frequencies
Applications: Filter design, antenna systems, RF circuits, signal processing
Bandwidth Analysis
Example Calculation
FM Radio Station
Center frequency: 93.7 MHz
Quality factor: 500
Application: Radio broadcasting
Calculation
f_BW = f₀/Q = 93.7/500 = 0.1874 MHz
f_l = 93.6 MHz
f_u = 93.8 MHz
Bandwidth = 0.187 MHz
Frequency Band Applications
Key Concepts
3dB bandwidth: frequency range where power ≥ 50%
Higher Q = narrower bandwidth = more selective
Center frequency is geometric mean of cutoffs
Quality factor measures resonator sharpness
Understanding Frequency Bandwidth
What is Frequency Bandwidth?
Frequency bandwidth is the difference between the upper and lower frequencies in a continuous band that a system can process or transmit. It defines the range of frequencies where the system maintains effective signal transmission or reception.
3dB Bandwidth
- •Also called half-power bandwidth
- •Power drops to 50% at cutoff frequencies
- •-3dB corresponds to √2 voltage reduction
- •Standard reference for filter design
Key Formulas
fBW = f₀ / Q
fBW = fu - fl
f₀ = √(fu × fl)
- fBW: Frequency bandwidth
- f₀: Center frequency (resonance)
- Q: Quality factor (dimensionless)
- fu, fl: Upper and lower cutoff frequencies
Quality Factor: Q = f₀/fBW measures how "sharp" the resonance is
Applications and Use Cases
Communication Systems
- • Radio and TV broadcasting
- • Cellular networks (3G, 4G, 5G)
- • WiFi and wireless LANs
- • Satellite communications
- • Bluetooth and IoT devices
- • Amateur radio operations
Electronic Systems
- • Filter design (low-pass, high-pass, band-pass)
- • Amplifier frequency response
- • Oscillator and resonator circuits
- • Antenna design and matching
- • Signal processing systems
- • Medical imaging equipment
Design Considerations
Narrow Bandwidth (High Q):
- Better selectivity and rejection
- Lower noise bandwidth
- Slower response time
- More sensitive to temperature/component drift
Wide Bandwidth (Low Q):
- Faster response and settling time
- Better stability with variations
- Higher data rates possible
- Less selective, more noise