Q of a circuit
What is Q
Generally speaking, a higher Q corresponds to a narrower bandwidth.
How is Q calculated?
Note that at resonance, a series circuit "appears" to be purely resistive (it behaves like a resistor). Below resonance it appears to be capacitive (it behaves like a capacitor), and above resonance it appears to be inductive (behaves like an inductor)
- X = capacitive or inductive reactance at resonance
- R = series resistance
- P = Power
- I = Current
This formula is for all series resonant circuits and also works for parallel resonant circuits in which a small resistor is in series with the inductor.
If there is a large resistor in parallel with both the inductor and the capacitor, the formula becomes:
For a given circuit element , the admittance is the reciprocal of the impedance.
Admittance is most useful in parallel AC circuit calculations where there are no series components. The equivalent admittance of a parallel circuit is the sum of the admittances of the components.
|Physical quantities||Current * Gain * Impedance * Power * Q of a circuit * Radiated Power Measurement * Reactance* Resistivity * Resonance * Voltage|
|Components||Baluns * Bipolar-Junction Transistors * Capacitors * Diodes * Inductors* Lasers * Microphones * Resistors * Transformers * Wire|
|Circuits||Attenuators * Digital Signal Processing (DSP) * Dummy load * Filters * LC filters * Power Supply Design * Rectifier Circuits|
|Design||Amplifier Design * Oscillator Design|
|Electromagnetic Waves||Relative power (Decibels) * Harmonics * Interference and BPL|