Final answer:
To adjust the parallel resonance of a transistor's input impedance, the frequency should be altered. This is due to the relationship of resonant frequency with inductance and capacitance in an RLC circuit.
Step-by-step explanation:
To parallel resonance the same transistor input impedance, the parameter that should be adjusted is frequency. This is because in an RLC circuit, resonance occurs when the inductive reactance equals the capacitive reactance, and this state can be achieved by changing the frequency at which the circuit operates.
Example Calculations
To understand how the adjustments work, consider the following examples:
- For a resonant frequency of 1.00 GHz with an 8.00 nH inductor, you can use the formula for resonant frequency, f = 1 / (2π√(LC)), to calculate the needed capacitance.
- If you need a resonant frequency of 60.0 Hz using a 2.00 µF capacitor, you would adjust the inductance according to the same formula.
Understanding Resonance
In an RLC series circuit, if the capacitance increases by a factor of 4, the resonant frequency decreases, since it is inversely proportional to the square root of the capacitance. Likewise, increasing the self-inductance also lowers the resonant frequency for the same reason. However, changing the resistance does not affect the resonant frequency, it primarily affects the quality of the resonance or Q-factor.
SUMUP of the Final Answer
- Adjust frequency to parallel resonance transistor input impedance.
- Use resonance formula f = 1 / (2π√(LC)) for calculations.
- Increasing capacitance or inductance lowers resonant frequency; resistance affects Q-factor.