AdvancedA-002-009-008
In a frequency multiplier circuit, an inductance (L1) and a variable capacitor (C2) are connected in series between VCC+ and ground. The collector of a transistor is connected to a tap on L1. C2 in conjunction with L1 operate as a:
B
Answer
Circuit design and power supplies
Type
A
frequency divider
B
frequency multiplier
C
voltage divider
D
voltage doubler
Answer Notes
In this specific transistor circuit, the combination of the tapped inductor (L1) and the variable capacitor (C2) forms an LC resonant tank circuit. This network is placed at the output of a non-linear amplifier stage.
Because the non-linear amplifier produces an output rich in harmonics, the L1/C2 tank circuit is tuned to ring or resonate at one specific harmonic (a direct multiple of the fundamental input frequency).
By filtering out the fundamental frequency and all other unwanted harmonics, this LC combination selectively passes only the multiplied frequency, thereby operating as the frequency multiplier mechanism of the circuit.
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In a frequency multiplier circuit, an inductance (L1) and a variable capacitor (C2) are connected in series between VCC+ and ground. The collector of a transistor is connected to a tap on L1. A fixed capacitor (C3) is connected between the VCC+ side of L1 and ground. The purpose of C3 is to:
Next · A-002-009-009
In a circuit where the components are tuned to resonate at a higher frequency than applied, the circuit is most likely a: