Term
| What is a Parametric amplifiers? |
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Definition
| A low-noise microwave amplifier that uses variable reactance to amplify microwave signals. |
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Term
| How does a Parametric amplifier operate? |
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Definition
| It uses a non-linear variable reactance to supply energy from an AC source to a load. Its operation is based on a capacitance that varies with time. |
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Term
| How can the gain of a Parametric amplifier be controlled. |
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Definition
| With a variable attenuator that changes the amount of pump power applied to the varactor. |
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Term
| How does a Parametric amplifier get its name? |
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Definition
| For the time-varying parameter, or value of capacitance associated with the operation. They are sometimes called Reactance Amplifiers because its operation is based on reactance. |
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Term
| What is the typical gain of a Parametric amplifier? |
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Definition
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Term
| What is the advantage of using reactance in a Parametric amplifier vice resistance in a conventional amplifier to provide amplification? |
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Definition
| Since reactance does not add thermal noise to a circuit, a Parametric amplifier produces much less noise then most conventional amplifiers. |
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Term
| What is the most elaborate feature of a Parametric amplifier? |
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Definition
| The mechanical tuning mechanism. |
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Term
| What is the electrical source called that provides the energy required to vary thge capacitance in a power amplifier? |
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Definition
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Term
| Where is the pump signal applied in a Parametric amplifier? |
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Definition
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Term
| Describe the Pump action in a Parametric amplifier? |
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Definition
| It is simple a sine-wave voltage applied to a varactor located in a resonant cavity. |
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Term
| What is an important consideration betwween the pump and the input signal to be amplified? |
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Definition
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Term
| What happens each time the pump decreases capacityance in a Parametric amplifier? |
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Definition
| Energy is transferred from the pump circuit to the input signal, achieving amplification. |
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Term
| What are the requirements for proper operation of a Parametric amplifier? |
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Definition
| The capacitance must be decreased when the input voltage is maximum and increased when the input voltage is minimum, so the pump signal frequency must be exactly double the frequency of the input signal. |
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Term
| What is the purpose of the ferrite circuylator in a Parametric amplifier? |
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Definition
| It improves stability by preventing reflection of the signal back into the amplifier which would cause oscillations. It also serves as an isolator to prevent source and load impedance changes from affecting the gain. |
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Term
| What is a Parametric amplifier called that is not phase-sensative? |
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Definition
| A Non-degenerative Parametric amplifier. |
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Term
| What is the difference between the pumps in a conventional Parametric amplifier and a Non-degenerative PArametric amplifier? |
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Definition
| The None-degenerative circuit uses a pump circuit with a frequency that is more then twice the input signal. |
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