OPMW UNIT 5

The production of power at higher frequencies is much simpler than production of power at low frequencies.

• True

• False

• none of the above

Microwave tubes are power sources themselves at higher frequencies and can be used independently without any other devices.

• True

• False

• None of the Above

Microwave tubes are grouped into two categories depending on the type of:

• Power gain achieved
  

• Amplification method

• Electron beam field interaction

• Construction methods

The klystron tube used in a klystron amplifier is a _________ type beam amplifier.

• Linear Beam

• Crossed field

• Parallel field

• None of the mentioned

________ is a single cavity klystron tube that operates as on oscillator by using a reflector electrode after the cavity.

• Backward wave Oscillator

• Reflex klystron

• Travelling wave tube

• Magnetrons

A major disadvantage of klystron amplifier is:

• Low power gain

• Low Bandwidth

• High Source power

• Design complexity

Klystron amplifiers have high noise output as compared to crossed field amplifiers.

• True

• False

• None of the above

Magnetrons are microwave devices that offer very high efficiencies of about 80%.

• False

• True

Reflex klystron is a

•   Low Power Generator

• High Power Generator

• Low Gain Amplifier

• Not an Oscillator

The modes in a reflex klystron

• give the same frequency but different transit time

• result from excessive transit time across the resonator gap

• are caused by spurious frequency modulation

• are just for theoretical considerations