Advantages of CFA, disadvantages of CFA, Crossed Field Amplifier
This page covers advantages and disadvantages of CFA (Crossed Field Amplifier). It mentions CFA advantages or benefits and CFA disadvantages or drawbacks. It provides links on various topics on CFAs (Crossed Field Amplifiers).
What is CFA?
The Crossed Field Amplifier (CFA) can be used as broadband amplifier and as oscillator. It solves the low efficiency problem of TWT without comprising on the bandwidth. The efficiencies of upto 80% can be achieved using CFA device.
Its working principle is similar to magnetron and provide large amount of power. There are two types of CFA based on its structure viz. forward wave CFA amd backward wave CFA. Forward wave CFA uses helix as slow wave structure while backward wave CFA uses bar line as slow wave structure. In CFA, velocity modulation occurs in region of crossed electric fields and magnetic fields.
The figure-1 depicts diagram of crossed field amplifier (CFA). As shown it consists of electron gun, negative electrode (called sole), collector plate and ports for input (where weak signal to be amplified is fed) and output (where amplified output is derived) . Refer CFA basics >>.
Benefits or advantages of CFA | Crossed Field Amplifier
Following are the benefits or advantages of CFA (Crossed Field Amplifier):
➨As mentioned above, higher efficiencies upto 80% can be achieved in CFA unlike TWT.
➨Higher efficiencies are achieved in CFA without compromising on bandwidth (BW). Wide bandwidth can be achieved using CFA device. BW of 25% or less of center frequency and as high as 50% of center frequency can be achieved in injected beam CFA.
➨It has higher power handling capability. Peak power of 4 MW at 2 GHz and 1 MW at 10 GHz can be achieved using pulsed CFA device.
➨It has slow wave structure similar to TWT.
Drawbacks or disadvantages of CFA | Crossed Field Amplifier
Following are the disadvantages of CFA (Crossed Field Amplifier):
➨It is a low gain device. It is 10 to 15 dB lower compare to klystron/TWT.
➨It has high noise output.
➨It has low average power capability.