My speciality. Овчинникова Т.Е - 43 стр.

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     2.14.8 Define the tense and voice of the predicate in the first sentence
(paragraph 3). Find adjectives in the comparative degree and give two other
degrees

      2.14.9 Read a question for each paragraph, find answers in the text

1.When is electronic movement of the radar beam essential? 2. In what radars has
electronic scan beam successfully used? 3. What scanning is being applied for these
systems 4. What constitutes a digital phase shifter?


                                ELECTRONIC SCAN

1. Electronic movement of the radar beam is essential when the radar must operate in
many modes simultaneously Another principal reason for going to electronic scan is
the high failure rate of mechanically scanned antennas.
2. For some time now, electronic scan has been used sue successfully in large ground
radars like the Nike MAR and aboard large ships, as in the Hughes radars on the
carrier Enterprise The emphasis therefore has switched to a search for simpler lighter
scanning systems for use on small ships, in air craft, and on the battlefield, where the
radar must be transported by motor vehicle or even by men on foot.
3. Both phase-phase scanning and phase-frequency scanning are being applied for
these systems. For either type о scan, better ferrite phase shifters are needed that have
greater power handling ability, lower RF losses, and better temperature stability,
require less drive power, and cost less since even a small phase-phase array uses
several thousand phase shifters, the cost factor is anything but negligible
4. A very important development has been the appearance of digital latching phase
shifters. These devices use ferrite elements in waveguides that can be switched from
one saturation state to the other by a video pulse and remain in the new state between
pulses. The result is a discrete shift in the phase of microwave energy passing through
the guide. A set of such elements on a single guide constitutes a digital phase shifter,
which can be controlled directly by digital circuits, so that there is a natural interface
with the digital computer controlling the radar. The drive power required to change
the phase shift setting is much less than that required by analogue phase shifters.

      2.14.10 Translate the word-combinations

radar beam, electronic scan, high failure rate, ground radar, multifunctioning array
radar, phase-phase scanning, phase-frequency scanning, ferrite phase shifters, power han-
dling ability, drive power, digital computer, digital latching phase shifters,
waveguide, discrete shift, digital phase shifter, digital circuits, analogue phase shifter.