Vocabulary

transducer - преобразователь датчик vice-versa - наоборот intercept - перехватить, прерывать, выключать, останавливать, помешать source - источник feeder - фидер adjust - регулировать impedance - сопротивление gain - коэффициент усиления radiation pattern - диаграмма излучения by means of - посредством

Answer

1.What is antenna? 2. What does the form and size of the aerial depend on? 3. What type of antenna is used for satellite communication? 4. What are the parameters affecting the antenna performance? 5. What is the function of feeder? 6. What types of antennas are used for vihicles?

Antenna (radio)

Fill in the gaps using the following words and expressions

free space spacecraft communication transmission loss voltage electrical currents conductive materials elements frequencies radio equipment waves arrangement electromagnetic waves

An antenna (or aerial) is a transducer designed to transmit or receive ….. In other words, antennas convert electromagnetic waves into …...and vice versa. They are used with waves in the radio part of the electromagnetic spectrum, that is, radio waves, and are a necessary part of all …... Antennas are used in systems such as radio and television broadcasting, point-to-point radio communication, cell phones, radar, and ….. Antennas are most commonly employed in air or outer space, but can also be operated under water or even through soil and rock at certain …. for short distances.

Physically, an antenna is an ….. of one or more conductors, usually called elements. In transmission, an alternating current is created in the elements by applying a …..at the antenna terminals, causing the elements to radiate an electromagnetic field. In reception, the inverse occurs: an electromagnetic field from another source induces an alternating current in the ….. and a corresponding voltage at the antenna's terminals. Some receiving antennas (such as parabolic and horn types) incorporate shaped reflective surfaces to collect EM waves from …….and direct or focus them onto the actual conductive elements.

In air radio signals travel very quickly and with a very low…... The signals are absorbed when moving through more……, such as concrete walls or rock. When encountering an interface, the ……are partially reflected and partially transmitted through.

Translate

Преобразовывать, датчик, индуцировать, электродвижущая сила, радиовещание, беспроводная антенна, проводящие элементы, открытый космос, потеря