- •Учреждение образования «высший государственный колледж связи» «чтение и перевод технических текстов по специальности ткс»
- •Часть I
- •Введение
- •Unit 1 (17) Antennas
- •17.1 Types of antennas
- •17.1.1 Antennas used in communications
- •17.2 Basic properties
- •17.3 Generic antenna types
- •17.3.1 Radiation from apertures
- •1 Learn the words & word combinations:
- •2 Read & translate the text (orally) 17.1 – 17.3.2:
- •3 Find Russian equivalents:
- •4 Find English equivalents:
- •5 Answer the questions:
- •17.3.2 Radiation from small antennas
- •17.3.3 Radiation from arrays
- •17.4 Specific antenna types
- •17.4.1 Prime focus symmetric reflector antennas
- •17.4.1.1 Parabolic reflectors
- •17.4.1.2 Aperture fields and radiation patterns
- •17.4.1.3 Gain of reflector antennas
- •1Learn the words & word combinations:
- •2 Read & translate the text (orally) 17.3.2 – 17.4.1:
- •3 Find Russian equivalents:
- •4 Find English equivalents:
- •5 Answer the questions:
- •17.4.2 Dual symmetric reflector antennas
- •17.4.3 Offset reflectors
- •17.4.4 Horn feeds for reflector antennas
- •17.4.4.1 Rectangular or square horns
- •17.4.4.2 Small conical horns
- •17.4.4.3 Multi-mode conical horns
- •17.4.4.4 Conical corrugated horns
- •17.4.4.5 Array feeds
- •1 Learn the words & word combinations:
- •2 Read & translate the text (orally) 17.4.2 – 17.4.4:
- •17.5.2 Earth station antennas
- •1 Learn the words & word combinations:
- •2 Read & translate the text (orally) 17.5.1 – 17.5.2:
- •17.5.3.2 Spot beams
- •17.5.3.3 Multiple beams
- •17.5.3.4 Shaped beams
- •17.5.4 Vhf and uhf communications
- •17.5.5 Hf communications
- •1 Write out the words and word combinations which are still unknown to you and learn them. Unit 2 (20) Frequency division multiplexing
- •20.1 Fdm principles
- •20.2 History
- •20.3 Fdm hierarchy
- •20.3.1 General considerations
- •20.3.2 Channel bandwidth
- •20.3.3 Group and supergroup
- •20.3.4 Higher order translation
- •2 Read & translate the text (orally) 20.1 – 20.3.4:
- •3 Find Russian equivalents:
- •4Find English equivalents:
- •5 Answer the questions:
- •20.4 Frequency translation
- •20.4.1 Ring bridge modulator/demodulator design considerations
- •20.4.1.1 Carrier compression.
- •20.4.1.2 Carrier and signal suppression
- •20.5 Carriers
- •20.5.1 Carrier frequency accuracy
- •20.5.2 Carrier purity
- •20.6.2 Line equipment pilots
- •20.6.2.1 Regulation pilots
- •20.6.2.2 Frequency comparison pilots
- •1 Learn the words & word combinations:
- •2 Read & translate the text (orally) 20.4 – 20.6
- •3 Find Russian equivalents:
- •4. Find English equivalents:
- •5. Answer the questions:
- •20.7 Noise contributions
- •20.7.1 Definitions
- •20.7.2 Psophometric weighting
- •20.7.3 Thermal noise
- •20.7.4 Noise due to unlinearity
- •20.7.4.1 Single channel load
- •20.7.4.2 Multichannel load
- •20.7.4.3 Unlinearily characterisation
- •20.7.4.4 Determination ofunlinearity noise from a multichannel load
- •20.7.4.5 Approximate value for the weighted intermodulation noise contribution
- •20.7.4.6 Weighted noise power in pWOp
- •20.7.4.7 Determination of unlinearity noise using spectral densities
- •1 Learn the words & word combinations:
- •2 Read & translation the text (orally) 20.7:
- •20.9 Overload
- •20.9.1 Overload measurement.
- •20.9.1.1 Harmonic/intermodulation products
- •20.9.1.2 Gain change
- •20.10 Hypothetical reference system
- •20.10.1 Noise contributions
- •20.10.2 Line sections
- •1 Learn the words & word combinations:
- •2 Read & translate the text (orally) 20.8 -20.10:
- •20.11.2 Multichannel load increase
- •20.11.3 Compandor noise advantage
- •20.11.4 Attack and decay time
- •20.11.5 Usage of companders
- •20.12 Through connections
- •20.12.1 Through connection filter
- •20.13 Transmultiplexers
- •20.13.1 Synchronisation
- •20.13.2 Pcm alarms
- •20.14 Repeatered cable line equipment
- •20.14.1 Pre-Emphasis
- •20.14.2 Thermal noise
- •20.14.3 Regulation
- •20.14.3.1 Regulation range
- •20.14.4 Power feeding
- •«Чтение и перевод технических текстов по специальности ткс»
- •Часть I
20.14.4 Power feeding
A constant current is normally used to serially feed the repeatered cable. A constant current ensures a consistent power delivered to each repeater even though the cable resistance is continuously shifting with the cable temperature.
The power is normally fed from both ends of the section with a turn round break in the centre. This break is important as the induction of unwanted currents from services (rail traction, grid systems etc.) that may run parallel with the transmission is proportional to the square of the effective coupled path (CCITT, 1985, KIT).
Under traction or grid faults where very large currents may flow for a short period in the service cable, excessive voltages may be coupled into the transmission cable and can damage the repeaters and cause an insulation breakdown within the cable.
Even under normal conditions a long coupled path with a.c. traction or similar installations can cause the transmission power feed current to be modulated with the traction frequency, or its harmonics. This will create unwanted modulation products within the required multichannel traffic load.
Read the text; mind the meaning of the following words and word combinations:
|
Transmultiplexer |
Преобразователь вида уплотнения (сигналов, каналов) |
|
Bare frequency |
Опорная частота |
|
Bareband |
Полоса частот модулирующих сигналов, групповой спектр передаваемых сигналов |
|
Digital switch |
Цифровой дискретный переключатель |
|
To interface |
Сопрягать, согласовать |
|
Block diagram |
Блок-схема, гистограмма |
|
Frame slip |
Проскальзывание циклового импульса |
|
TSO (time sharing option) |
Операционная система ТСО |
|
A supervisory overlay system |
Система накладного диспетчерского управления |
|
repeater |
Ретранслятор |
|
Preemphasis |
Предискажение |
|
Noise figure |
Коэффициент шума |
|
Noise matching |
Согласование по минимуму шумов |
|
Pilot frequency |
Частота пилот-сигнала |
|
Frequency response |
Амплитудно-частотная характеристика (АХЧ) |
|
Buried cable |
Подземный кабель |
|
Service cable |
Абонентский кабель |
|
Traction |
Тяга, тяговое усилие |
Translate the text 20.11 – 20.14.4
Translate in written form point 20.13 “Transmultiplexers”
План _____/_____ Поз.____
Ращинская Ирина Николаевна
«Чтение и перевод технических текстов по специальности ткс»
Методическое пособие
по дисциплине «АНГЛИЙСКИЙ ЯЗЫК»
Часть I
для студентов уровня ВО, 3 курс, 5 семестр
специальности 1-45 01 03 – Сети телекоммуникаций
Редактор Н. В. Вердыш
Подписано к печати ____________
Формат 60х84/16
Усл.печ.л.___ Уч.изд.л. ___
Тираж____экз. Заказ _____
Учреждение образования
«Высший государственный колледж связи»
220114, г. Минск, Староборисовский тракт, 8, к.2