eefocus术语辞典
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中文解释:射频
英文缩写:RF
英文来历:Radio Frequency
无线电频率对通信很有使用价值的能量相干电磁辐射所在的频率。射频的划分如下：
甚低频: 频率低于30 kHz
低频: 30～300kHz
中频: 300～3000 kHz
高频: 3～30 MHz
甚高频: 30～300 MHz
特高频: 300～3000 MHz
超高频: 3～30 GHz
极高频: 30～300 GHz
频...
无线电频率对通信很有使用价值的能量相干电磁辐射所在的频率。射频的划分如下：
频率范围为30kHz至300GHz的射频电磁波。[2]
Radio frequency (RF) is a frequency or rate of oscillation within the range of about 3 kHz to 300 GHz. This range corresponds to frequency of alternating current electrical signals used to produce and detect radio waves. Since most of this range is beyond the vibration rate that most mechanical systems can respond to, RF usually refers to oscillations in electrical circuits or electromagnetic radiation.
Electrical currents that oscillate at RF have special properties not shared by direct current signals. One such property is the ease with which it can ionize air to create a conductive path through air. This property is exploited by 'high frequency' units used in electric arc welding. Another special property is an electromagnetic force that drives the RF current to the surface of conductors, known as the skin effect. Another property is the ability to appear to flow through paths that contain insulating material, like the dielectric insulator of a capacitor. The degree of effect of these properties depends on the frequency of the signals.
| 名字 | 符号 | 范围 | 波长 | 应用 |
|---|---|---|---|---|
| Extremely low frequency | ELF | a 3 to 30 Hz | k 10,000 km to 100,000 km | audible 20+ Hz, communication with submarines |
| Super low frequency | SLF | b 30 to 300 Hz | j 1,000 km to 10,000 km | audible, AC power grids (50 hertz and 60 hertz) |
| Ultra low frequency | ULF | c 300 Hz to 3 kHz | i 100 to 1000 km | audible, communication with mines |
| Very low frequency | VLF | d 3 to 30 kHz | h 10 to 100 km | audible range 20 Hz to 20 kHz (to be audible, energy must be simply converted to sound) |
| Low frequency | LF | e 30 to 300 kHz | g 1 to 10 km | international broadcasting, navigational beacons, lowFER |
| Medium frequency | MF | f 300 to 3000 kHz | f 100 m to 1 km | navigational beacons, AM broadcasting, maritime and aviation communication |
| High frequency | HF | g 3 to 30 MHz | e 10 to 100 m | shortwave, citizens' band radio |
| Very high frequency | VHF | h 30 to 300 MHz | d 1 to 10 m | FM broadcasting, broadcast television, aviation |
| Ultra high frequency | UHF | i 300 to 3000 MHz | c 10 to 100 cm | broadcast television, mobile telephones, wireless networking, microwave ovens |
| Super high frequency | SHF | j 3 to 30 GHz | b 1 to 10 cm | wireless networking, radar, satellite links. |
| Extremely high frequency | EHF | k 30 to 300 GHz | a 1 to 10 mm | microwave data links, radio astronomy, remote sensing, advanced weapons systems, advanced security scanning |