Wireless Communication Frequencies

Questions and Answers

Match the following microwave sources with their operating mode:

Vacuum tube based devices = density modulated mode Solid-state sources = current modulated mode Maser = laser-like mode Gyrotron = ballistic motion mode

Match the following frequency bands with their corresponding applications:

ISM band = Wireless LAN protocols U-NII frequencies = Licensed long-range Wireless Internet Access 5 GHz range = Metropolitan Area Networks 3.5–4.0 GHz range = Point-to-point links

Match the following wireless protocols with their operating frequencies:

Bluetooth = 2.4 GHz IEEE 802.11a = 5 GHz range WiMAX = 3.5–4.0 GHz range IEEE 802.16 = 2 to 11 GHz

Match the following microwave communication systems with their applications:

Point-to-point links = Long distance telephone calls Wireless LAN protocols = Local area networks Metropolitan Area Networks = Wide area mobile broadband Wireless Internet Access = Licensed long-range services Signup and view all the answers

Match the following microwave devices with their operating principles:

Magnetron = Ballistic motion of electrons Klystron = Density modulated mode Tunnel diodes = Current modulated mode Gyrotron = Stimulated emission of radiation Signup and view all the answers

Match the following microwave frequency bands with their corresponding applications:

2.4 GHz = Wireless LAN protocols 5 GHz range = Metropolitan Area Networks 3.5–4.0 GHz range = Licensed long-range Wireless Internet Access 110 GHz to 300 GHz = Millimeter wave band Signup and view all the answers

Match the following microwave sources with their characteristics:

Vacuum tube based devices = Operate on ballistic motion Solid-state sources = Use field-effect transistors Maser = Similar to a laser Gyrotron = Work in the current modulated mode Signup and view all the answers

Match the following wireless protocols with their corresponding standards:

WiMAX = IEEE 802.16 Bluetooth = IEEE 802.11 IEEE 802.11a = Wireless LAN protocols IEEE 802.16 = Metropolitan Area Networks Signup and view all the answers

Match the following microwave applications with their characteristics:

Point-to-point links = Up to 70 km away Wireless LAN protocols = Use ISM band Metropolitan Area Networks = Use WiMAX Licensed long-range Wireless Internet Access = Up to 25 km away Signup and view all the answers

Match the following microwave frequency bands with their corresponding applications:

2.4 GHz = Wireless LAN protocols 5 GHz range = Metropolitan Area Networks 3.5–4.0 GHz range = Licensed long-range Wireless Internet Access ISM band = Bluetooth Signup and view all the answers

Study Notes

Microwave Frequencies

Commercial implementations operate in 2.3 GHz, 2.5 GHz, 3.5 GHz, and 5.8 GHz ranges.
MBWA protocols operate between 1.6 GHz and 2.3 GHz for mobility and in-building penetration.

Microwave Applications

Cable TV and internet access use lower microwave frequencies.
Mobile phone networks, like GSM, use lower microwave frequencies.
Microwave radio is used in broadcasting and telecommunication transmissions due to its short wavelength and high spectral efficiency.

Radar and Remote Sensing

Radar uses microwave radiation to detect range, speed, and characteristics of remote objects.
Radar is used in air traffic control, navigation of ships, and speed limit enforcement.

GNSS, including GPS, broadcast navigational signals between 1.2 GHz and 1.6 GHz.

Power and Energy

Microwave ovens use non-ionizing radiation at 2.45 GHz to heat food.
Microwave heating is used in industrial processes for drying and curing products.
Microwaves can be used to transmit power over long distances.

Microwave Frequency Bands

The microwave spectrum ranges from approximately 1 GHz to 1000 GHz in frequency.
The IEEE defines the millimeter wave band as 110 GHz to 300 GHz.

Microwave Sources

Vacuum tube-based devices operate on ballistic motion of electrons in a vacuum.
Solid-state sources include field-effect transistors, tunnel diodes, and Gunn diodes.

Communication

Microwave point-to-point links were used for long-distance telephone calls before fiber optic transmission.
Frequency division multiplex was used to send up to 5,400 telephone channels on each microwave radio channel.
Wireless LAN protocols, such as Bluetooth and IEEE 802.11, use microwaves in the 2.4 GHz ISM band.
Licensed long-range Wireless Internet Access services operate in the 3.5-4.0 GHz range.