A duplexer is a duplexer that is a three-port frequency-related device that is used for transmission or reception purposes.
It can use different frequency bands, multiplex and demultiplex both ports and place them on one port on a coaxial cable. Or the duplexer can route signals based on frequency, which have sufficient bandwidth and can effectively transmit them to the air. The duplexer basically combines the signal to a download or sometimes links its signal to the radio transmitter.
The passive device can also separate the two signals instead of being located on the same receive path as audio and data in a Digital Subscriber Line [DSL] telephone system, or combining the two signals into a single output on the same transmit path. It can also force a constant impedance to occupy a single broadcast frequency, or enable a transmitter used by a broadcast station to operate and transmit multiple frequencies simultaneously with one RF antenna.
In addition, the antenna duplexer is an electronic component that can also be used to transmit and receive simultaneously using the same antenna - or it can use a single antenna while preventing the output of the other antenna. They allow signals from the antenna and satellite TV to share the same feed. More importantly, it can separate signals based on the frequency used.
In terms of disadvantages, the duplexer is not suitable for signals with overlapping frequency ranges. If the transmitter's frequency is too close, the duplexer cannot be successfully combined.
Typically, duplexers are used for high frequency satellite signals and low frequency CATV [cable television] / OTA [air] antenna signals. They can also be used as part of the front-end module of a mobile telecommunications system.
Duplexers are essential when trying to overcome the problem of prohibiting the construction of new towers in certain areas. It is now difficult to obtain a permit to build a new launch tower in many places, as there are laws that stipulate that people cannot build towers. Many of these restrictions are driven by the Federal Aviation Administration [FAA] and the Federal Communications Commission [FCC] rules regarding tower installation restrictions and local zoning regulations.
Although there are exceptions for companies that are classified as "utilities" even in areas that are explicitly prohibited, it is almost impossible to build a new tower.
Only use existing towers as much as possible to overcome this problem. An agreement must be reached with the owner of the established transfer site. from
This is where the duplexer comes into play - allowing two bands to be transmitted together without an interview.
Duplex is a suitable solution for medium wave radio stations, allowing multiple transmitters [such as UHF / VHF] from a single prefabricated tower to be used for broadcast television reception.
Duplex AM [amplitude modulation] transmitters are said to be easier than duplex FM [frequency modulation] transmitters because not all radiators are suitable for that type of transmission. In fact, the antenna must use broadband technology to transmit a wide range of FM frequencies.
Distance is also a factor affecting FM transmission, not AM transmission.
Since FM duplex requires special attention, if the antenna has not been built for this type of transmission, the cost can be a problem. Other factors that need to be evaluated include:
- Is the tower antenna non-directional or directional?
- What is the antenna efficiency?
- Does the tow have the desired direction?
The example of a tower duplexer [TMD] is plentiful.
An example of a TMD is the Sutro Tower in San Francisco, a 977-foot steel tower that is used by 11 television stations, 4 FM radio stations, as well as satellite companies, cable providers, and wireless communication services. More iconic is the Empire State Building in New York, which has a very busy duplexer, which appeared in March 1952, in which ABC and CBS FM stations operate using ordinary antennas.
These signals are duplexed into a set of dipoles on subsequent stations. The antenna is near the bottom of the tower.
Obviously, although buildings are banned from new towers, duplexers are critical in allowing new transmissions. Thanks to these devices, even with the tower building block, the station is able to prevent intermodulation and maintain the voltage component of the standing wave [VSWR] at the minimum amount of each input transmitter and frequency.
Therefore, new transfers can still be allowed.
Despite this, the duplexer seems to satisfy the wishes of the residents, who no longer need to build more towers and can meet the needs of businesses that need to have transmit/receive antennas for telecommunications. With such equipment and purposes, the tower can be used to provide communication system capabilities to locals, and the company can have a transmission medium for conducting business.
Orignal From: How the antenna duplexer broadcasts multiple times on one transmitter
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