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Compact TTL system |
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All broadcast programs are transmitted from broadcasting stations located in the city to individual transmitters installed in high places such as on the tops of mountains, via Super High Frequency band radio signals called broadcast program relay circuits (Studio to Transmitter Link/Transmitter to Transmitter Link). NHK is developing a compact, low-cost transmission system, so that facilities can be constructed that will perform this transmission in cooperation with commercial broadcasters.
By employing intermediate frequency (IF) transmission and exploiting the technological developments mentioned below, this system should be able to reduce construction costs.
- Improved radiator efficiency through the use of a thermal conductor material device called a "heat pipe."
- Enhanced amplifier efficiency through the incorporation of a pre-distortion linearizer with temperature compensation in the transmitter.
The sharing of a single parabolic antenna by multiple beams, using an antenna multiplexer with little loss.
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Network synchronization adaptor for ISDB-T |
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To construct a broadcasting network using a single frequency network that can effectively utilize digital terrestrial broadcast-waves, the transmission timing of the broadcast-wave emissions at each transmitter must be synchronized. For this purpose, a system was fabricated to regulate the transmission timing at each transmitter.
To adjust the transmission timing, this system measures the signal transit-time to each transmitter to an accuracy of 1/10,000,000 second based on a synchronization time stamp signal inserted by the broadcasting station.
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