Electromagnetic waves tend to become weak with distance. Signal frequency requires repeatition to reach long distances the use of phased lock loops in matching the frequencies form an important part of integrated circuits.
Typical communication systems constitute particular communication networks and transmission technologies. Data terminal equipments are the bridges that interconnect and allow the system to operate as a whole. The integration works, provided the procedures and controls are technically compatible meaning they speak and understand each other. Telecommunication is one such communication system, so too are data networks which carry voice, video and data streams.
Prediction by Gordon Moore
Digital technologies are accelerating at a pace never witnessed before. Integrated circuits which constitute the major component in an electronic circuit are becoming denser. One of the main building blocks in electronic circuit technology are PLL short for phased locked loops. PLL came into existence around the 1930s. Gordon Moore, one of the founders of Intel made a bold prediction in 1965 that the number of transistors in a single IC (integrated circuit) would double every two years. (His initial prediction stated that the doubling would happen every year). The prediction has stood firm for over fifty years even though IC technology has become more complex.
The exponential growth of technology has led to the rise of PLLs in ICs. Basic PLL consists of a phase detector, low pass filter, and aVCO – Voltagecontrolled oscillator. The following applications among others have extensive use of PLLs
• Frequency modulation as in FM networks and stereo decoders
• Frequency synthesis
• Motor controllers
Filtering noise from low-frequency applications was the earliest use of PLLs. Improvements in IC technology has led to thefeasibility of PLLs in high-frequency areas. In television transmission, PLLs are an important component in variable frequency filtering and regeneration of chopped signals.
PLLS and Bucs in Satellite Communication
Satellite signal transmission use PLL oscillators in the block upconverters (Buc).They convert lower frequency bands to ahigher frequency. Present day Bucs convert the L-band frequency signals to Ku band and C band frequencies. The L band refers to the electromagnetic spectrum of 1 to 2 GHz for communications.Working in tandem with a 10 MHz reference frequency the Bucscan transmit at the correct frequency. Bucsare used along with LNBs (The small device in front of dish antennae). LNBs are low noise block converters are on the receiving side of the transmission while the Bucs are on the transmitting side. VSAT systems utilize the Buc and LNB for bidirectional internet access from satellites. The Buc converts low digital frequencies into high radio frequencies allowing the wave to travel into space. Satellites and space crafts in earth orbits can access these high-frequency RF waves. Several frequencies form bands that carry data sets. Each transmission has unique identifiers allowing for aspecific instruction to and fro from the satellites to ground-based controllers.