Telescopes

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Amplifiers don’t work at very high frequencies, so must change to a lower frequency before amplifying

Want all of the electronics that change the signal to forms we can record and analyze to only have to be designed for one frequency (called baseband frequency).

If the signal must be transmitted a long distance, there will be less loss if the frequency is first shifted to a lower frequency

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Receivers

The design of the receiver is effected greatly by whether the radiation observed is radio, millimeter, or submillimeter.

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Receivers

The size of the electronics gets smaller as the wavelength gets shorter (higher frequencies)

So devices associated with radio telescope receivers

(long wavelength) are larger than the devices associated with millimeter and submillimeter receivers (shorter wavelengths).

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Radio receivers

Radio

100MHz - 100GHz

3m-3mm

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Radio receivers

Arecibo Observatory

receivers

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Arecibo radio telescope

Receivers are inside

the dome

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Radio receivers

receivers

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Radio receivers

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Radio receivers

VLBA telescope

receivers

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Radio receivers

VLBA telescope

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Radio horns

VLBA telescope

~1 meter

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Millimeter receivers

Millimeter

100GHz-300GHz

3mm-1mm

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Millimeter wave receiver

Receivers

Hat Creek Radio Observatory

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Millimeter wave receiver

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Millimeter wave receiver

Horns

Amplifiers

~0.5 m

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