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Link budget so far… EBNO is a symbol and does not equal E b divided by N 0 (in dB) EIRP = P t + G t Path Loss Signal to Noise ratio.

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Presentation on theme: "Link budget so far… EBNO is a symbol and does not equal E b divided by N 0 (in dB) EIRP = P t + G t Path Loss Signal to Noise ratio."— Presentation transcript:

1 Link budget so far… EBNO is a symbol and does not equal E b divided by N 0 (in dB) EIRP = P t + G t Path Loss Signal to Noise ratio

2 hz)

3 Other factors that will effect Power Received Atmosphere; this is transparent at our chosen frequency. Ionosphere; which is something that needs looking into. The Effect of tumbling which will pulsate the power and is disused briefly later.

4 Chosen frequency Information Using two frequencies we can uplink and downlink at the same time. 436MHz (down link) and 146MHz (Up link) They are both transparent to the atmosphere. They will gives us our needed bit rate. They are in the amateur bands so the licences are easily available

5 Original Transceiver (DJ-C7T/E) Specs Frequency Coverage; –Uplink: 144-145.995MHz –Down Link: 430-439.995MHz Modulation; –Uplink: 16k0F3E (FM) –Downlink: FM Output: 300mW with EBP58N / 500mW with 6Vdc power-source Power Supply Requirements: 3.7Vdc EBP58N / 3.7 - 6.0Vdc external power source Current Drain (approx) ; –Transmitting: 320mA –Receiving (squelched): 70mA –Receiving (BS-on): 19mA Operating Temperature: -10 ~ +60 degrees o C

6 Considerations for aerial Need to match aerial impedance to the impedance of the transceiver. Find the aerial length that gives the heights power output. If two frequency's are used then a trade off will be needed between them both. Decide on whether a monopole or dipole aerial would be more effective

7 Experiments That Could Be Done 1.Map transmitted power of the aerial to find any points of low power, this can show the feasibility of using a monopole. 2.Find length of aerial that transmit's the most power. Add an inductor and capacitor so the aerial impedance matches the impedance of the transceiver. 3.Calibrate Radials (if used).

8 Consider Beacon Only needs 80mW Transmitted Power therefore ~ 240mW Total Power. Can beam down house keeping data constantly. Is a good failsafe for satellite

9 Other Considerations Need to look at Signal Modulations (which is limited by choice of transceiver) If a packet System is used to transfer data or continuous stream. Data Link Protocols (which will effect the amount of data that can be transferred) Will be an analogue signal transmitting digital data


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