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− | == Introduction ==
| + | {{COMMON-CANSAT-ANTENNA}} |
− | What ever you do, the antenna is always one of the most sensitive component when working in the radio area.
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− | The following schema shows how to wire the RFM69HCW to transmit data.
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− | [[Fichier:ENG-CANSAT-RFM69HCW-TEST-00.jpg|520px]]
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− | As you can see, the antenna is made of a simple wire.
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− | Remove the wire and the data would not transmit at 1 meter of distance, even on the same desk!
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− | Remember, '''the antenna is the key to transmit data over a long distance!'''
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− | == Antenna connector ==
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− | The radio modules usually offer a spot to solder antenna.
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− | With the RFM69HCW the antenna spot allow you to connect an antenna in 3 different ways.
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− | [[Fichier:ENG-CANSAT-RFM69HCW-Antenna.png|240px]]
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− | Later on, you would focus on antenna choice:
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− | * A wire inside the antenna hole (also said a ''wire dipole'' or ''simple dipole'').
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− | * A {{pl|1418|µFl connector}} to plug antenna.
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− | * A {{pl|1419|PCB SMA connector}} also to plug other kind of antenna.
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− | The cheapest antenna is the wire antenna (''simple dipole'') and the best option is the SMA connector (also mode heavy).
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− | The {{pl|1418|µFl connector}} (also named uFl) is looking to this:
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− | [[Fichier:ENG-CANSAT-RFM69HCW-TEST-uFL-connector.jpg|150px]]
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− | A {{pl|1419|PCB SMA connector}} is looking to this:
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− | [[Fichier:ENG-CANSAT-RFM69HCW-TEST-SMA-connector.jpg|150px]]
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− | == Yagi Antenna ==
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− | While reading [https://arduino103.blogspot.com/2018/08/ballons-meteorologiques-tout-savoir-sur.html some resources on the QSO magazine] (Magazine from Belgian Radio Amateur Association written in dutch and french), we did discover a Yagi Antenna tuned for 433Mhz.
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− | [[Fichier:ENG-CANSAT-ANTENNA-10.png|640px]]<small><br />Source: QSO Magazine via [https://arduino103.blogspot.com/2018/08/ballons-meteorologiques-tout-savoir-sur.html this publication] - '''click to enlarge'''</small>
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− | This antenna was engineered from the "[http://df.mchobby.be/ballon-meteo/cheapyagy.pdf Cheap Yagy]" (''pdf''), issue from the "[http://www.wa5vjb.com/yagi-pdf/cheapyagi.pdf Controlled Impedance 'Cheap' Antennas]" article written by Kent Britain WASVJB.
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− | A simple rule of three can be used to adapt the antenna to other frequencies (the antenna was already adapted from a 432 Mhz design).
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− | === 6 or 11 elements ===
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− | The Yagi antenna showed here upper does have 6 elements.
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− | From a deeper read of the [https://arduino103.blogspot.com/2018/08/ballons-meteorologiques-tout-savoir-sur.html QSO magazines series], we learned that 6 elements Yagi can offer a gain up to 11.2 dBi.
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− | It seems that the 11 elements Yagi ([http://df.mchobby.be/ballon-meteo/cheapyagy.pdf see original document]) '''will double the gain'''. Whoaw!!!
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− | == CanSat and Antenna ==
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− | As specified by the CanSat settlement, everything should be contained within a defined volume (the Can).
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− | So, the antenna should also fit into the volume.
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− | However, '''once the can is released in the air, your project can deploy an antenna'''.
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− | A well designed antenna for sending the data would also reduce the error ratio on the ground station.
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− | == Getting Help for Antenna ==
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− | Designing and testing an antenna for long distance communication is an intensive work.
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− | You could find some help from our Radio Amateurs friends.
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− | To locate a [http://map.mchobby.be Radio Amateur Club] near of your home then have a look [http://map.mchobby.be the "Maker's Maps"] owned at MC Hobby.
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− | [[Fichier:ENG-CANSAT-ANTENNA-20.png|link=http://map.mchobby.be]]
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− | A '''yellow mark''' indicates the Radio Amateur clubs.
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| {{ENG-CANSAT-TRAILER}} | | {{ENG-CANSAT-TRAILER}} |