Pharos: Smart Antenna for Drones
Pharos: Smart Antenna for Drones
The Pharos Smart Antenna will increase the range of your 5.8 GHz data link by 2.5x to 5x.
The Pharos Smart Antenna will increase the range of your 5.8 GHz data link by 2.5x to 5x. Read more
About this project
Pharos antenna is the first antenna for drones and robotic platforms that forms a directional, high gain beam and keeps it always pointed to the drone control station, regardless of the drone’s motion. It can be used on both sides of the link, the ground control station and the drone. It is an electronically-controlled tracking antenna with no moving parts.
The Pharos is a newly-developed smart antenna. Unlike conventional omni-directional antennas that waste energy in all directions, the Pharos concentrates the available power where you need it most. Working in conjunction with Pixhawk autopilot (a version with its own autopilot is being also developed), the antenna activates the side facing your UAV, boosting reception and range. A second Pharos can also be used on the aircraft, quadrocopter or UAV, keeping ground control in aim at all times. The Pharos is also circular-polarized, granting immunity to polarization losses and multipathing signals, an optimum choice for challenging environments.
The Pharos antenna is the evolution of the motorized tracking antennas as it has no moving parts and it’s much lighter and smaller than the existing motorized tracking antennas. It’s so small and light-weighted that now you can put a tracking antenna on your drone or robot, boosting its datalink to unmatched performance and without sacrificing endurance.
Pharos antenna prototypes presented at the AUVSI expo New Orleans 2016
- 4 x 5.8 GHz RHCP Xair antennas
- Switching time: 5 microsec (μS)
- Gain (each antenna): 10dBi
- Insertion loss: 0.8 dB
- SWR: 1.2:1
- Axial ratio: 1 (perfect)
- Beam: 120deg. Beam @-3dB**: 68deg.
- Interface connectors: Controller PCB (MCX Jack), Enclosed antenna (SMB Jack)
- Current draw: 20mA
- 4 x indicator LEDs
- 1 x 100mil (2,54mm) 3-pin header (servo connector) for signal, power and ground
- Antenna Radome: Makrolon 6267 XC, RF optimized plastic Enclosure: 7x7x7cm
- Weight: 65 gr. (2.3 oz)
Antenna gain and beam diagrams
Horizontal pattern of one of the 4 single Pharos elements
Vertical pattern of one of the 4 single Pharos elements
Pharos single element (blue) gain and coverage comparison with an omni antenna (red)
Pharos all antennas (blue) gain and coverage comparison with an omni (red) antenna
PHAROS ANTENNA APPLICATIONS
Use the Pharos antenna with a 5.8GHz video transmitter on the Pixhawk equipped drone (aerial side for improving video transmission)
Use the Pharos antenna with a 5.8GHz video receiver on the Ground by interfacing it to a Pixhawk controller (Ground side for improving video reception)
Use the Pharos antenna in conjunction with a Microhard 5.8GHz modem on both the drone and the GCS for improving both telemetry and video streaming.
The Pharos antenna can be used with any type of drone i.e. aerial, land based (rovers) or maritime (boats) to extend the range of your system. It is suitable for any robotic platform that needs an extended and robust data link.
ANTENNA CONTROL MODES
Manual Antenna control
Activate each one of the 4 antenna panels by selecting numbers 1 through 4 on a terminal program (DroidTerm shown above on an Android smartphone)
Semi-Manual Antenna Control (geo-registered activation)
Activate each one of the 4 antenna panels by moving the target icon around the antenna icon on a 3D map. The antenna panel that faces the target icon will activate. You can enter manually the antenna location (or use a GPS sensor), the antenna orientation (or use a compass sensor), the target location (or use a GPS sensor i.e. GPS beacon).
Automated antenna control
The antenna panel that faces towards the drone HOME (or RTL) point will activate regardless of the drone location or orientation.
We've got real working prototypes (everything you've seen in the video is real, no CGI) and we're ready to take the next step.
By raising $25,000 on Kickstarter, we will be able to conduct our first production run. After the Kickstarter campaign is successfully completed, the Pharos antenna retail pricing on our website will be $249. We offer the Pharos antenna to our Kickstarter backers at $159 (36% off) in a single antenna and $299 (40% off) in a pair of two antennas, so that we will get the opportunity to bring this unique, new product to life.
We believe that the Pharos antenna is not just a trend, but an advanced technology brought to the consumer level applications. This concept opens a whole new world of possibilities in the robotics and wireless communications fields as it substantially optimizes the wireless links quality and range while keeping the form factor minimized. We thought of hundreds of applications where this technology applies but you, the backers, will think of even more and we are eager to listen and create more versions.
Omni-directional antennas are used extensively with drones since they radiate and receive in all directions. The omni antennas were the only choice for unmanned systems as the drones are constantly changing directions and orientations due to their motion.
Only an omni antenna ensures that the drone’s ground station will be constantly under the antenna uniform coverage, regardless of the drone’s flight or ground track. Omni antennas might offer wide spatial coverage, but this comes at a cost. The main disadvantage of the omni antennas is their reduced gain, since the radiated power is distributed uniformly in all directions. Only a fraction of the radiated power is exchanged between the drone and its ground station and the biggest part gets wasted in all other directions. Spreading the RF energy evenly all around is not an efficient use of the limited available power. That’s the main reason the data link between the drone and its ground station becomes unstable, weak, and finally breaks at ranges beyond 1 or 2 km with the current technology antennas. This is the cost for being able to cover all directions around the drone or the ground station.
It is an axiom that if we wish to increase the antenna’s radiated power (known as antenna gain), we have to reduce its radiation beam angle. As the beam angle decreases, the gain increases. This provides a greater coverage distance, but with a reduced coverage angle. If for example, we use a directional antenna on board the drone, it is not possible to keep the directional beam constantly pointed to the ground station as the drone moves arbitrarily. As soon as the drone’s antenna beam points away from the ground station, the link will break.
Pharos Antenna Versions
The Pharos Antenna can be used on both the Drone and the Ground control station (GCS).
To use the Pharos Antenna with your Drone:
1. Plug the antenna 3-pin connector using a servo cable to the Pixhawk autopilot AUX-2 port. It draws power and it is controlled by the Pixhawk AUX-2 signal pin
2. Plug your drone transmitter to the antenna SMA connector (SMA plug).
- The Pharos Antenna will use the drone’s Home Point as a reference point for diverting its beams. As the antenna beams will be directed towards the Home point, naturally, the Ground Control Station shall be in that area.
- A custom Pixhawk firmware is offered that adds the Pharos Antenna functionality on top of the standard Pixhawk firmware.
To use the Pharos antenna with your Ground Control Station:
1.Use a Pixhawk autopilot with external GPS/compass and plug the Pharos antenna to the Pixhawk autopilot AUX-2 port just like the aerial version.
2.Plug your drone receiver to the antenna SMA connector (SMA plug).
As soon as you establish a telemetry link between the GCS and the drone using the Mission Planner the GCS Pharos antenna will divert its beams towards the drone.
- The Pixhawk used on the GCS side requires loading a custom firmware version to it. This custom version will be available for download.
- A firmware version that runs on the inexpensive Teensy board will also be offered with schematic diagrams for connecting your own GPS and IMU as an alternative GCS antenna controller.
Tip: To get the most out of the Pharos Antenna, you can use the 5.8 GHz Microhard Digital Data Link modems for streaming both telemetry and video through a single modem. This way, only one antenna is used for each modem for extending the range for both video and telemetry through a single, tiny device as shown below.
How to use the Pharos Antenna with the Microhard modems
We have developed a carrier board for the 5.8GHz microhard modem that allows you to connect both the telemetry serial channel and an IP camera and stream both through the same channel. This set up, allows using a single Pharos antenna for streaming both video and telemetry! The Pixhawk autopilot and IP cameras can be plugged directly as they are natively supported (plug-n-play) by the modem carrier board. To use an analogue camera you need to inject an analogue-to-IP converter in between (offered as an optional accessory). The schematic below shows how to connect the Microhard modem carrier board to the Pixhawk autopilot and an IP or analogue camera on your drone and on your Ground Control station to stream both video and telemetry using a single modem on each side and a single Pharos antenna.
The benefits of this set-up:
Reduced weight and size as a single modem and a single antenna is used for both video and telemetry on each side (no separate radios and antennas for telemetry and video). Extreme data link range and data quality for both video and telemetry as this set-up combines both data links into a single stream that is transmitted through the optimized Pharos digital antenna. No moving parts (i.e. motors) for tracking antennas on both the drone and the GCS. The Pharos digital technology ensures robustness and ease of use on both ends. As the video received by the GCS laptop is digital by nature (or digitized through the optional analogue-to-IP video converter), it can be used in a variety of new applications i.e. image processing, object recognition and tracking, etc.
10.6 Km video and telemetry range test with Pharos 5.8GHz antenna
What's our manufacturing timeline?
The Pharos antenna is being made and will ship from the USA, Canada and Greece EU. We've included the cost of shipping into the price of the Kickstarter Rewards Tiers. For the duration of the Kickstarter campaign, we will also offer the Pharos control software application for free. This application allows pointing the antenna beams to any geographic location desired by simply clicking on the location on the map and several other control modes.
The Arduino firmware for manual antenna operation plus the Pixhawk firmware required for automated antenna operation will be available at github for download by the end of the campaign. As with all Kickstarter Projects, this price does not include the customs fees, duties and/or taxes you might incur when importing products into your state or country. We cannot pay these fees for you. For obvious reasons we are not allowed ship to Iran, Cuba, North Korea, Sudan, Syria.
The Pharos project is a collaboration between ADCOR MAGnet Systems and TrueRC Canada. If our Kickstarter campaign is successful, we will look to create more advanced antenna technology in the future.
Risks and challenges
In our opinion, we face two risk factors:
(1) We have identified and vetted our suppliers of printed circuit boards. We will be dependent on them for timely delivery of the components. Any delay from them in the delivery of the components could result in a delay of delivering the Pharos Antenna to our Kickstarter backers. We will try to further mitigate the risk by identifying other suppliers during the Kickstarter campaign duration.
(2) The second risk is successful delivery of the Pharos Antenna systems. This risk is mitigated because we have access to a full-blown manufacturing, assembly, and logistics facility which we will use to manufacture, package, and ship the Pharos Antennas.Learn about accountability on Kickstarter
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