Bolt 4K features a brand new chipset that makes the system better at handling channel interference while producing a sharper, clearer image, whether you’re transmitting in HD or 4K. While maintaining this quality and connectivity is straightforward in an ideal situation, this is rarely the case on real sets. With the right antenna configuration and antenna placement, you can maximize your ability to maintain a robust signal in a variety of production environments.
Before deciding which antenna configuration to use, it helps to understand two concepts behind the RF theory: MIMO and RF propagation.
MIMO (Multiple Input & Multiple Output) refers to the amount of parallel RF streams being transferred between the transmitter and receiver. Each RF signal’s path from the transmitter antennas to the receiver antennas will vary, so more paths (or antennas) will increase the receiver’s chances of successfully decoding the transmitter’s signal.
RF propagation refers to the way in which RF signals travel from the transmitter to receiver. Two fundamental properties of RF propagation that ultimately govern the strength and quality of your signal are gain and diversity.
Gain refers to the consolidation of transmitted signals into a “focused” or directional beam, and can be achieved with the use of directional antennas like the Bolt 4K Panel Array Antenna. Omnidirectional antennas, like the “V” antennas, typically have lower gain as the transmit/receive pattern covers all directions, while a directional antenna will have much higher gain in a particular direction.
Diversity refers to the different signal paths between a transmitter and receiver. Diversity allows your receiver to combine signals with varying degrees of obstruction into one robust signal. In an indoor or studio environment, the RF signals from the transmitter are reflected off the walls, ceiling, and other obstructions before reaching the receiver, helping to achieve diversity.
Teradek offers three different antenna types that can be combined to get the best performance out of your Bolt 4K in different scenarios.
Vertically polarized omnidirectional antennas (“V” Antennas)
V Antennas are included as standard equipment with your Bolt 4K. They offer good performance in a wide variety of short-to-medium range situations when quick setup and flexibility is key. The antennas radiate signals in all directions out of the sides of the antenna – imagine a donut surrounding the antenna – so there are the fewest restrictions on antenna placement. Just make sure to keep them visible to the transmitter!
V antennas are ideal for achieving diversity indoors. Once you move outdoors with the V antennas, the RF signals travel in a similar or identical manner towards the receiver, weakening diversity.
Horizontally polarized omnidirectional antennas ("H" antennas)
For Bolt 4K, we designed special horizontally polarized antennas for use with the V antennas. Using a pair of H and a pair of V antennas on the TX improves the diversity characteristics of the system by combining the two perpendicular polarizations. For this H+V antenna configuration, two H antennas should be used at the TX and two at the RX as pictured. This configuration should allow for better reception and better video quality in medium-range situations and/or when the environment will create a lot of reflections for the wireless signal.
The combination of H and V antenna signals achieves better diversity than V antennas alone, especially while shooting outdoors. H antennas cause the RF signal from the transmitter to propagate in a perpendicular manner compared to the vertical signal from the V antenna.
Array 4K Panel Antenna
Your Bolt 4K receiver (if equipped with a dual battery mount) can attach to the back of an Array 4K Panel Antenna, which is a directional antenna with a receive pattern that varies based on its distance from the transmitter. The panel antenna enables Bolt 4K MAX to reach its full 5,000 ft. range, and while it doesn’t add range to your 750 or 1500 systems, it focuses the receiver’s antenna elements and increases gain in front of the panel. If you’re shooting outdoors, using a panel antenna to direct your signal should improve performance, especially for ranges greater than 1,500 ft.
The Panel antenna has both vertical and horizontal antenna connections (two H, five V), and your TX antenna configuration will determine which RP-SMA connector to connect to the left and right antennas on the receiver.
However, your antennas are only as good as how you place them.In most cases, the ideal position for the transmitter and receiver antennas is perpendicular to the ground -- straight up and down. If the transmitter is at an angle or on its side, antennas should be arranged so that they point up. Pointing the antennas in any other direction re-orients the radiation pattern and may reduce performance. For situations where the ideal antenna placement just isn’t possible, you can relocate their position on your camera with our antenna extension kit.
Optimizing your wireless performance and getting the most of Bolt 4K is as simple as correctly placing your antennas and understanding when to use what antenna configuration. No matter which antenna you use, Bolt 4K still produces a sharper image and handles channel interference over longer ranges better than ever before.