Video Stream Integrity for Long-Range FPV Drones
Ultra-Low-Noise Amplifiers Boost Drone Signals
(Source: Alexandra/stock.adobe.com)
Since the early 2000s, drones have captured the public imagination as an exciting way to record and transmit video footage. Prior to drones, high levels of precision and control video access were previously reserved for larger, crewed aircraft like helicopters. And while early first-person view (FPV) drones were initially used for military purposes, the trickle-down of drone technology into the consumer sector led enthusiasts to experiment with well-established analog video transmission from onboard cameras.[1] These signals could then be sent to goggles or screens to provide pilots with vivid, first-person flying experiences, which led to the wider commercial adoption of FPV drone technology in the following years.
Today, drones are an established competitive technology for the highest levels of video production, as seen in big budget films from the past several years.[2] Many FPV enthusiasts still use analog video protocols due to the low latency requirements for real-time video in high-speed drone racing, but consumer, industrial, and military drones are increasingly relying on proprietary digital protocols.
With advancements in artificial intelligence (AI), imaging sensors, and battery technology expected to drive the global drone market from $73.06 billion (USD) in 2024 to $163.60 billion (USD) by 2030,[3] choosing the right hardware for digital drone transmission systems is important when trying to meet the significant data demands. In fact, it’s important to consider how adding additional capabilities may stress the already stringent Size, Weight, and Power (SWaP) optimization requirements for maximizing flight time and payload capabilities, which are primarily set by battery capacity, system weight, and power consumption, as well as the thrust capabilities of motor systems.
In this blog, we discuss why high signal integrity becomes essential for maintaining data transmission and ensuring smooth video streams as commercial and military drones shift to digital video communications protocols, extend their flight and frequency ranges, and increasingly encounter environments filled with RF interference. In addition, we showcase an amplifier solution for next-level transmission reliability in FPV drones.
Drone Video Transmission Protocols
For early camera-equipped drones, established analog protocols like Phase Alternating Line (PAL) and National Television System Committee (NTSC) were an obvious choice for video transmission in FPV systems. NTSC’s low cost, low latency, and video transmission at up to 30 frames per second[4] enabled pilots to experience drone flight with quality comparable to analog broadcast television and video games before the high-definition (HD) era.
But with limited resolution, such as the 625 scan lines for PAL, for example, analog protocols are unsuitable for the HD video streaming typical of cinematic filming, military reconnaissance, or surveying applications. By shifting to digital protocols, drone operators can combine higher-resolution video with other data communications, such as telemetry data, metadata, and even drone control signals. Like most digital communications, these protocols also offer increased data security with greater throughput than analog transmissions.
Typically, drone-centric digital protocols like Crossfire, Express Long Range System (ExpressLRS), HDZero, and DJI SDR are proprietary by manufacturer, but they all use similar unlicensed 2.4GHz, 5.1GHz, and 5.8GHz bands for communication, with some based on Wi-Fi® standards. However, many advanced drone applications present issues for reliable communication, as drones are expected to operate at great distances from their pilot, sometimes more than 15 miles for enterprise-grade systems.[5] In addition, considering global drone video transmissions means using technology capable of transmitting at 600MHz and 1400MHz. Here, high signal integrity becomes essential for maintaining control and ensuring smooth video streams across long distances.
Amplifying Drone Signals for Reliable Performance
The presence of buildings, trees, or unrelated RF signals like commercial Wi-Fi networks can interfere with drone communications and cause issues such as limited range,[6] poor quality and inconsistency in video streams, or loss of vital control and telemetry data.[7] For applications where drones are beyond visual line of sight (BVLOS) for the pilot, which is common in military use cases, these issues can be especially prevalent. Not surprisingly, signal amplification plays a critical role in drone transmissions for real-world use cases such as BVLOS.
For the frequency bands commonly used in consumer and military drone designs, Qorvo offers an ultra-low-noise solution for boosting vital signals. The QPL9547 (Figure 1) is a high-linearity, ultra-low-noise amplifier optimized for 5G Massive multiple-input, multiple-output (MIMO) applications, making it great for the complex data needs of modern drones.
Key features of the QPL9547 include:
- 0.1GHz to 6.0GHz frequency range to support a wide range of wireless protocols
- Ultra-low 0.3dB noise figure for clear signal amplification—essential when drones reach the limits of their control range
- 19.5dB gain at 1.9GHz to provide ample boost to weak signals
- Adjustable bias for linearity optimization to prevent distortion and support high data rates
- Unconditional stability for predictable operation in harsh environments and ever-changing flight conditions
Figure 1: The Qorvo QPL9547 ultra-low-noise amplifier provides 19.5dB gain across a 0.1GHz to 6.0GHz frequency range, supporting a wide range of transmission protocols for high-definition FPV drones to ensure video stream and control data integrity. (Source: Mouser Electronics)
A single positive supply from 3.3V to 5.0V enables this amplifier to easily integrate with standard voltage rails. To further aid SWaP optimization, the QPL9547 is available in a 2 × 2mm QFN8 package with minimal external component requirements. The −40°C to +85°C operating temperature range makes this device suitable for most outdoor environments, catering to a wide range of drone deployments from alpine rescue missions to nature filming in desert climates.
In addition to drone applications, the QPL9547 amplifier is well suited for a wide range of high-throughput signal applications, including:
- Repeaters and distributed antenna systems
- Frequency-division duplex and time-division duplex systems
- Mobile infrastructure
- General-purpose wireless applications
Getting Started with the Qorvo QPL9547
When integrating the QPL9547 amplifier into designs, the QPL9547EVB-01 evaluation board enables easy testing. This platform is shown in Figure 2 alongside an example application circuit that can be rapidly incorporated into existing designs for faster product development. It also provides access to key pin signals to support detailed performance characterization.
Figure 2: The Qorvo QPL9547EVB-01 evaluation board and application circuit diagram for testing the QPL9547 amplifier. (Source: Mouser Electronics)
Next-Level Transmission Reliability for FPV Drones
With so much data moving between modern drones and their controllers, high-throughput digital protocols offer a distinct advantage over analog video standards when it comes to HD video streaming and securing transmission lines. As drone systems continue to push the boundaries of flight range and video quality, high signal integrity becomes even more important for reliable operation.
Qorvo offers an extensive portfolio of products ideal for drone solutions. The QPL9547 ultra-low-noise amplifier from Qorvo provides a compact solution to boost long-distance digital drone signals without impeding SWaP optimization. With these devices, drone designers can enable smoother, ultra-HD video streams in challenging long-range and BVLOS settings, whether military, industrial, or cinematic in nature.
Sources
[1]https://nebodron.com.ua/en/articles-en/the-history-of-fpv-drones-from-inception-to-present-en
[2]https://ymcinema.com/2021/09/13/red-notice-is-a-proof-that-cinema-fpv-conquered-netflix/
[3]https://www.grandviewresearch.com/industry-analysis/drone-market-report
[4]https://www.smp-ltd.com/blog/post/whats-the-difference-between-ntsc-and-pal
[5]https://uavcoach.com/how-far-drone-fly/
[6]https://coptrz.com/blog/how-far-can-a-drone-fly-understanding-range-and-factors-affecting-it
[7]https://www.mepsking.shop/blog/how-to-handle-fpv-drone-signal-loss-and-interference.html
Author
Brandon Lewis has been a deep tech journalist, storyteller, and technical writer for more than a decade, covering software startups, semiconductor giants, and everything in between. His focus areas include embedded processors, hardware, software, and tools as they relate to electronic system integration, IoT/industry 4.0 deployments, and edge AI use cases. He is also an accomplished podcaster, YouTuber, event moderator, and conference presenter, and has held roles as editor-in-chief and technology editor at various electronics engineering trade publications.
When not inspiring large B2B tech audiences to action, Brandon coaches Phoenix-area sports franchises through the TV.