Whether it's flood disasters or emergency response scenes blazing with flames, these are all testing grounds for drones to demonstrate their capabilities. How can we ensure that large numbers of drones can be accurately controlled? How can we ensure stable transmission of image data captured by drones to terminal control? Undoubtedly, "accurate signals" are the key factor in determining the success or failure of drone applications.

Applications of Crystal Oscillators in Drones
To ensure precise flight execution, drones rely not only on flight attitude, speed, and altitude parameters but also on the stable clock signal provided by crystal oscillators.

Generally speaking, crystal oscillators are used in both drone flight control systems and remote controls: the positioning module is located in the flight control system, while image transmission is used in both.

Positioning Module
Drones are subject to various environmental factors (electromagnetic interference, temperature, inclement weather, etc.) during operation. To ensure the proper operation of the positioning system and minimize positioning errors and signal loss, the crystal oscillator in the positioning module must output a precise and highly stable clock frequency. This allows the GPS, GLONASS, BeiDou, and other satellite navigation receiver chips in the positioning module to sample and process signals at precise intervals, thereby achieving synchronized reception, processing, and positioning calculation of satellite signals. To achieve precise positioning of drones, the temperature characteristic of the crystal oscillator frequency is generally required to achieve ±0.5ppm or higher to ensure acceptable positioning errors.

Image Transmission
Drone image transmission systems generally utilize the 2.4GHz and 5.8GHz frequency bands for transmission, and in some cases, 4G or 5G cellular modes are even required for image transmission. Highly stable crystal oscillators are crucial for ensuring stable image transmission. Furthermore, with the demand for 4K and 8K ultra-high-definition image quality, camera modules also require crystal oscillators with low jitter and phase noise to ensure image accuracy and reliability. Crystal oscillators with low jitter and phase noise can reduce image signal distortion and noise, improving image clarity and detail. Applications requiring high image quality require crystal oscillators with excellent jitter and phase noise performance.

In addition, crystal oscillators provide a stable local oscillator frequency, ensuring stable and reliable data transmission between the aircraft and ground control, ensuring accurate command and data transmission during flight. During flight, data transmission and reception require strict synchronization. Crystal oscillators provide a unified clock signal, enabling the transmitter and receiver in each module of the drone to precisely process and transmit data, ensuring accurate and complete data transmission and minimizing data errors and packet loss.

System Control
The flight control system can be considered the brain of the drone. Flight, hovering, obstacle avoidance, and attitude adjustments all require the use of numerous sensors. These sensors collect and transmit data, which is then analyzed and issued by the flight control CPU, which then executes various motor servo movements. Flight control modules, communication modules, and other components all need to work together. A crystal oscillator provides a unified clock signal for the entire drone system, enabling precise time synchronization and data exchange between modules to ensure the drone's overall performance and flight safety. For example, hovering a drone requires that all rotors have equal rotational speeds and generate lift equal to its own weight. This requires that all electrodes servo synchronously operate at the same frequency, with real-time synchronization based on the altitude calculated by the barometric pressure sensor.