HD digital wireless image transmission transmitter

HD digital wireless image transmission transmitter ST220 built-in coding board、COFDM modulation module、Small size PA power amplifier module，The whole machine adopts CNC aluminum alloy shell，small volume，Other standards can be customized，High transmission resolution，Long launch distance。

• COFDMmodulation。
• H265/H264 video encoding，Default up to 1080P/I @60fps。
• AES256 encryption。
• Support non-line-of-sight high-speed mobile transmission。
• center frequency、Configurable convolutional coding ratio、Transmission stream, etc. can be configured。

ST220Main technical specifications

ST220 transmitter can be matched with SR300 receiver、SR110 receiver、SR200 receiver use。When ST220 transmitter and SR300 receiver wirelessly transmit H265 video point-to-point，Video delay is generally between 200~300ms(Does not include the camera's own delay)。ST220 transmitter with SR110 receiver，When transmitting in H264 low-latency mode，Video delay is generally between 50~130ms(Does not include the camera's own delay)。

ST220Transmitter interface signal

ST220 transmitter

AV input interface：

SD input interface，4PIN 1.5mm pitch socket，Audio supports Mic in or Line in input(Specified at the factory)。PAL or NTSC format can be set through the parameter panel。

CFG interface：

Configure serial port(Control-uart)，4PIN 1.5mm pitch socket，TTL 3.3V level。The 5V signal is used to supply power to the reference panel when it is connected to the reference panel。

Data interface：

One-way transparent data transmission serial port(Data-uart)，The serial port data will be unidirectionally transmitted to the data serial port of the corresponding receiver through the COFDM wireless link。3PIN 1.5mm pitch socket，The default shipment is TTL 3.3V level，It can also be specified as a standard RS232 level serial port when shipped。

work indicator：

Overview

The ST220 HD Digital Wireless Image Transmission Transmitter is a compact, high-performance device designed to deliver reliable wireless video transmission for professional applications. By integrating a built-in COFDM modulation module, an H.265/H.264 video encoding board, and a small-size PA power amplifier module, the ST220 achieves stable long-distance video transmission in a rugged, lightweight package.

The transmitter adopts a CNC aluminum alloy housing, ensuring durability, excellent heat dissipation, and lightweight design suitable for airborne applications. With support for high-definition (HD) and standard-definition (SD) video inputs, configurable transmission parameters, and multiple frequency bands, the ST220 offers a flexible solution for drone operations, field broadcasting, surveillance, and other wireless video applications.

Paired with receivers such as the SR300, SR110, or SR200, the ST220 enables real-time video transmission with selectable latency modes. Depending on configuration, latency can be reduced to as low as 50–130 ms for critical low-delay applications or maintained at 200–300 ms in high-compression modes for bandwidth optimization.

Key Features

• COFDM Modulation: Ensures robust, stable transmission in both line-of-sight (THE) and non-line-of-sight (NLOS) environments.
• Video Encoding: Supports H.265 (hope) or H.264 (AVC) encoding, with default transmission up to 1080P/I @ 60 fps.
• Encryption: Built-in AES-256 encryption guarantees secure video and data links.
• Flexible Video Input: Standard HDMI input for HD signals, and CVBS/analog input for SD video sources. Automatic input detection with HDMI preference, or configurable for AV priority. Optional dual-input encoding available.
• Transparent Data Transmission: One-way transparent serial data channel (UART), configurable for TTL 3.3V or RS232 levels, enabling simultaneous data communication along with video.
• Customizable Frequency: Wide range of selectable frequency bands between 200–860 MHz, with configurable center frequency and fine-tuning step of 1 kHz.
• Transmission Power Options: Selectable 1 W (30 dBm) or 2.5 W (34 dBm) RF output for extended range.
• Audio Support: Embedded HDMI audio or analog stereo audio input (Mic/Line-in selectable).
• Rugged Design: CNC-machined aluminum shell provides heat dissipation, durability, and compactness.
• Compact & Lightweight: Size 104.5 × 50 × 27 mm, weight less than 140 g, making it suitable for drone payloads.
• Configurable Parameters: Modulation settings (bandwidth, coding rate, constellation), working frequency, and FEC ratios are fully adjustable via configuration tools.
• Low Latency Modes: When paired with compatible receivers, latency can be as low as 50 ms, suitable for FPV, drone piloting, or real-time monitoring.

Technical Specifications

Wireless Modulation & Transmission

• Modulation: COFDM
• Bandwidth: Adjustable from 1 MHz to 8 MHz
• Constellation: QPSK, 16QAM, 64QAM
• FEC (Forward Error Correction): 1/2, 2/3, 3/4, 5/6, 7/8
• Guard Interval: 1/32, 1/16, 1/8, 1/4
• Configurable coding ratio: 2K

Working Frequency

• Standard Bands:
  • 300–360 MHz
  • 350–400 MHz
  • 450–500 MHz
  • 520–560 MHz
  • 580–620 MHz
  • 680–720 MHz
  • 820–860 MHz
• Customization: Other frequencies from 200–860 MHz available upon request
• Step size: 1 kHz configurable center frequency

Transmit Power

• 1 W (30 dBm) or 2.5 W (34 dBm) selectable

Video & Audio Processing

• Video Inputs: HDMI (HD) and CVBS analog (SD)
• Supported Formats:
  • 1080P/I @ 60/50 fps
  • 720P @ 60/50 fps
  • PAL (720×576@50i)
  • NTSC (720×480 @ 60i)
• Video Encoding: H.265 / H.264
• Audio Input: HDMI embedded or analog audio (Mic-in/Line-in selectable)
• Audio Format: AAC, 16-bit stereo

Interfaces

• HDMI Input: Standard HDMI port
• SD Video Input: 4-pin, 1.5 mm pitch connector
• Transparent Data UART: 3-pin, TTL 3.3V (default), Only one of HDMI and SDI input can be selected
• Configuration Port: 4-pin, TTL 3.3V, compatible with parameter panel or PC connection
• Power Input: channel RS232 uart (DC 12V, 11–13V range)
• Antenna: SMA connector (male, inner pin)

Indicators

• Power LED: Red, always on when powered
• Link LED: Green, blinks during wireless transmission activity

Power & Consumption

• Supply Voltage: DC 12V (11–13V)
• Consumption:
  • ≤15 W @ 1 W RF output
  • ≤23 W @ 2.5 W RF output

Physical

• Size: 104.5 × 50 × 27 mm (excluding connectors and mounting points)
• Weight: <140 g

Performance with Receivers

• ST220 + SR300 Receiver:
  • Point-to-point H.265 transmission
  • Typical latency: 200–300 ms (excluding camera delay)
• ST220 + SR110 Receiver:
  • Low-latency H.264 transmission mode
  • Typical latency: 50–130 ms (excluding camera delay)
• ST220 + SR200 Receiver:
  • Standard COFDM reception with configurable settings

Applications

The ST220 HD digital wireless image transmission transmitter is designed for professional video transmission in demanding environments. Its combination of compact design, high-resolution support, and configurable transmission options make it suitable for:

• Industrial & Commercial UAVs: Long-distance wireless video backhaul for drones in mapping, inspection, and surveying.
• Broadcast & Media: Wireless camera links for live events, sports, and news gathering.
• Security & Law Enforcement: Mobile video transmission for surveillance vehicles, field operations, or public safety drones.
• Search & Rescue Operations: Reliable video feeds in disaster zones or remote areas.
• Defense & Reconnaissance: Tactical UAV or ground unit video transmission with secure AES-256 encryption.

Optional Configurations

• Frequency Bands: Customizable bands from 200–860 MHz.
• Data Port: Configurable as TTL (default) or RS232.
• Video Input Priority: HDMI or AV (factory-configurable).
• Dual-Video Input Mode: Optional dual-input encoding and transmission.
• Transmit Power: 1 W (low power) or 2.5 W (high power).
• Receiver Compatibility: Compatible with SR110, SR200, SR300 models depending on latency and resolution needs.