Cofdm Spiral filter
Helical Filter Cofdm Spiral filter
Features
Specification
| Item | Parameter |
| Frequency | 830-870Mhz |
| Insertion loss | ≤1.2db |
| Return loss | ≥16db |
| Out-of-band rejection | ≥60dB@760MHz
≥60dB@940MHz |
| Connector | SMA-K |
| Weight | 0.15kg |
| Dimensions | 89 * 32 * 20mm |
COFDM Spiral Filter – High-Performance Helical RF Filter for Wireless Video Transmission
The COFDM Spiral Filter, also known as a Helical Filter, is a high-performance RF filtering solution designed specifically for COFDM (Coded Orthogonal Frequency Division Multiplexing) wireless transmission systems. Built with precision engineering and advanced resonator design, this filter provides excellent selectivity, low insertion loss, and high out-of-band rejection, ensuring reliable operation in complex RF environments where interference and signal clarity are critical.
As modern wireless communication and video transmission systems expand into increasingly crowded frequency bands, the need for highly selective RF filtering has become essential. The COFDM Spiral Filter offers a proven and effective way to achieve stable performance, enabling high-quality, real-time wireless video transmission even in environments with strong interference. With its compact form factor, robust design, and optimized electrical performance, this filter is an ideal component for professional video transmission equipment, UAV/Drone data links, public security communication systems, and other mission-critical wireless applications.
Key Features and Advantages
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Spiral / Helical Filter Design
The filter uses a helical resonator structure, which provides a sharp frequency response, excellent selectivity, and stable performance across the designed frequency range. Helical filters are known for their ability to achieve high Q-factor performance in a compact size. -
Optimized for COFDM Systems
Specifically designed to work seamlessly with COFDM wireless video transmission equipment, the filter ensures minimal distortion to the modulated signal while effectively suppressing out-of-band interference. -
Low Insertion Loss
With an insertion loss of ≤ 1.2 dB, the filter allows most of the desired signal to pass through without significant attenuation, preserving signal strength and transmission quality. -
High Out-of-Band Rejection
The filter provides rejection of ≥ 60 dB at 760 MHz and ≥ 60 dB at 940 MHz, ensuring that undesired signals outside the 830–870 MHz band are effectively eliminated, protecting system integrity. -
Compact and Lightweight
Measuring only 89 × 32 × 20 mm and weighing just 0.15 kg, the filter is designed for easy integration into portable and airborne systems, including drones and handheld devices. -
Reliable RF Performance
With a return loss of ≥ 16 dB, the filter demonstrates excellent impedance matching, reducing reflections and improving overall transmission efficiency. -
Durable Connectors
Equipped with SMA-K connectors, the filter is compatible with standard RF systems, ensuring reliable connectivity and long service life.
Technical Specifications
| Item | Parameter |
|---|---|
| Frequency Range | 830 – 870 MHz |
| Insertion Loss | ≤ 1.2 dB |
| Return Loss | ≥ 16 dB |
| Out-of-Band Rejection | ≥ 60 dB @ 760 MHz |
| ≥ 60 dB @ 940 MHz | |
| Connector | SMA-K |
| Weight | 0.15 kg |
| Dimensions | 89 × 32 × 20 mm |
Application Scenarios
The COFDM Spiral Filter is widely used in a variety of industries and application fields that require stable, interference-free wireless video and data transmission:
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UAV and Drone Video Transmission
For drones used in aerial photography, mapping, public security, and industrial inspection, clear and reliable wireless video transmission is essential. The filter helps eliminate interference from nearby frequency bands, ensuring uninterrupted video streams during flight operations. -
Public Security and Law Enforcement
Police, fire departments, and emergency response teams often rely on wireless COFDM systems to transmit live video feeds from field units to command centers. The spiral filter ensures stable communication, reducing the risk of interference in critical missions. -
Broadcasting and Media Production
In outdoor and event broadcasting, wireless video links are subject to interference from multiple RF sources. The filter provides clear channel isolation, improving image quality and transmission stability for professional broadcasting. -
Military and Defense Applications
In reconnaissance, tactical communication, and field monitoring systems, reliable data links are critical. The COFDM Spiral Filter offers secure and stable RF performance, even in challenging electromagnetic environments. -
Industrial Monitoring and Inspection
For wireless video systems used in oil fields, mining operations, and infrastructure inspection, the filter helps maintain high signal quality, reducing downtime and improving operational efficiency. -
Traffic Management and Surveillance
In intelligent transportation systems and city surveillance networks, clear video transmission is essential for monitoring and safety. The spiral filter minimizes cross-channel interference, ensuring consistent image quality.
Why Choose a Spiral (Helical) Filter?
Helical filters are widely recognized for their compact design, high selectivity, and excellent stopband performance. Compared to cavity filters or lumped-element filters, spiral filters strike a balance between performance and size, making them especially suitable for portable and airborne applications.
The COFDM Spiral Filter is tailored to COFDM-based video systems, ensuring that the orthogonal subcarriers within the signal remain unaffected by filtering while out-of-band noise and interference are strongly suppressed. This makes it a superior choice for demanding wireless environments.
Design Benefits
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High Q-Factor: Helical resonators provide sharp roll-off characteristics.
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Frequency Stability: Designed for consistent operation across 830–870 MHz.
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Integration-Friendly: Compact dimensions make it easy to install in custom enclosures.
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Long Service Life: Durable construction and connectors withstand frequent use.
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Wide Compatibility: Works with COFDM transmitters, receivers, and other RF front-end systems.
Conclusion
The COFDM Spiral Filter (Helical Filter) is a robust and reliable RF component engineered to meet the demands of modern wireless video and data transmission systems. Its combination of low insertion loss, excellent out-of-band rejection, and compact lightweight design makes it the perfect choice for applications where clarity, reliability, and performance cannot be compromised.
Whether deployed in UAVs, public security, broadcasting, or industrial monitoring, this filter ensures that your COFDM system delivers uninterrupted, high-quality wireless video transmission. For engineers, system integrators, and equipment manufacturers seeking a proven solution to RF interference challenges, the COFDM Spiral Filter offers an outstanding balance of performance, size, and durability.
