Частота спірального смугового фільтра Радіочастотні налаштування частоти 340 МГц

Частота спірального смугового фільтра Радіочастотні налаштування частоти 340 МГц

Helical filters are a critical component in modern RF and microwave systems, providing selective frequency filtering with excellent performance in terms of insertion loss, rejection, і стабільність. The Helical Bandpass Filter (336MHz–344MHz) is designed for high-performance applications where precise frequency control and signal purity are essential. With its robust design, low loss, and high rejection characteristics, this filter is widely used in communication systems, broadcasting equipment, military radio, and various wireless transmission solutions.

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Огляд продукту

The Helical Bandpass Filter is a compact and reliable RF filter specifically tuned to operate within the 336MHz to 344MHz frequency range. It is engineered to allow only the desired signals within this band to pass while effectively attenuating unwanted frequencies outside the range. Built with high-quality materials and advanced helical resonator technology, this filter delivers superior electrical performance in demanding environments.

This model offers flexibility for customization, as frequencies can be adjusted according to customer requirements. Whether for OEM integration, system upgrades, or specialized communication equipment, the filter provides an ideal solution to ensure stable, чистий, and interference-free signal transmission.

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Key Specifications

Standard Parameters

Пункт	Specification
Діапазон частот (Passband)	336 МГц – 344 MHz
Other Frequency Options	Customizable to customer demand
Втрата вставки	≤ 1.2 дБ
Passband Ripple	≤ 0.5 дБ
Повернення втрати	≥ 15 дБ
Out-of-Band Rejection	≥ 40 dB @ Fo ± 50 MHz
Керування потужністю	≤ 10 W
Імпеданс	50 ох
Тип роз'єму	N-KFD (ВЧ роз'єм)
Розмір модуля (mm)	89 × 20 × 32 (excluding joints)

Customizable Parameters

Пункт	Specification (337–343 MHz Band)	Specification (520–524 MHz Band)
Робоча частота	337–343 MHz	520–524 MHz
Втрата вставки	≤ 2.4 дБ	≤ 1.2 дБ
Повернення втрати	≥ 15 дБ	≥ 15 дБ
КСВ	≤ 1.3	≤ 1.3
Out-of-Band Rejection	≥ 20 dB @ 328 MHz≥ 20 dB @ 352 MHz	≥ 40 dB @ 460 MHz≥ 40 dB @ 590 MHz
Керування потужністю	10 W	10 W
Роз'єм	N-Male / N-Female	N-K / N-J
Dimensions	101 × 26 × 22 mm (including bracket)	89 × 32 × 20 mm

Helical Bandpass Filter Frequency RF Custom Frequency dimension

520-522-524Спіральний смуговий фільтр МГц

337-340-343Спіральний смуговий фільтр МГц

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Detailed Feature Breakdown

1. Frequency Selectivity

The filter has been optimized to operate in the 336–344 MHz band, providing precise bandpass characteristics. This narrowband design ensures that only signals within this range are passed, making it particularly useful in communication links that require high spectral efficiency.

2. Низькі внесені втрати

With an insertion loss of ≤1.2 dB, this filter ensures that the signal strength within the passband is preserved, minimizing degradation during transmission. This low loss makes the product suitable for sensitive receiver front ends, where every decibel of signal strength is critical.

3. Stable Passband Performance

The passband ripple of ≤0.5 dB guarantees a smooth and uniform transmission across the entire band. This reduces distortion and maintains the integrity of transmitted signals, which is vital for applications requiring high signal fidelity such as digital communication and video transmission.

4. Високий рівень відхилення за межами діапазону

The filter achieves ≥40 dB rejection at Fo ± 50 MHz, ensuring effective suppression of nearby interference sources. This level of rejection is essential in dense RF environments, preventing adjacent channel interference and enhancing overall system performance.

5. Return Loss and Impedance Matching

A return loss ≥15 dB confirms excellent impedance matching, minimizing signal reflection and maximizing power transfer. With a standard 50 Ω імпеданс, the filter integrates seamlessly with most RF systems, передавачі, і приймачі.

6. Power Handling Capability

Designed with durability in mind, the filter supports a power rating of ≤10W, making it suitable for both low and medium power RF systems. This ensures reliable performance even in transmission applications that demand higher signal strength.

7. Mechanical Design and Connectors

The filter is built in a compact housing (89 × 20 × 32 mm, за винятком роз'ємів) for easy integration into space-constrained systems. It features an N-KFD connector, known for its durability and reliable RF performance, ensuring secure connectivity.

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Додатки

The Helical Bandpass Filter (336–344MHz) finds broad applications across multiple industries:

1. Wireless Communication Systems

   • Used in base stations, repeaters, and transceivers to filter out unwanted signals.

   • Ensures clear and interference-free communication in mobile and fixed networks.

2. Military and Defense

   • Integral for secure and robust tactical communication systems.

   • Provides precise channel separation in radio communications during missions.

3. Public Safety Networks

   • Supports police, вогонь, and emergency response communication systems.

   • Guarantees reliable communication without interference, especially in crowded spectrum environments.

4. Broadcasting Equipment

   • Used in FM and VHF broadcasting stations.

   • Improves signal clarity and transmission quality for both audio and video signals.

5. Test and Measurement Systems

   • Incorporated into RF testing equipment for accurate signal analysis.

   • Filters unwanted frequencies to ensure reliable test measurements.

6. UAVs and Drone Applications

   • Helps maintain clean downlink and uplink signals for video and telemetry systems.

   • Supports COFDM-based wireless image transmission systems where stable signals are essential.

7. Industrial and Research Applications

   • Utilized in laboratory RF setups and industrial wireless monitoring systems.

   • Supports research experiments requiring precision filtering at VHF frequencies.

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Advantages of Helical Filter Design

The helical filter architecture provides several distinct advantages compared to traditional LC or cavity filters:

1. Compact Size: Despite its high performance, the filter is physically small, making it suitable for modern compact devices.

2. High Q-Factor: Helical resonators offer excellent selectivity and sharp band edges, enhancing overall filter performance.

3. Mechanical Robustness: The design ensures stable performance even under vibration or temperature fluctuations.

4. Масштабованість: Frequencies can be easily tailored to customer requirements without significant redesign.

5. Superior Rejection: Provides higher out-of-band rejection compared to many alternative filter technologies.

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Параметри налаштування

Recognizing that every application has unique frequency requirements, ми пропонуємо customizable designs. While the standard model covers the 336–344 MHz band, the filter can be tuned to other frequency bands upon request. Engineers can specify:

• Center frequency

• Пропускна здатність

• Типи конекторів (N-тип, SMA, тощо)

• Housing size constraints

This flexibility makes the filter highly adaptable across industries and project-specific needs.

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Reliability and Quality Assurance

Each Helical Bandpass Filter undergoes rigorous quality control and performance testing to ensure compliance with specifications. Parameters such as insertion loss, повернення втрат, and rejection are measured with high-precision network analyzers. The housing is manufactured from durable materials to withstand long-term use in both laboratory and field conditions.

Додатково, the product is designed to comply with international RF component standards, ensuring compatibility with global markets.

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Integration and Installation

The filter’s N-KFD connectors make installation simple and secure, allowing fast integration into existing systems. Його 50 Ω імпеданс ensures seamless compatibility with most RF transmission and reception equipment. Due to its small form factor, the filter can be installed in both portable and fixed communication setups without occupying significant space.

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Example Use Case

Consider a public safety communication network operating around 340 MHz. In such a scenario, multiple agencies share nearby frequency bands, creating the risk of interference. By incorporating this 336–344 MHz Helical Bandpass Filter into the system, engineers can ensure that only the intended signals are received while rejecting out-of-band interference. This results in improved clarity, reduced noise, and enhanced reliability for mission-critical communications.

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Висновок

The Helical Bandpass Filter (336MHz–344MHz) is a high-performance RF component that delivers precision filtering, low insertion loss, and excellent out-of-band rejection. Its compact design, customizable frequency options, and robust construction make it suitable for a wide variety of applications, from defense communication to UAV systems. By ensuring clean and stable signals, this filter significantly enhances the performance of modern wireless communication systems.

Whether deployed in broadcasting, тактичний зв'язок, or industrial monitoring, this filter provides the reliability and efficiency required in today’s demanding RF environments. With customization options available, it is a versatile solution that can be tailored to meet the unique requirements of any project.

FAQ

Питання: What frequency at edge?

Відповідь: 330-350MHz. We also offer customization options. To avoid fluctuations caused by temperature changes, the frequency range is occasionally broadened.

Question: What will be the rejection at ±12 MHz from the center frequency of the custom helical filter?

Відповідь: According to software simulation results, the rejection (suppression) at ±12 MHz offset is approximately 10 дБ до 12 дБ.

Question: What is the maximum power handling capacity of the helical filter?

Відповідь: The standard helical filter can handle up to 5 W CW (continuous wave) потужність. This rating meets the requirements of most COFDM and FPV video transmission systems.

Question: Can the helical filter support higher power levels, такі як 10 W?

Відповідь: Yes. A custom high-power version доступний за запитом. With larger housing, enhanced thermal design, or silver-plated conductors, the filter can handle up to 10 W CW.

Question: How should I choose between 5 W and 10 W versions?

Відповідь: If your transmitter output power is below 5 W, the standard model is sufficient. For transmitters with output power close to or above 5 W, we recommend choosing the 10 W custom version for safe operation and longer lifespan.

Question: Does higher power handling affect the filter’s performance?

Відповідь: No significant difference in filtering characteristics. Проте, high-power filters are slightly larger in size and may have lower insertion loss due to improved conductor quality.

Question: Can you customize the filter according to my system power and frequency?

Відповідь: Yes, обидва центральна частота and power handling можна налаштувати. Please provide your required frequency band and output power so we can design a suitable model.

Question: What is the rejection at 377 MHz and insertion loss at 340 MHz?

Відповідь: Please refer to the test results below for detailed measurement data.

Question: Loss is 2.2 db at 340 mhz right?

Відповідь: If you want to minimize insertion loss, the suppression will worsen. The filter has been designed with an additional cavity, which slightly increases the insertion loss but improves the out-of-band rejection performance.