Interdigital Filters

Product Features

• Compact Structure: Utilizes parallelly placed, interleaved resonant rods (or microstrip lines) to achieve a compact size, saving PCB space.
• Good In-Band Flatness: Provides excellent frequency response flatness within the passband, ensuring distortion-free signal transmission.
• Strong Out-of-Band Rejection: Possesses good out-of-band attenuation characteristics, effectively filtering out unwanted frequency components.
• Frequency Customizable: Center frequency and bandwidth can be flexibly designed by adjusting the length, width, and spacing of the resonant rods.
• Relatively High Q-factor: Compared to some simpler microstrip filters, interdigital filters can achieve a higher Q-factor, leading to lower insertion loss.
• Easy to Manufacture: Can be fabricated using standard PCB or milling techniques, making them cost-effective, especially for mass production.
• Moderate Power Handling: Capable of handling medium-power RF signals, suitable for various communication applications.
• Temperature Stability: Performance remains stable within a certain temperature range.

Applications

• Wireless Communication Systems:
  • Cellular Base Stations (4G/5G): Used as bandpass filters in the RF front-end to selectively receive and transmit signals in specific frequency bands, suppressing out-of-band interference.
  • Wi-Fi & Bluetooth Devices: Utilized for channel selection and interference suppression.
  • Wireless Local Area Networks (WLAN): Ensures signal transmission within specific frequency bands.
• Radar and Electronic Warfare Systems: Performs frequency selection in receiver and transmitter links.
• Satellite Communications: Used for frequency filtering in transceivers and transponders.
• Test & Measurement Equipment: Serves as a general-purpose filter in RF test instruments for signal analysis and selection.
• Microwave Point-to-Point Communication: In microwave backhaul links, used for channel separation.
• Aerospace & Defense: Applied in airborne and military communication systems, favored for their compactness and reliability.
• GPS/GNSS Receivers: Used to filter out-of-band interference, improving positioning accuracy.