Reconfigurable ring filter with controllable frequency response.

Area of Science:

• Electrical Engineering
• Microwave Engineering
• Filter Design

Background:

• Reconfigurable filters are crucial for modern wireless communication systems.
• Traditional filters often lack tunability and compactness.
• Single-side-access ring topology offers a unique platform for filter reconfigurability.

Purpose of the Study:

• To introduce a novel reconfigurable ring filter based on single-side-access ring topology.
• To develop a synthesis method for determining capacitive tuning elements.
• To demonstrate the filter's performance using both lumped capacitors and varactor diodes.

Main Methods:

• Utilized capacitive tuning elements to manipulate the electrical length of the ring filter.
• Developed a synthesis approach to calculate capacitive element values.
• Fabricated and measured two microstrip prototypes: one with lumped capacitors and another with varactor diodes.

Main Results:

• The lumped element filter reconfigured from 2 GHz to 984.4 MHz, achieving 71% miniaturization.
• The varactor diode filter tuned across a 280 MHz range from 1.10 GHz to 1.38 GHz.
• Both prototypes exhibited compact size, acceptable insertion loss, and high selectivity.

Conclusions:

• The proposed single-side-access reconfigurable ring filter is effective for frequency tuning and miniaturization.
• The developed synthesis method provides a viable approach for designing such reconfigurable filters.
• The use of lumped elements and varactor diodes offers flexibility in achieving desired reconfigurability and performance.