Electronically switchable band tuned filtering power divider for Sub-6 GHz applications

Area of Science:

• Electrical Engineering
• Radio Frequency (RF) Engineering
• Microwave Engineering

Background:

• Conventional multi-band receivers face challenges with increased loss, complexity, and footprint due to separate narrowband and wideband chains.
• Adaptive and spectrum-flexible RF hardware is crucial for evolving Sub-6 GHz wireless front ends.
• Miniaturization and electronic tunability are key requirements for modern wireless communication systems.

Purpose of the Study:

• To develop a compact, electronically switchable filtering power divider (FPD) for Sub-6 GHz wireless applications.
• To integrate a bandpass filter with a power divider core for adaptive frequency selection.
• To achieve size reduction and electronic switching capabilities for enhanced RF hardware.

Main Methods:

• Integration of a folded-resonator bandpass filter with a Wilkinson-based power divider core.
• Utilizing inverted S-shaped and modified C-shaped resonator elements for miniaturization.
• Employing four PIN diodes in a step-impedance resonating structure for electronic switching between wideband and narrowband modes.

Main Results:

• Wideband operation (2.9 GHz center, 34.4% bandwidth) with 1.4 dB insertion loss and >10 dB isolation in diode-OFF state.
• Narrowband operation (2.35 GHz center) with >20 dB return loss and >10 dB isolation in diode-ON state.
• Achieved miniaturization with an electrical size of 0.14λ₀ × 0.18λ₀.

Conclusions:

• The proposed filtering power divider offers electronically tunable wideband and narrowband responses.
• The design achieves miniaturization, equal power division, high isolation, and electronic selectivity.
• This FPD is suitable for adaptive and spectrum-flexible RF hardware in Sub-6 GHz wireless front ends.