A Balanced Substrate Integrated Waveguide Phase Shifter with Wideband Common-Mode Suppression

Area of Science:

• Electrical Engineering
• Electromagnetics
• Microwave Engineering

Background:

• Substrate Integrated Waveguides (SIW) are essential components in modern microwave circuits.
• Developing balanced phase shifters with effective common-mode (CM) suppression is crucial for signal integrity.
• Existing designs often face limitations in bandwidth and phase shift range for CM suppression.

Purpose of the Study:

• To propose and validate a novel slotted substrate integrated waveguide (SIW) based balanced phase shifter.
• To achieve wideband common-mode (CM) suppression and a wide phase shift range.
• To demonstrate a simple and manufacturable structure with high performance.

Main Methods:

• Utilizing the mode selectivity of TE20 and TE10/TE30 modes within the SIW for differential-mode (DM) signal transmission and CM suppression.
• Incorporating slots to enhance the bandwidth of CM suppression.
• Employing a phase slope counteraction between slots and delay lines to achieve wideband phase shift with low deviation.

Main Results:

• The proposed SIW phase shifter demonstrates wideband CM suppression with a relative bandwidth of up to 59%.
• Achieved wide phase shift ranges (45°, 90°, 135°, 180°) with a relative operating bandwidth of 20% for each.
• Exhibited low insertion loss (minimum 0.41 dB) and high return loss (greater than 15 dB).

Conclusions:

• The developed slotted SIW phase shifter offers significant advantages in wideband CM suppression and phase shift capability.
• The design presents a simple, easily fabricated structure suitable for various RF applications.
• The performance metrics surpass those of current state-of-the-art phase shifters.