Wideband (7–24 GHz) Quadrature All-Pass Filter (QAF) 

This project focuses on the design and analysis of a wideband quadrature all-pass filter (QAF) for phased array and phase shifter applications. The goal was to achieve accurate quadrature phase response over a wide frequency range while maintaining low gain and phase error for high-frequency wireless systems. 

Objectives

• Design a wideband QAF operating from 7 to 24 GHz.

• Achieve accurate I/Q phase balance across the bandwidth.

• Minimize gain error and phase error for phase shifter applications.

Outcomes & Contributions

• Designed and analyzed a wideband QAF with gain error ≤ ±0.9 dB and phase error ≤ 5.6° across the full bandwidth.

• Studied the impact of each circuit component on bandwidth, voltage gain, and phase shift.

• Demonstrated that the proposed QAF enables implementation of a 6-bit phase shifter.

• Awarded 1st Place in the KAUST SSI 2025 E-Poster Competition for excellence in project quality, technical presentation, and poster design.
  
  

Technical Details & Skills

• Field: RF & Microwave Circuit Design

• Tools: ADS (Advanced Design System)

• Techniques: All-pass filter design, phase error analysis, gain balancing

• Applications: Phased array antennas, radar systems, 5G and wireless communication