Quadrature transmit array design using single-feed circularly polarized patch antenna for parallel transmission in MR...

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Radiofrequency (RF) Engineering
• Antenna Design

Background:

• Quadrature coils enhance MRI sensitivity and reduce excitation power.
• Existing quadrature coil designs can be complex and bulky.
• Parallel transmission at ultrahigh fields requires advanced coil technology.

Purpose of the Study:

• To propose a novel quadrature array design strategy for parallel transmission at 298 MHz.
• To utilize a single-feed circularly polarized (CP) patch antenna technique for simplified coil construction.
• To demonstrate the feasibility of this design for ultrahigh field (7 Tesla) MRI.

Main Methods:

• Designed a quadrature array using nearly square ring microstrip antennas with diagonal single-feed points.
• Employed numerical simulations to assess element decoupling and RF field homogeneity.
• Utilized Bloch equation simulations to model the excitation process for parallel transmission.

Main Results:

• Achieved excellent element decoupling (better than -35 dB).
• Demonstrated homogeneous RF fields with deep penetration and quadrature behavior.
• Validated the design's feasibility for parallel transmission at 7 Tesla via Bloch simulations.

Conclusions:

• The single-feed CP patch antenna technique offers a practical and compact approach to quadrature coil array design.
• This novel design is suitable for parallel transmission applications at ultrahigh magnetic fields.
• The proposed method can improve MR performance and simplify coil construction.