Diode SPDT Switching at High Power with Octave Microwave Bandwidth

High peak and high average radiofrequency power transmit/receive switch for thermal magnetic resonance

“…It consists of nonmagnetic components, allowing it to be placed inside the scanner bore in close proximity to the RF antenna. The strategic placement of the λ/4 stubs routes the RF signal from the transmitter directly to the RF coil/antenna without directly passing through any lossy electronic components such as PIN diodes . This enables the use of high average powers in comparison to other Tx/Rx switches designed for MRI applications .…”

“…Using microstrips instead of semirigid cables could be another approach to reduce the current size of the high‐power Tx/Rx switch, which could increase transmission losses of the circuit …”

“…The strategic placement of the k/4 stubs routes the RF signal from the transmitter directly to the RF coil/antenna without directly passing through any lossy electronic components such as PIN diodes. 27 This enables the use of high average powers in comparison to other Tx/Rx switches designed for MRI applications. [22][23][24] For instance, the conventional Tx/Rx design that was used as a reference in this study uses PIN diodes in the transmission path that exhibit a series resistance of 0.35 X and 2 pF.…”

“…The electrical circuit of the proposed high‐power Tx/Rx switch for 7 T ( f = 297 MHz) is shown in Figure A with a photograph of the assembled switch shown in Figure B. In the proposed single‐pole double‐through design, no electronic components are placed in the direct transmission path (Figure C) . Consequently, excessive heat accumulation during high duty cycle high‐power RF pulse transmission is avoided and higher peak and average powers can be applied.…”

“…In the proposed single-pole double-through design, no electronic components are placed in the direct transmission path ( Figure 1C). 27 Consequently, excessive heat accumulation during high duty cycle high-power RF pulse transmission is avoided and higher peak and average powers can be applied.…”