Open Access Open Access  Restricted Access Subscription or Fee Access

Broadbands Four-Branch Hybrid Coupler-Based T/R Switch for 7-Tesla Magnetic Resonance Imaging

(*) Corresponding author

Authors' affiliations



In this article, we are introducing a new broadband four-branch microstripline hybrid coupler-based switch to transmit/receive signals of a wide range of operating frequencies to/from a single or multi-tuned radio frequency coil. The proposed switch has two ranges of frequencies covering many X-atomic nuclei including: 23Na, 31P, 19F, 13C, 7Li, and 1H when they are exposed to 7 Tesla magnetic field strength in magnetic resonance imaging machines. The introduced switch does not need any type of tuning to cover the X-nuclei. The introduced switch does not exceed the realistic trace width of microstriplines that determine the allowable amount of increase in temperature when being exposed to 1 kW power and 10% duty cycles of the radio frequency pulses. Electromagnetic wave simulator (ADS) is used to characterize the S-parameters. The fundamental and third harmonic center frequencies are adjusted to resonate with two broadbands covering the speed of precession of a wide range of X-nuclei. These atomic nuclei are used as a measure to the existence of cancerous tissues, and their targeting might reduce the need for biopsy in diagnosis. The introduced switch can conduct broadband signals to/from a multi-tuned coil with low return loss values (-15 to -27 dB), low insertion loss (from -0.64 to -1.29 dB), and very good isolation, amounts to -70 dB.
Copyright © 2022 Praise Worthy Prize - All rights reserved.


Magnetic Resonance Imaging (MRI); 7 Tesla; Hybrid Coupler; X-Atomic Nuclei; Harmonic Frequency; Insertion Loss

Full Text:



P. V. S. Rao, P. Mandal, Active-terminated transmitter and receiver circuits for high-speed low-swing duobinary signaling, International Journal of Circuit Theory and Applications, vol. 40, n. 4, 2012, pp. 355-376.

A. W. Magill, H. Lei, R. Gruetter, A high-power RF switch for arterial spin labelling with a separate tagging coil, In Proceedings 20th Scientific Meeting of the International Society for Magnetic Resonance in Medicine, 2012.

D. O. Brunner, L. Furrer, M. Weiger, W. Baumberger, T. Schmid, J. Reber, B. E. Dietrich, B. J. Wilm, R. Froidevaux, K. P. Pruessmann, Symmetrically biased t/r switches for nmr and mri with microsecond dead time, Journal of Magnetic Resonance, vol. 263, 2016, pp. 147-155.

M. Twieg, M. Rooij, M. Griswold, Enhancement mode gan on silicon (egan fets) for coil detuning, In Proc. Int. Soc. Magn. Reson. Med., 2014.

P. Grannell, M. Orchard, P. Mansfield, A. Garroway, D. Stalker, A fet analogue switch for pulsed NMR receivers, Journal of Physics E: Scientific Instruments, vol. 6, n. 12, 1973.

H. Raki, K. T. V. Koon, I. Saniour, H. Souchay, S. A. Lambert, F. Robb, O. Beuf, Serial and parallel active decoupling characterization using RF MEMs switches for receiver endoluminal coils at 1.5 T, IEEE Sensors Journal, vol. 20, n. 18, 2020, pp. 10511-10520.

D. O. Brunner, N. De Zanche, J. Froehlich, D. Baumann, K. Pruessmann, A symmetrically fed microstrip coil array for 7T, In 15th Proc. Intl. Soc. MRM, 2007.

S. Orzada, A. Bahr, T. Bolz, A novel 7 T microstrip element using meanders to enhance decoupling, In 16th Proc. Intl. Soc. MRM, 2008.

G. Saleh, F. Sibaii, N. Alashban, H. Alkhateeb, F. Hegazi, M. Hegazi, Effects of tissues and geometric shapes of phantoms on the specific energy absorption rate, International Journal of RF and Microwave Computer-Aided Engineering, vol. 28, n. 3, 2018.

G. Saleh, K. Solbach, A. Rennings, and Z. Chen, SAR reduction for dipole RF coil element at 7 Tesla by using dielectric overlay, in 2012 Loughborough Antennas & Propagation Conference (LAPC). 2012.

G. Saleh, K. Solbach, D. Erni, A. Rennings, Soft Surface - EBG Structure to Improve the |H|/|E| Field Ratio of Stripline Coil for 7 Tesla MRI, Proc. Intl. Soc. Mag. Reson. Med. 21 (ISMRM), 2013.

G. Saleh. High Impedance Surface-Electromagnetic Band Gap (HIS-EBG) Structures for Magnetic Resonance Imaging (MRI) Applications. PhD Thesis. Universität Duisburg-Essen; 2013.

Abuelhaija, A., Salama, S., El-Absi, M., Multi-Tuned Radiofrequency Coil Using Microfluidically Tunable Capacitor for Magnetic Resonance Imaging/Spectroscopy at 7-Tesla, (2019) International Journal on Communications Antenna and Propagation (IRECAP), 9 (6), pp. 419-427.

M. Abou-Khousa, A. Mustapha, Wideband RF Transmit-Receive Switch for Multi-Nuclei NMR Spectrometers. IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 69, n. 3, 2021.

R. H. Caverly, PIN Diode Switching Speed for MRI Applications, IEEE MTT-S International Microwave Biomedical Conference (IMBioC), 2020.

A. Nandawadekar et al., Thermal and Electrical Behaviour of the Persistent Current Switch for a Whole-Body Superconducting MRI Magnet, IEEE Transactions on Applied Superconductivity, vol. 31, n. 5, 2021.

C. Li et al., Persistent current switch for HTS superconducting magnets: Design control strategy and test results, IEEE Trans. Appl. Supercond., vol. 29, n. 2, 2019.

B. Thapa, J. Kaggie, N. Sapkota, D. Frank, and E.-K. Jeong, Design and development of a general-purpose transmit/receive (T/R) switch for 3T MRI, compatible for a linear, quadrature and double-tuned rf coil Concepts in Magnetic Resonance Part B: Magnetic Resonance Engineering, vol. 46, n. 2, 2016, pp. 56-65.

G. Saleh, A. Abuelhaija, Dual tuned switch for dual resonance 1H/13C MRI coil, In 2021 IEEE International IOT, Electronics and Mechatronics Conference (IEMTRONICS), 2021.

A. Abuelhaija, G. Saleh, "Dual tuned 1H/31P quadrature microstripline-based transmit/receive switch for 7 Tesla magnetic resonance imaging. International Journal of Electrical & Computer Engineering, vol. 12, n. 3, 2022.

A. Abuelhaija, G. Saleh, O. Nashwan, S. Issa, and S. Salama, Multi-and dual-tuned microstripline-based transmit/receive switch for 7-Tesla magnetic resonance imaging, International Journal of Imaging Systems and Technology, 2021.

A. Maunder, M. Rao, F. Robb, J. M. Wild, Comparison of mems switches and pin diodes for switched dual tuned RF coils, Magnetic resonance in medicine, vol. 80, n. 4, 2018, pp. 1746-1753.

A. Abuelhaija, G. Saleh, T. Baldawi, S. Salama, Symmetrical and asymmetrical microstripline-based transmit/receive switches for 7-Tesla magnetic resonance imaging, International Journal of Circuit Theory and Applications, vol. 49, n. 7, 2021, pp. 2082-2093.

S. Orzada, K. Solbach, M. Gratz, S. Brunheim, T. M. Fiedler, S. Johst, A. K. Bitz, S. Shooshtary, A. Abuelhaija, M. N. Voelker et al., A 32-channel parallel transmit system add-on for 7T MRI, Plos one, vol. 14, n. 9, 2019.

Abuelhaija, A., Saleh, G., Salama, S., Issa, S., T- and Cascaded Pi-Shaped 1H T/R Switches with Realistic Trace Width for 7 Tesla MRI, (2022) International Journal on Communications Antenna and Propagation (IRECAP), 12 (1), pp. 39-46.

A. Abuelhaija, G. Saleh, Transmit/receive switch based on microstripline coupler, U.S. Patent No. 11,493,578. 8 Nov. 2022.

M. Muraguchi, T. Yukitake, Y. Naito, Optimum design of 3-db branch-line couplers using microstrip lines, IEEE transactions on Microwave Theory and Techniques, vol. 31, n. 8, 1983, pp. 674-678.

RH. Caverly, PIN diode-based transmit-receive switch for 7 T MRI, IEEE Topical Conference on Biomedical Wireless Technologies, Networks, and Sensing Systems (BioWireleSS); 2016.

X. Yan, Z. Cao, WA. Grissom, Ratio-adjustable power splitters for array-compressed parallel transmission, Magn Reson Med., vol. 79, n. 4, 2018, pp. 2422-2431.


  • There are currently no refbacks.

Please send any question about this web site to
Copyright © 2005-2024 Praise Worthy Prize