An innovative method based on Huygens sources to regulate the direction that power flows in microwave transmission line systems is developed and confirmed with measurements. The phase difference between the electric and magnetic currents in the Huygens source is utilized to finely control the ratio of the wave propagation amplitudes and, hence, power flows along the transmission line in opposite directions. The operating principles are elucidated with both the field distributions in a rectangular waveguide as the transmission line system and the voltages and currents in a transmission line circuit model driven by Huygens sources. The transmission line circuit models excited with electric and magnetic current sources separately and with their balanced combination provide a precise means to quantitatively demonstrate the tunability of the power flow with the Huygens source. A proof-of-concept experiment was implemented in a microwave rectangular waveguide to validate the theoretical analysis. The measured results, in good agreement with their simulated values, demonstrate that the reported approach leads to a wideband operation and large dynamic directional power ratios that are advantageous in the design of multifunctional electromagnetic devices and systems.
- Directional power flow
- Huygens source
- transmission lines
ASJC Scopus subject areas
- Electrical and Electronic Engineering