Air-bridged Schottky diodes for dynamically tunable millimeter-wave metamaterial phase shifters

Evangelos Vassos, James Churm, Jeff Powell, Colin Viegas, Byron Alderman, Alexandros Feresidis

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


A low loss metamaterial unit cell is presented with an integrated GaAs air-bridged Schottky diode to produce a dynamically tunable reflective phase shifter that is capable of up to 250° phase shift with an experimentally measured average loss of 6.2 dB at V-band. The air-bridged Schottky diode provides a tuneable capacitance in the range between 30 and 50 fF under an applied reverse voltage bias. This can be used to alter the resonant frequency and phase response of a split patch unit cell of a periodic metasurface. The air-bridged diode die, which is flip-chip soldered to the patch, has ultra-low parasitic capacitance and resistance. Simulated and measured results are presented which verify the potential for the attainment of diode switching speeds with acceptable losses at mmWave frequencies. Furthermore the study shows that this diode-based unit cell can be integrated into metamaterial components, which have potential applications in future mmWave antenna beam-steering, intelligent reflecting surfaces for 6G communications, reflect-arrays, transmit-arrays or holographic antennas.

Original languageEnglish
Article number5988
Number of pages10
JournalScientific Reports
Issue number1
Early online date16 Mar 2021
Publication statusPublished - 1 Dec 2021
Externally publishedYes

Cite this