Reconfigurable Antennas and RF Components at Millimeter Wave
Reconfigurability is a vital feature of future agile millimeter wave systems for sensing, imaging, wireless, and satellite communications. Reconfigurable antennas are an integral part of such systems as they can control polarization, frequency, radiation pattern, or characteristic impedance.
Paraffin-Based Reconfigurable Components at Millimeter Wave
The main goal of this project is to design low-loss millimeter wave (mmW) RF components using novel materials such as paraffin. Alkane or paraffin is an organic phase change material (PCM) that exhibits low a dielectric loss, (tanδ=6.6E-4 at 110 GHz), with a relative dielectric constant of 2.26. Paraffin is also a mechanical PCM that undergoes a 15% volumetric change through its solid-liquid phase change.
Due to its unique electrical and mechanical properties, paraffin PCM variable capacitors are very attractive for designing reconfigurable antennas and distributed loaded line phase shifters at mmW band.
In our group, we have developed a continuously reconfigurable antenna at 100 GHz by monolithically integrating the paraffin PCM capacitors with a slot antenna. Designed antenna has a reconfiguration range of 96–102.2 GHz with a maximum gain of 3 dBi. (Figures 1—2)
In addition, we have also developed a distributed loaded line phase shifter based on a new class of electro-thermally actuated RF MEMS devices using paraffin PCM. Designed phase shifter has a figure-of merit of 71.8°/dB achieved while maintaining a return loss more than 12 dB.Designed phase shifter has a maximum insertion loss of 5 dB for a 360° of phase shift. (Figure 3)
© Prof. Nima Ghalichechian's Group
B. Ghassemiparvin and N. Ghalichechian, “Reconfigurable Millimeter-wave Antennas using Paraffin Phase Change Materials,” European Conference on Antennas and Propagation (EuCAP), Davos, Switzerland, 10-15 Apr, 2016. DOI:https://doi.org/10.1109/EuCAP.2016.7481595 (Download PDF)
B. Ghassemiparvin and N. Ghalichechian, “Novel Paraffin-Based 100-GHz Variable Capacitors for Reconfigurable Antennas," European Conference on Antennas and Propogation (EuCAP), Paris, France, 19-24 Mar, 2017. DOI:https://doi.org/10.23919/EuCAP.2017.7928379 (Download PDF)
B. Ghassemiparvin and N. Ghalichechian, "W-Band True-Time Delay Phase Shifters Using Paraffin Microactuators," European Conference on Antennas and Propogation (EuCAP), London, UK, 9-13 Apr, 2018.