TY - GEN
T1 - Liquid crystal based phase shifters in 60 GHz band
AU - Bulja, S.
AU - Mirshekar-Syahkal, D.
AU - Yazdanpanahi, M.
AU - James, R.
AU - Day, S. E.
AU - Fernández, F. A.
PY - 2010
Y1 - 2010
N2 - Preliminary structures and performance results of two different 60 GHz band planar phase shifters using liquid crystal (LC) are presented. The first phase shifter is based on a meandered microstrip line structure with the conductor pattern exposed to a layer of a nematic LC, while the second phase shifter is based on the reflection type microstrip line phase shifter structure whose tunable reflective loads are formed on a nematic LC substrate. The LC used in these two phase shifters is E7 with a low temperature coefficient over a wide range of temperatures. In both phase shifters, the LC is biased through a variable low voltage external source allowing for the control of the dielectric constant of the LC. To facilitate the on-wafer measurement and the application of the electric field to the LC, a broadband transition from the microstrip line to the CPW is developed and used in both phase shifters. The best figure of merit of the meandered line phase shifter, 20.8°/dB , occurs at 60.7 GHz coinciding with a differential phase shift of 243 degrees, while the RTPS achieves a maximum figure of merit, 12.3°/dB , at 61.31 GHz corresponding to a differential phase shift of 170 degrees.
AB - Preliminary structures and performance results of two different 60 GHz band planar phase shifters using liquid crystal (LC) are presented. The first phase shifter is based on a meandered microstrip line structure with the conductor pattern exposed to a layer of a nematic LC, while the second phase shifter is based on the reflection type microstrip line phase shifter structure whose tunable reflective loads are formed on a nematic LC substrate. The LC used in these two phase shifters is E7 with a low temperature coefficient over a wide range of temperatures. In both phase shifters, the LC is biased through a variable low voltage external source allowing for the control of the dielectric constant of the LC. To facilitate the on-wafer measurement and the application of the electric field to the LC, a broadband transition from the microstrip line to the CPW is developed and used in both phase shifters. The best figure of merit of the meandered line phase shifter, 20.8°/dB , occurs at 60.7 GHz coinciding with a differential phase shift of 243 degrees, while the RTPS achieves a maximum figure of merit, 12.3°/dB , at 61.31 GHz corresponding to a differential phase shift of 170 degrees.
KW - Dielectric anisotropy
KW - Liquid crystal (LC)
KW - Meandered inverted microstrip line phase shifter
KW - Reflection type phase shifter (RTPS)
UR - https://www.scopus.com/pages/publications/78649920388
M3 - Conference proceeding
AN - SCOPUS:78649920388
SN - 9782874870187
T3 - European Microwave Week 2010, EuMW2010: Connecting the World, Conference Proceedings - European Wireless Technology Conference, EuWiT 2010
SP - 37
EP - 40
BT - European Microwave Week 2010, EuMW2010
T2 - 13th European Microwave Week 2010, EuMW2010: Connecting the World - 3rd European Wireless Technology Conference, EuWiT 2010
Y2 - 27 September 2010 through 28 September 2010
ER -