Phase shifter

摘要

A phase shifter comprises a signal input, a signal output, a signal path between the signal input and the signal output, and a plurality of sections. Each section of the plurality of sections comprises a signal line portion and an associated material portion having a characteristic that is tuneable to apply an adjustable phase shift to a signal transmitted over the signal line portion, wherein the characteristic of the material of each section is tuneable individually, wherein the signal line portions are connected in series in the signal path or wherein the phase shifter is configured to switch the signal line portions in series in the signal path.