Phase shifter and antenna device

Abstract

A phase shifter that includes a 90-degree hybrid circuit and a variable-length stub group including two variable-length stubs connected to the 90-degree hybrid circuit. The variable-length stub includes a first switch connected to the 90-degree hybrid circuit and including vanadium dioxide of a first composition that phase-transitions between an insulation phase and a metal phase in a first phase transition temperature range, a first stub connected to the first switch, a second switch connected to the first stub and including vanadium dioxide of a second composition that phase-transitions between an insulation phase and a metal phase in a second phase transition temperature range higher than the first phase transition temperature range, and a second stub connected to the second switch and having an end grounded.

Dependencies are inferred from the claim text.