Patent ID: 7015773

Claim:
A phase shifter circuit for imparting a phase shift to an input signal applied at an input port such that a phase shifted signal appears at an output port, the circuit comprising: an input port coupled to receive the input signal; an output port coupled to provide the phase shifted output signal, the output port coupled to the input port by coupled lines, such coupling between the input port and output port having a characteristic input/output impedance; a first quadrature port and a second quadrature port, the first and second quadrature ports coupled to one another, such coupling between quadrature ports having a characteristic quadrature port impedance, being different from the input/output port impedance; a first impedance transformer coupled between the input port and a first one of the quadrature ports, the first impedance transformer transforming the characteristic input/output impedance across the input/output ports to the characteristic quadrature port impedance across the quadrature ports; and a second impedance transformer coupled between a second one of the quadrature ports and the output port, the second impedance transformer transforming the characteristic quadrature port impedance across the quadrature ports to the characteristic input/output impedance.