VARIABLE GAIN PHASE SHIFTER

Abstract

The variable gain phase shifter includes an I/Q generator and a vector summing circuit. The I/Q generator generates a phase signal based on an input signal. The vector summing circuit adjusts magnitudes and directions of the first, second, third, and fourth in-phase vectors and the first, second, third, and fourth quadrature vectors based on the phase signal, the selection signal, and the current control signal, and generates an output signal by summing the in-phase vectors and the quadrature vectors. The vector summing circuit includes first, second, third and fourth vector summing units and first, second, third and fourth current control circuits. The first and second vector summing units adjust directions of the first and second in-phase vectors and the first and second quadrature vectors. The third and fourth vector summing units adjust the directions of the third and fourth in-phase vectors and the third and fourth quadrature vectors. The first and second current control circuits are connected to the first and second vector summing units, and adjust the amount of the first current and the amount of the second current. The third and fourth current control circuits are connected to the third and fourth vector summing units, and adjust the amount of the third current and the amount of the fourth current.