Patent ID: 7282979
Filing Date: 2007-10-16
Classification: H03H,H03K,H03L

Abstract:
1. A phase shifting device comprising: a signal source; a first variable phase shifter in which an amount of phase shift rotation can be changed by a first phase shift control signal; first and second N multiplying circuits (N is an integer greater than or equal to 2); and a phase comparator, wherein an output from the signal source is connected to an input of the first variable phase shifter and to an input of the second N multiplying circuit, an output from the first variable phase shifter is connected to an input of the first N multiplying circuit, an output from the first N multiplying circuit serves as a first output signal, and an output from the second N multiplying circuit serves as a second output signal, and the first output signal and the second output signal are inputted to the phase comparator, and an output from the phase comparator is fed back, as the first phase shift control signal, to the first variable phase shifter, whereby the amount of phase shift rotation of the first variable phase shifter is controlled such that a phase shift between the first output signal and the second output signal is constant, said phase shifting device further comprising: a first gain limiting circuit having an input to which the first output signal is connected; and a second gain limiting circuit having an input to which the second output signal is connected, wherein an output from the first gain limiting circuit serves as a third output signal, and an output from the second gain limiting circuit serves as a fourth output signal.