Abstract: A method for suppressing harmonic signals includes: mixing a first local oscillation signal with an input signal to obtain a first output signal, and mixing a second local oscillation signal with the input signal to obtain a second output signal, the first output signal including an n-order harmonic signal, n being a positive integer greater than 1; and adding the first output signal and the second output signal to suppress the n-order harmonic signal in the first output signal. The first local oscillation signal and the second local oscillation signal have different mark-space ratios but a same oscillation frequency.

Abstract: A searching method for finding a target location in a variable space is provided. The variable space is constructed by a set of variables and has multiple sub-spaces. The target location renders an output result of a wireless communication system to satisfy a target value. The search method includes steps of: providing the set of variables; identifying a target sub-space where the target location is located from the sub-spaces; obtaining a plurality of gradients of the output result at a predetermined location from the target sub-space, each of the gradients corresponding to a direction of change; and selecting one from the directions of change according to the gradients, and changing values of the set of variables according to the selected direction of change to find the target location.

Abstract: A method for suppressing harmonic signals includes: mixing a first local oscillation signal with an input signal to obtain a first output signal, and mixing a second local oscillation signal with the input signal to obtain a second output signal, the first output signal including an n-order harmonic signal, n being a positive integer greater than 1; and adding the first output signal and the second output signal to suppress the n-order harmonic signal in the first output signal. The first local oscillation signal and the second local oscillation signal have different mark-space ratios but a same oscillation frequency.

Abstract: An operation amplifier (op amp) having a bias current detection circuit that monitors the bias current flowing in an output stage of the op amp. When the bias current detection circuit detects that too much current is being wasted, e.g., sunk to ground, then the amount of bias current is reduced. Similarly, when the bias current detection circuit detects that insufficient bias current is being supplied to the output stage of the op amp, the amount of bias current is increased. In one implementation, the output of the bias current detection circuit may be signals indicative of, respectively, too much bias current and too little bias current, wherein those outputs are supplied to a state machine which is configured to control the amount of bias current being supplied in a stepwise fashion.

Abstract: An operation amplifier (op amp) having a bias current detection circuit that monitors the bias current flowing in an output stage of the op amp. When the bias current detection circuit detects that too much current is being wasted, e.g., sunk to ground, then the amount of bias current is reduced. Similarly, when the bias current detection circuit detects that insufficient bias current is being supplied to the output stage of the op amp, the amount of bias current is increased. In one implementation, the output of the bias current detection circuit may be signals indicative of, respectively, too much bias current and too little bias current, wherein those outputs are supplied to a state machine which is configured to control the amount of bias current being supplied in a stepwise fashion.

Abstract: A searching method for finding a target location in a variable space is provided. The variable space is constructed by a set of variables and has multiple sub-spaces. The target location renders an output result of a wireless communication system to satisfy a target value. The search method includes steps of: providing the set of variables; identifying a target sub-space where the target location is located from the sub-spaces; obtaining a plurality of gradients of the output result at a predetermined location from the target sub-space, each of the gradients corresponding to a direction of change; and selecting one from the directions of change according to the gradients, and changing values of the set of variables according to the selected direction of change to find the target location.