Phase modulation apparatus and wireless communication apparatus
First Claim
1. A two-point modulation type phase modulation apparatus for modulating a carrier frequency signal using an inputted digital baseband modulation signal by setting a frequency dividing ratio of a frequency divider of a PLL circuit based on the inputted digital baseband modulation signal, and adding a voltage corresponding to an analog-converted signal to the inputted digital baseband signal for supply to a control voltage terminal of a voltage controlled oscillator of the PLL circuit, comprising:
- a D/A converter that converts the inputted digital baseband signal to an analog signal;
an adding section that adds an output signal of the D/A converter and an output of a loop filter of the PLL circuit, and outputs the addition signal to the control voltage terminal of the voltage controlled oscillator; and
a peak control section provided at a front stage of the D/A converter, that carries out smoothing of peak portions appearing in the inputted digital baseband signal.
2 Assignments
0 Petitions
Accused Products
Abstract
A two-point modulation type phase apparatus and a wireless communication apparatus capable of achieving a reduction in circuit scale and low power consumption while maintaining modulation precision. It is possible to provide a D/A converter (150) that converts the inputted digital baseband signal to an analog signal, an adder (110) that adds an output signal of a D/A converter (150) and an output of a loop filter (135) to output to a control voltage terminal of the voltage controlled oscillator (105), and a peak control section (140) provided at a front stage of the D/A converter (150) that carries out smoothing of peak portions appearing at the inputted digital baseband signal, at a two-point modulation type phase modulation apparatus (100) that modulates a-carrier frequency signal using an inputted digital baseband signal by setting a frequency dividing ratio of a frequency divider (115) of a PLL circuit based on an inputted digital baseband modulation signal, and adding a voltage corresponding to a signal that is an inputted digital baseband signal analog-converted for supply to a control voltage terminal of a voltage controlled oscillator (105).
34 Citations
11 Claims
-
1. A two-point modulation type phase modulation apparatus for modulating a carrier frequency signal using an inputted digital baseband modulation signal by setting a frequency dividing ratio of a frequency divider of a PLL circuit based on the inputted digital baseband modulation signal, and adding a voltage corresponding to an analog-converted signal to the inputted digital baseband signal for supply to a control voltage terminal of a voltage controlled oscillator of the PLL circuit, comprising:
-
a D/A converter that converts the inputted digital baseband signal to an analog signal;
an adding section that adds an output signal of the D/A converter and an output of a loop filter of the PLL circuit, and outputs the addition signal to the control voltage terminal of the voltage controlled oscillator; and
a peak control section provided at a front stage of the D/A converter, that carries out smoothing of peak portions appearing in the inputted digital baseband signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification