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US 8,942,621 B2Granted
Phase adjustment circuit and phase adjustment method
AssigneeAsahi Kasei Microdevices Corporation
InventorTakeji Fujibayashi
Life of this patent
Estimating the term…
Abstract
There is provided a circuit for adjusting phases of IQ local signals. As to a local signal A and a local signal B generated by a local signal generating unit for the purpose of generating IQ quadrature local signals, the local signal B in which the gain is adjusted is added to the output of the local signal A to obtain the local signal A2, and the local signal A in which the gain is adjusted is subtracted from the output of the local signal B to obtain the local signal B2. Even if the phase relationship between the local signal A and the local signal B deviates from 90 degrees, the phase difference between the local signal A2 and the local signal B2 can be adjusted with ease by changing the adjustment amounts of variable amplifiers AMP1 and AMP2.
Claims13
A phase adjustment circuit comprising:
- a first amplifier configured to receive one of a first I local signal and a first Q local signal having a frequency identical to that of the first I local signal and a phase different from that of the first I local signal, the first amplifier having a first gain to provide a desired phase difference between the first I local signal and the first Q local signal;
- a first adding and subtracting unit for configured to change between adding and subtracting the other of the first I local signal and the first Q local signal to or from an output signal from the first amplifier, and to output a second Q local signal when said one of the first I local signal and the first Q local signal is the first I local signal, and to output a second I local signal when said one of the first I local signal and the first Q local signal is the first Q local signal;
- a second amplifier configured to receive the other of the first I local signal and the first Q local signal, the second amplifier having a second gain to provide the desired phase difference between the first I local signal and the first Q local signal;
- and
- a second adding and subtracting unit configured to change between adding and subtracting said one of the first I local signal and the first Q local signal to or from an output signal from the second amplifier, and to output a second I local signal when said one of the first I local signal and the first Q local signal is the first I local signal, and to output a second Q local signal when said one of the first I local signal and the first Q local signal is the first Q local signal,
- wherein the second I local signal and the second Q local signal is input to a quadrature mixer.
3 more elements
A phase adjustment circuit, comprising:
- a first amplifier configured to receive one of a first I local signal and a first Q local signal having a frequency identical to that of the first I local signal and a phase different from that of the first I local signal, the first amplifier having a first gain to provide a desired phase difference between the first I local signal and the first Q local signal;
- a first adding and subtracting unit configured to add or subtract the other of the first I local signal and the first Q local signal to or from an output signal from the first amplifier, and to output a second Q local signal when said one of the first I local signal and the first Q local signal is the first I local signal, and to output a second I local signal when said one of the first I local signal and the first Q local signal is the first Q local signal;
- a second amplifier configured to receive the other of the first I local signal and the first Q local signal, the second amplifier having a second gain to provide the desired phase difference between the first I local signal and the first Q local signal;
- and
- a second adding and subtracting unit configured to add or subtract said one of the first I local signal and the first Q local signal to or from an output signal from the second amplifier, and to output a second I local signal when said one of the first I local signal and the first Q local signal is the first I local signal, and to output a second Q local signal when said one of the first I local signal and the first Q local signal is the first Q local signal,
- wherein the second I local signal and the second Q local signal is input to a quadrature mixer, and
- wherein one of the first adding and subtracting unit and the second adding and subtracting unit makes an addition, and the other of them makes a subtraction.
4 more elements
A phase modulation method comprising:
- a first step for amplifying one of a first I local signal and a first Q local signal having a frequency identical to that of the first I local signal and a phase different from that of the first I local signal, with a first gain to provide a desired phase difference between the first I local signal and the first Q local signal;
- a second step for changing between adding and subtracting the other of the first I local signal and the first Q local signal to or from an output signal from the first amplifier, outputting a second Q local signal when said one of the first I local signal and the first Q local signal is the first I local signal, and outputting a second I local signal when said one of the first I local signal and the first Q local signal is the first Q local signal;
- a third step for amplifying the other of the first I local signal and the first Q local signal, with a second gain to provide a desired phase difference between the first I local signal and the first Q local signal;
- and
- a fourth step for changing between adding and subtracting said one of the first I local signal and the first Q local signal to or from an output signal from the second amplifier, outputting a second I local signal when said one of the first I local signal and the first Q local signal is the first I local signal, and outputting a second Q local signal when said one of the first I local signal and the first Q local signal is the first Q local signal,
- wherein the second I local signal and the second Q local signal is input to a quadrature mixer.
3 more elements
A phase modulation method comprising:
- a first step for amplifying one of a first I local signal and a first Q local signal having a frequency identical to that of the first I local signal and a phase different from that of the first I local signal, with a first gain to provide a desired phase difference between the first I local signal and the first Q local signal;
- a second step for adding or subtracting the other of the first I local signal and the first Q local signal to or from an output signal from the first amplifier, outputting a second Q local signal when said one of the first I local signal and the first Q local signal is the first I local signal, and outputting a second I local signal when said one of the first I local signal and the first Q local signal is the first Q local signal;
- a third step for amplifying the other of the first I local signal and the first Q local signal, with a second gain to provide a desired phase difference between the first I local signal and the first Q local signal;
- and
- a fourth step for adding or subtracting said one of the first I local signal and the first Q local signal to or from an output signal from the second amplifier, outputting a second I local signal when said one of the first I local signal and the first Q local signal is the first I local signal, and outputting a second Q local signal when said one of the first I local signal and the first Q local signal is the first Q local signal,
- wherein the second I local signal and the second Q local signal is input to a quadrature mixer, and
- one of the second step and the fourth step makes an addition, and the other of the second step and the fourth step makes a subtraction.
4 more elements
Dependencies are inferred from the claim text.