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 for receiving 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;
- and
- a first adding and subtracting unit 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 phase modulation method comprising:
- a first step for receiving 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;
- and
- 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.
Dependencies are inferred from the claim text.