Patent ID: 9025706
Filing Date: 2015-05-05
Classification: H03F,H03G,H04B,H04L

Abstract:
1. A reception circuit comprising: a mixer configured to frequency-convert a wideband high-frequency reception signal and output a baseband reception signal; at least one VGA configured to amplify the baseband reception signal using a prescribed gain; at least one HPF configured to stop part, in a band that is lower than a first cutoff frequency, of the amplified reception signal; an ADC configured to AD-convert an output signal of the at least one HPF and output a digital reception signal; a processor configured to demodulate the output signal of the ADC; an AGC controller configured to output, in an AGC period, a gain code corresponding to the prescribed gain to be set in the VGA; and a VGA gain corrector configured to correct the prescribed gain by a prescribed amount, wherein the AGC controller sets a cutoff frequency of the at least one HPF to a second cutoff frequency that is higher than the first cutoff frequency at a start of the AGC period, and sets the cutoff frequency of the at least one HPF to the first cutoff frequency before an end of the AGC period; and wherein the VGA gain corrector sets a correction amount of the prescribed gain to a first correction amount after the setting of the cutoff frequency of the at least one HPF to the second cutoff frequency, and sets the correction amount of the prescribed gain to a second correction amount that is smaller than the first correction amount after the setting of the cutoff frequency of the at least one HPF to the first cutoff frequency, wherein a difference between the first correction amount and the second correction amount is equal to a gain reduction amount of the wideband gain that occurs because of the setting of the cutoff frequency of the at least one HPF to the second cutoff frequency.