| 摘要 |
PROBLEM TO BE SOLVED: To provide a radio communication device which prevents a communication quality from being lowered due to noise and prevents a communication quality from being lowered because a circuit is saturated by noise. SOLUTION: A signal band of the radio communication device is set to a band which is not overlapped on a band of noise which is emitted from a noise generation source such as an electronic oven. When the amplitude of noise that passes through a high frequency band pass filter 11 is smaller than threshold Vth, a gain controlling means 18 does not operate. In such cases, noise is eliminated by a base band low pass filter 16. On the other hand, when the amplitude of noise that passes through the filter 11 is larger than the threshold Vth, the means 18 lowers the gain of a high frequency band pass filter 12. This prevents a high frequency amplifier 12 and a frequency mixer 13 from being saturated with noise and prevents a signal from being distorted by saturation and a communication quality from being lowered. Also, the means 18 increases the gain of the base band amplifier 16 to compensate gain that is suppressed by high frequency amplification 32. |
