Patent ID: 8688153

Claim:
A signal transmission apparatus comprising: a plurality of modulating sections respectively configured to modulate a transmission object signal into a modulated signal; and a plurality of demodulating sections configured to demodulate the modulated signals, wherein respective sets of the modulating sections and the demodulating sections are configured to utilize a unique carrier frequency, wherein a frequency of a third-order intermodulation distortion component generated on a basis of two adjacent carrier frequencies is not present within any of reception bands of modulated signals based on each of the other carrier frequencies wherein three adjacent carrier frequencies satisfy the following conditions: where a first frequency difference is defined as a difference between a lowest carrier frequency and an intermediate carrier frequency of the three adjacent carrier frequencies, a second frequency difference is defined as a difference between a highest carrier frequency and the intermediate carrier frequency of the three adjacent carrier frequencies, and a small frequency difference is defined as the smaller of the first frequency difference and the second frequency difference, a first condition that a sum of a reception bandwidth on a higher-frequency side of the lower component frequency of the small frequency difference and a reception bandwidth on a lower-frequency side of the higher component frequency of the small frequency difference is smaller than the small frequency difference; a second condition that, where the first frequency difference is the small frequency difference, the difference between the second frequency difference and the first frequency difference is larger than the greater of a reception bandwidth on the lower-frequency side of the lowest carrier frequency and a reception bandwidth on the lower-frequency side of the highest carrier frequency; and a third condition that, where the second frequency difference is the small frequency difference, the difference between the first frequency difference and the second frequency difference is larger than the greater of a reception bandwidth on a higher-frequency side of the lowest carrier frequency and a reception bandwidth on a higher-frequency side of the highest carrier frequency.