| 摘要 |
PURPOSE:To eliminate the need of adding a function to a transmitter and arbitrarily set delay time by selecting the lengths of optical fibers by adding a radio frequency signal upon which delayed waves are superimposed by adding outputs of the 1st variable-gain amplifier and plural 2nd variable-gain amplifiers to each other. CONSTITUTION:A radio frequency signal is inputted to the 1st variable-gain amplifier 130 after receiving Rayleigh fading at a Rayleigh fading simulator 120. Then delayed waves inputted to simulators 12a-12n are respectively sent to second variable-gain amplifiers 13a-13n after receiving Rayleigh fading at the simulators 12a-12n. The delayed waves are added to each other by means of a mixer 14 together with the output of the amplifier 130 and an output radio frequency signal 15 is obtained. The length of each optical fiber from the output of an electrooptical converter (E/O) 5 to the output of each optical connector 10a-10n is set so that desired delay time can be obtained. Therefore, a radio frequency signal upon which upto in delayed waves having infinitesimal time resolution overlap can be obtained. |
