US Patent 7953136 Transmission circuit and system for the same

According to the present invention, there is provided a transmission circuit transmitting a power signal using frequency hopping system from an antenna connected to the transmission circuit through a transmission path, the transmission circuit including: a controller outputting an amplitude set value for each hopping frequency of the power signal before being transmitted according to power level of the power signal at the antenna; a pre-driver controlling the amplitude of the power signal before being transmitted for each hopping frequency according to the amplitude set value; and a power amplifier outputting the power signal to the transmission path according to the signal output from the pre-driver.