30MHz-18GHz ultra-wideband receiver

The invention discloses a 30MHz-18GHz ultra-wideband receiver, which has the functions of amplifying and down-converting ultra-wideband signals received by an antenna and outputting intermediate-frequency signals with lower frequency and bandwidth to a rear-end processor. The ultra-wideband receiver is of a two-time superheterodyne structure, the frequency spectrum of a signal with the frequency band ranging from 30 MHz to 18 GHz needs to be shifted to the frequency band below 4.1 GHz, the instantaneous bandwidth of the received signal has four types of 4 GHz/1 GHz/600 MHz/60 MHz, and the instantaneous bandwidth of 4 GHz only appears in the three frequency band signals of 2 GHz to 6 GHz, 8 GHz to 12 GHz and 10 GHz to 18 GHz. The receiver is composed of a low noise amplifier, various switches, an up-down converter, a filter/group, a numerical control attenuator, an amplifier and the like, 30 MHz to 18 GHz is divided into seven frequency band signals by adopting the filter/group and the switches, four signal fr