Broadband low-phase-error variable gain amplifier adopting degenerated inductance technology

The invention belongs to the field of radio frequency integrated circuits, and particularly provides a 150-170GHz broadband low-phase-error variable gain amplifier adopting a degenerated inductance technology, which is used for effectively reducing the phase error between different gain gears and effectively expanding the bandwidth at the same time. The variable gain amplifier is composed of four variable gain amplifier unit circuits which are cascaded in sequence, each variable gain amplifier unit circuit introduces a phase compensation inductor MTL at an intermediate node of a common base tube and a common emitter tube on the basis of a current steering type cascade structure, and by designing the inductance value (MTLN or MTLP) of the phase compensation inductor MTL, the gain of the variable gain amplifier unit circuit is improved. The front two-stage unit circuit and the rear two-stage unit circuit realize different gain-phase characteristics (reverse conversion or synchronous conversion); and finally, ph