The present application provides an adjustable radio frequency unit, a filter, and an electronic device. The adjustable radio frequency unit includes a first tunable dielectric layer and a second tunable dielectric layer; a first conductive layer located between the first tunable dielectric layer and the second tunable dielectric layer; a second conductive layer located on the side, away from the first conductive layer, of the first tunable dielectric layer; and a third conductive layer located on the side, away from the first conductive layer, of the second tunable dielectric layer; wherein orthographic projections of the first conductive layer, the second conductive layer and the third conductive layer on the first tunable dielectric layer at least partially overlap with one another. The adjustable radio frequency unit has the characteristic of passband adjustability and with high adjustment precision, good controllability, wide working frequency range, and low loss and cost.