A broadband antenna system for a vehicle, comprising: - a ground plane circumscribed by a rectangle having major and minor sides, - a dielectric substrate comprising a main surface with a first portion area and a second portion area, the second portion area allocating the ground plane, wherein the ground plane surrounds two adjacent sides of the first portion area; - a radiating element for operating at at least one frequency band of operation, the radiating element having a substantially triangular shape disposed on the first portion area of the substrate, and having at least three angles and three sides, a first side being substantially aligned with the minor sides of the circumscribed rectangle and a first angle having an apex of the triangular shape, the apex being the closest point of the radiating element to the ground plane, - a grounding point disposed at one extreme of the first portion area of the substrate and coupled to the ground plane, the extreme located adjacent to the minor side of the circumscribed rectangle closest to the radiating element, - a feeding element electromagnetically coupled with the radiating element through the apex of the first angle, and - a conductive element, electrically isolated from the radiating element, disposed on the first portion area of the substrate and coupled to the grounding point, the conductive element having at least a first portion extending towards one of the major sides of the circumscribed rectangle and located between the radiating element and one of the sides of the first portion area of the substrate, - wherein each major side of the ground plane has an electric length (Lgp) of at least 0.13λ, being λ the lowest frequency of the antenna system, and - wherein the first angle of the radiating element has an aperture lower than 156°, - and wherein the conductive element has an electric length (Lce), the sum of the electric length (Lgp) of the major side of the circumscribed rectangle of the ground plane and the electric length (Lce) of the conductive element ranging from 0.18λ to 0.22λ, being λ the lowest frequency of the broadband antenna system. - a ground plane circumscribed by a rectangle having major and minor sides, - a dielectric substrate comprising a main surface with a first portion area and a second portion area, the second portion area allocating the ground plane, wherein the ground plane surrounds two adjacent sides of the first portion area; - a radiating element for operating at at least one frequency band of operation, the radiating element having a substantially triangular shape disposed on the first portion area of the substrate, and having at least three angles and three sides, a first side being substantially aligned with the minor sides of the circumscribed rectangle and a first angle having an apex of the triangular shape, the apex being the closest point of the radiating element to the ground plane, - a grounding point disposed at one extreme of the first portion area of the substrate and coupled to the ground plane, the extreme located adjacent to the minor side of the circumscribed rectangle closest to the radiating element, - a feeding element electromagnetically coupled with the radiating element through the apex of the first angle, and - a conductive element, electrically isolated from the radiating element, disposed on the first portion area of the substrate and coupled to the grounding point, the conductive element having at least a first portion extending towards one of the major sides of the circumscribed rectangle and located between the radiating element and one of the sides of the first portion area of the substrate, - wherein each major side of the ground plane has an electric length (Lgp) of at least 0.13λ, being λ the lowest frequency of the antenna system, and - wherein the first angle of the radiating element has an aperture lower than 156°, - and wherein the conductive element has an electric length (Lce), the sum of the electric length (Lgp) of the major side of the circumscribed rectangle of the ground plane and the electric length (Lce) of the conductive element ranging from 0.18λ to 0.22λ, being λ the lowest frequency of the broadband antenna system.