A vertical broadband monopole antenna for vehicles for two frequency bands, namely a lower band for lower frequencies and an upper band for higher frequencies, separated by a frequency gap and both disposed in the decimeter wave spectrum, for transmitting and/or receiving using terrestrially broadcast, vertically polarized radio signals over a substantially horizontal conductive base surface as a vehicle ground having an antenna connection site located in the monopole nadir, comprising the following features: - the broadband monopole antenna is configured from a first and a further electrically conductive structure which are each oriented above and substantially perpendicular to the base surface; - the first electrically conductive structure comprises at the lower end of the broadband monopole antenna at least one triangular structure standing on its apex and having a substantially horizontally oriented baseline, the apex of said triangular structure forming an antenna connection point of the antenna connection site; - the first electrically conductive structure comprises, adjacent to and beneath the upper end of the broadband monopole antenna, a first roof capacitor substantially designed as a first rectangular structure; - the triangular structure and the first rectangular structure are inductively connected with high impedance by at least one first conductor strip (15, 15a, 15b) for separating radio signals in the upper band; - the further electrically conductive structure comprises a further roof capacitor which is guided substantially in parallel with the first rectangular structure, which is configured as a further areal structure, which is capacitively coupled to the first roof capacitor, and which is in particular substantially formed as a rectangular structure; - the further electrically conductive structure comprises at least one further conductor strip (39, 39a) of inductively high impedance for the separation of radio signals in the upper band that, connected to the further areal structure, extends towards the conductive base surface and is conductively connected thereto at its lower end, - wherein the triangular structure is configured by strip-shaped lamellas (20, 20a, 20b, 30, 30a, 30b) arranged in the manner of a fan and running together at the apex in the triangular plane. - the broadband monopole antenna is configured from a first and a further electrically conductive structure which are each oriented above and substantially perpendicular to the base surface; - the first electrically conductive structure comprises at the lower end of the broadband monopole antenna at least one triangular structure standing on its apex and having a substantially horizontally oriented baseline, the apex of said triangular structure forming an antenna connection point of the antenna connection site; - the first electrically conductive structure comprises, adjacent to and beneath the upper end of the broadband monopole antenna, a first roof capacitor substantially designed as a first rectangular structure; - the triangular structure and the first rectangular structure are inductively connected with high impedance by at least one first conductor strip (15, 15a, 15b) for separating radio signals in the upper band; - the further electrically conductive structure comprises a further roof capacitor which is guided substantially in parallel with the first rectangular structure, which is configured as a further areal structure, which is capacitively coupled to the first roof capacitor, and which is in particular substantially formed as a rectangular structure; - the further electrically conductive structure comprises at least one further conductor strip (39, 39a) of inductively high impedance for the separation of radio signals in the upper band that, connected to the further areal structure, extends towards the conductive base surface and is conductively connected thereto at its lower end, - wherein the triangular structure is configured by strip-shaped lamellas (20, 20a, 20b, 30, 30a, 30b) arranged in the manner of a fan and running together at the apex in the triangular plane.