Circuit board antenna, wherein - the circuit board antenna comprises an electrically conductive first antenna structure on a first outer layer of a circuit board; - the circuit board antenna comprises an electrically conductive first reference region on the first outer layer; - the circuit board antenna comprises an electrically conductive supply line to the first antenna structure; - the first reference region fully encloses the first antenna structure, other than an isolating cutout for the supply line, so that an electrically isolating first free space is formed between the first antenna structure and the first reference region; - the circuit board antenna comprises an electrically conductive second antenna structure on a second outer layer of the circuit board; - the circuit board antenna comprises an electrically conductive second reference region on the second outer layer; - the second reference region fully encloses the second antenna structure, so that an electrically isolating second free space is produced between the second antenna structure and the second reference region; - the first antenna structure is connected to the second antenna structure of the circuit board antenna in an electrically conductive manner by way of one or more vias; and - the first reference region is connected to the second reference region in an electrically conductive manner by way of one or more vias of the circuit board antenna, characterised in that - the first antenna structure has a first width with a value of F ∗ 2.10mm ± 10% in a first region; and - the first antenna structure has a second width with a value of F ∗ 1.77mm ± 10% in a second region; and - the first antenna structure has an overall length with a value of F ∗ 12.52mm ± 10%; and - the second region of the first antenna structure has a partial length with a value of F*4.40mm ± 10%; and - F is an arbitrary real-valued scaling factor, where in particular F=1. - the circuit board antenna comprises an electrically conductive first antenna structure on a first outer layer of a circuit board; - the circuit board antenna comprises an electrically conductive first reference region on the first outer layer; - the circuit board antenna comprises an electrically conductive supply line to the first antenna structure; - the first reference region fully encloses the first antenna structure, other than an isolating cutout for the supply line, so that an electrically isolating first free space is formed between the first antenna structure and the first reference region; - the circuit board antenna comprises an electrically conductive second antenna structure on a second outer layer of the circuit board; - the circuit board antenna comprises an electrically conductive second reference region on the second outer layer; - the second reference region fully encloses the second antenna structure, so that an electrically isolating second free space is produced between the second antenna structure and the second reference region; - the first antenna structure is connected to the second antenna structure of the circuit board antenna in an electrically conductive manner by way of one or more vias; and - the first reference region is connected to the second reference region in an electrically conductive manner by way of one or more vias of the circuit board antenna, characterised in that - the first antenna structure has a first width with a value of F ∗ 2.10mm ± 10% in a first region; and - the first antenna structure has a second width with a value of F ∗ 1.77mm ± 10% in a second region; and - the first antenna structure has an overall length with a value of F ∗ 12.52mm ± 10%; and - the second region of the first antenna structure has a partial length with a value of F*4.40mm ± 10%; and - F is an arbitrary real-valued scaling factor, where in particular F=1.