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. <EOS>