An array antenna comprising: - at least one row of radiating elements (Eij), each radiating element being adapted for individually producing emission radiation from an electrical excitation signal received by said radiating element; - a control unit acting as a beamformer; - at least one delay line (Li), which is comprised of a serial assembly of line patterns (Mij), each line pattern being adapted for retransmitting an electromagnetic signal received at input by said line pattern, with a variable delay to the next line pattern within the delay line, so that the electromagnetic signal constitutes a guided traveling wave which propagates along the delay line from a feed end of said delay line, and each line pattern being provided with at least one control input making it possible to vary the delay produced by said line pattern for the electromagnetic signal; and - excitation links (Lij), coupling each line pattern (Mij) of the delay line (Li) one-to-one to one of the radiating elements (Eij) of the row of radiating elements, each excitation link being adapted for transmitting to the corresponding radiating element, as an electrical excitation signal for said radiating element, an electrical signal which corresponds to a phase of the guided traveling wave as existing at the line pattern coupled by said excitation link, the row of radiating elements and the delay line thus coupled to each other forming an antenna line, the control unit being adapted for transmitting to the at least one control input of each line pattern, an individual command which determines a value of the delay produced by said line pattern for the electromagnetic signal, so that the control unit determines, by means of the individual commands, a direction of emission of radiation by the array antenna, wherein each line pattern (Mij) comprises at least one delay cell unit, said delay cell unit comprising at least one first capacitor of variable capacitance (V1, V2), and at least one conducting track meander line which is combined with a second capacitor of variable capacitance (V3, V4), in order to produce a variable inductance value, and said line pattern is arranged so that the individual command that is transmitted by the control unit to the control input of said line pattern determines capacitance values of said first and second capacitors, the array antenna being characterized in that it further comprises a shielding structure (21, 22) arranged near the delay line (Li), so as to at least partially mask radiations produced by the line patterns (Mij) of said delay line, without significantly masking the emission radiations produced by the radiating elements (Eij) coupled to said line patterns. - at least one row of radiating elements (Eij), each radiating element being adapted for individually producing emission radiation from an electrical excitation signal received by said radiating element; - a control unit acting as a beamformer; - at least one delay line (Li), which is comprised of a serial assembly of line patterns (Mij), each line pattern being adapted for retransmitting an electromagnetic signal received at input by said line pattern, with a variable delay to the next line pattern within the delay line, so that the electromagnetic signal constitutes a guided traveling wave which propagates along the delay line from a feed end of said delay line, and each line pattern being provided with at least one control input making it possible to vary the delay produced by said line pattern for the electromagnetic signal; and - excitation links (Lij), coupling each line pattern (Mij) of the delay line (Li) one-to-one to one of the radiating elements (Eij) of the row of radiating elements, each excitation link being adapted for transmitting to the corresponding radiating element, as an electrical excitation signal for said radiating element, an electrical signal which corresponds to a phase of the guided traveling wave as existing at the line pattern coupled by said excitation link, the row of radiating elements and the delay line thus coupled to each other forming an antenna line, the control unit being adapted for transmitting to the at least one control input of each line pattern, an individual command which determines a value of the delay produced by said line pattern for the electromagnetic signal, so that the control unit determines, by means of the individual commands, a direction of emission of radiation by the array antenna, wherein each line pattern (Mij) comprises at least one delay cell unit, said delay cell unit comprising at least one first capacitor of variable capacitance (V1, V2), and at least one conducting track meander line which is combined with a second capacitor of variable capacitance (V3, V4), in order to produce a variable inductance value, and said line pattern is arranged so that the individual command that is transmitted by the control unit to the control input of said line pattern determines capacitance values of said first and second capacitors, the array antenna being characterized in that it further comprises a shielding structure (21, 22) arranged near the delay line (Li), so as to at least partially mask radiations produced by the line patterns (Mij) of said delay line, without significantly masking the emission radiations produced by the radiating elements (Eij) coupled to said line patterns.