Electrical converter chosen from the group consisting of an inverter able to generate an AC voltage from a DC voltage and a rectifier able to generate a DC voltage from an AC voltage, this converter comprising: - a first and a second DC voltage port (4, 6) via which the DC voltage is received or delivered, - a first and a second AC voltage port (8, 10) via which the AC voltage is received or delivered, - a first inductor (Lf; Lf1, Lf2; Lfa, Lfb; Lf 100a, Lf 100b, L Pa, L Pb) and a controllable switch (I; Ia, Ib; I 100a, I 100b, I 102a, I 102b) that are connected in series between the first and second DC voltage ports (4, 6), the controllable switch comprising a first and a second power terminal and a control terminal, the controllable switch being connected to the first inductor via one of its power terminals, this switch being able, in response to a control signal received on its control terminal, to switch at a frequency greater than 1 MHz and reversibly, between: - a closed state in which its two power terminals are electrically connected to one another, and - an open state in which its two power terminals are electrically isolated from one another, - a second inductor (Ls; Ls1, Ls2; T; Lsa, Lsb; L SSa, L Lp, L SSb) flowed through by a current whose strength is modulated by the controllable switch, this second inductor and the switch being connected in series between the first and second AC voltage ports, characterized in that the converter comprises a piezoelectric resonator (30; 30a, 30b; 30 100a, 30 100b, R 104a, R 104b) comprising: - a first electrode connected directly to the first power terminal of the switch, - a second electrode connected directly to the second power terminal of the switch, and - a piezoelectric material interposed between the first and second electrodes; said piezoelectric resonator being able to eliminate even-order harmonics in the voltage through said controllable switch. - a first and a second DC voltage port (4, 6) via which the DC voltage is received or delivered, - a first and a second AC voltage port (8, 10) via which the AC voltage is received or delivered, - a first inductor (Lf; Lf1, Lf2; Lfa, Lfb; Lf 100a, Lf 100b, L Pa, L Pb) and a controllable switch (I; Ia, Ib; I 100a, I 100b, I 102a, I 102b) that are connected in series between the first and second DC voltage ports (4, 6), the controllable switch comprising a first and a second power terminal and a control terminal, the controllable switch being connected to the first inductor via one of its power terminals, this switch being able, in response to a control signal received on its control terminal, to switch at a frequency greater than 1 MHz and reversibly, between: - a closed state in which its two power terminals are electrically connected to one another, and - an open state in which its two power terminals are electrically isolated from one another, - a closed state in which its two power terminals are electrically connected to one another, and - an open state in which its two power terminals are electrically isolated from one another, - a second inductor (Ls; Ls1, Ls2; T; Lsa, Lsb; L SSa, L Lp, L SSb) flowed through by a current whose strength is modulated by the controllable switch, this second inductor and the switch being connected in series between the first and second AC voltage ports, characterized in that the converter comprises a piezoelectric resonator (30; 30a, 30b; 30 100a, 30 100b, R 104a, R 104b) comprising: - a first electrode connected directly to the first power terminal of the switch, - a second electrode connected directly to the second power terminal of the switch, and - a piezoelectric material interposed between the first and second electrodes; said piezoelectric resonator being able to eliminate even-order harmonics in the voltage through said controllable switch. - a first electrode connected directly to the first power terminal of the switch, - a second electrode connected directly to the second power terminal of the switch, and - a piezoelectric material interposed between the first and second electrodes; said piezoelectric resonator being able to eliminate even-order harmonics in the voltage through said controllable switch.