A voltage controlled oscillator, comprising: a first transistor having first (1502 1), second (1502 2) and third terminals (1502 3); a second transistor having first (1504 1), second (1504 2) and third terminals (1504 3); characterized by a circuitry comprising dynamically tuned coupled resonator networks (1524, 1528) coupled to the first terminals (1502 1, 1504 1) of each of the transistors (1502, 1504) through a tuning voltage network and a tunable phase coupling network, and further coupled to the third terminals (1502 3, 1504 3) of each of the transistors (1502, 1504); a dynamically tuned combiner network coupled between the second terminals (1502 2, 1504 2) of each of the transistors (1502, 1504) to combine output signals (1538, 1540) present at the second terminals (1502 2, 1504 2) into a signal operating at the second harmonic of the output signals (1538, 1540); and a phase detector coupled between the dynamically tuned coupled resonator networks (1524, 1528) and the dynamically tuned combiner network, configured to detect phase errors that occur between the output signals (1538, 1540) present at the second terminals (1502 2, 1504 2) of the first transistor and the second transistor and is operable to dynamically compensate by feeding back a signal based on the phase errors to the dynamically tuned combiner network and to the dynamically tuned coupled resonator networks (1524, 1528) during wideband operation so that each of the output signals (1538, 1540) remains in phase during a tuning operation, wherein the dynamically tuned coupled resonator networks (1524, 1528) comprise a pair of micro-strip coupled resonators arranged in a horse-shoe configuration, and wherein the voltage of the tuning network can be adjusted to tune an output signal (1538, 1540, 1550) of the voltage controlled oscillator over at least an octave frequency band by feeding back said signal based on the phase errors to the tunable phase coupling network, which keeps the first and second transistors (1502, 1504) operating in an anti-phase mode at an operating frequency of the output signals (1538, 1540) while the second harmonic interferes constructively over the octave band and to the dynamically tuned coupled resonator networks (1524, 1528) for tuning the phases and frequency respectively of the first and second transistors. a first transistor having first (1502 1), second (1502 2) and third terminals (1502 3); a second transistor having first (1504 1), second (1504 2) and third terminals (1504 3); characterized by a circuitry comprising dynamically tuned coupled resonator networks (1524, 1528) coupled to the first terminals (1502 1, 1504 1) of each of the transistors (1502, 1504) through a tuning voltage network and a tunable phase coupling network, and further coupled to the third terminals (1502 3, 1504 3) of each of the transistors (1502, 1504); a dynamically tuned combiner network coupled between the second terminals (1502 2, 1504 2) of each of the transistors (1502, 1504) to combine output signals (1538, 1540) present at the second terminals (1502 2, 1504 2) into a signal operating at the second harmonic of the output signals (1538, 1540); and a phase detector coupled between the dynamically tuned coupled resonator networks (1524, 1528) and the dynamically tuned combiner network, configured to detect phase errors that occur between the output signals (1538, 1540) present at the second terminals (1502 2, 1504 2) of the first transistor and the second transistor and is operable to dynamically compensate by feeding back a signal based on the phase errors to the dynamically tuned combiner network and to the dynamically tuned coupled resonator networks (1524, 1528) during wideband operation so that each of the output signals (1538, 1540) remains in phase during a tuning operation, wherein the dynamically tuned coupled resonator networks (1524, 1528) comprise a pair of micro-strip coupled resonators arranged in a horse-shoe configuration, and wherein the voltage of the tuning network can be adjusted to tune an output signal (1538, 1540, 1550) of the voltage controlled oscillator over at least an octave frequency band by feeding back said signal based on the phase errors to the tunable phase coupling network, which keeps the first and second transistors (1502, 1504) operating in an anti-phase mode at an operating frequency of the output signals (1538, 1540) while the second harmonic interferes constructively over the octave band and to the dynamically tuned coupled resonator networks (1524, 1528) for tuning the phases and frequency respectively of the first and second transistors.