Experimental results obtained on a new circuit topology of a broadband and low spurious frequency doubler

The performances of a frequency doubler based on a distributed amplifier are evaluated experimentally. The gate and drain artificial transmission lines have band-pass filter frequency behavior, centered on the fundamental and second harmonic, respectively. The circuit topology of this frequency doubler makes possible a significant reduction of the power level for the output fundamental and third harmonics. The frequency doubler characterized in this paper has the experimental values of the conversion loss less than 4 dB and 7 dB, when the input power level is equal to -1 dBm and 5 dBm, respectively, for the input frequency ranging between 4 GHz and 6 GHz.