High power, high conversion gain frequency doublers using SiC MESFETs and AlGaN/GaN HEMTs

Highly efficient 5.8‐GHz class E−1 frequency doubler using a transmission‐line‐based notch filter

“…The power level of the unwanted harmonic signal is as important as the output power and PCE in the frequency multiplier, because the minimization of the power level at the unwanted signals can reduce the noise at the output, and increase the PCE. 13 The unwanted harmonic power is represented by the maximum power, which is located near the output signal among the unwanted harmonics. The output F I G U R E 4 Measured S-parameters of the proposed frequency doublers: A, optimized at low driving power and B, optimized at high driving power [Color figure can be viewed at wileyonlinelibrary.com] frequency and the order of the frequency are also important to show the performance, because the output power decreases as the frequency order increases.…”

“…The output F I G U R E 4 Measured S-parameters of the proposed frequency doublers: A, optimized at low driving power and B, optimized at high driving power [Color figure can be viewed at wileyonlinelibrary.com] frequency and the order of the frequency are also important to show the performance, because the output power decreases as the frequency order increases. 13 The conversion frequency difference Δf, which is the difference between the fundamental and wanted harmonic frequencies, can act as a simple indicator of the frequency order and the input fundamental frequency. Because the PCE can represent DC power consumption, the input power level, and the wanted output power, the FoM can be expressed using the PCE, harmonic suppression, and the difference between input and output frequencies as…”