A Frequency Quadrupler in 130-nm SiGe With Stack Multiport-Driven Matching Achieving 37.4% Instantaneous Bandwidth

In this letter, a wideband and high harmonic rejection frequency quadrupler, which consists of a two-stage push–push pair frequency doubler, is demonstrated in a 130-nm SiGe technology. A novel stack multiport-driven matching (SMDM) technology is employed in inter-stage matching to address the limited bandwidth, providing a more efficient method to match the dual-tank networks to 50
$\Omega $
. The SMDM also provides dc pass-through with the common-base (CB) amplifier, thereby increasing the conversion gain (CG). Additionally, the undesired harmonics are suppressed by the dual-tank networks loaded on the collector of the two-stage doubler. The measured results show that the 3-dB bandwidth of the output power is about 6.8 GHz from 14.8 to 21.6 GHz, that is, 37.4%. The worst-case harmonic rejection ratios (HRRs) are 22.1 dBc at the second-order harmonic, 44.4 dBc at the fundamental harmonic, and 35.7 dBc at the third-order harmonic with input power 2 dBm over the entire operating bandwidth, respectively. The frequency quadrupler occupies an area of
$0.83\times0.5$
mm2.