A 140-210-GHz InP Frequency Doubler Using a Low-Loss Low-Imbalance Marchand Balun

• Published in: IEEE microwave and wireless technology letters (Print) Vol. 34; no. 1; pp. 1 - 4
• Main Authors: Nguyen, Phat T., Shepard, Tyler, Wagner, Natalie, Stameroff, Alexander, Pham, Anh-Vu
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01-01-2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplification; Amplitudes; Baluns; Coplanar waveguides; Differential pair; frequency doubler; Frequency doublers; Gain; Harmonic analysis; harmonic generation; Insertion loss; Load matching; Marchand balun; Planar waveguides; Power generation; Probes; Rejection; wideband doubler
• ISSN: 2771-957X; 2771-9588
• DOI: 10.1109/LMWT.2023.3330828

This letter presents a 140-210-GHz frequency doubler using a low-loss, low-imbalance Marchand balun. By employing co-planar waveguide (CPW) multiconductor coupled lines (MCCLs), the modified balun achieves an insertion loss, amplitude, and phase imbalances of less than 1.5 dB, 0.3 dB, and 1.5<inline-formula> <tex-math notation="LaTeX">^{\circ}</tex-math> </inline-formula> across the 42-126-GHz bandwidth. When integrated with the doubler core, the balun's low phase and amplitude imbalances enable the doubler to provide high fundamental rejection and good conversion gain without additional amplifiers. The doubler core is power-matched using second harmonic load pull and a wideband output matching network. The 140-210-GHz frequency doubler exhibits a peak output power, conversion gain, and fundamental rejection ratio (FRR) of 6.5 dBm, 0 dB, and 42 dBc, respectively.