Transformer matched gilbert mixer with active balun for D band transmitter

• Published in: Microwave and optical technology letters Vol. 62; no. 8; pp. 2696 - 2702
• Main Authors: Yu, Jiayang, Chen, Jixin, Li, Huanbo, Zhou, Peigen, Hou, Debin, Hong, Wei, Yan, Pinpin
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01-08-2020; Wiley Subscription Services, Inc
• Subjects: active balun; Baluns; Bandwidths; Broadband; Circuit design; Compression tests; D band transmitter; Gilbert mixer; Intermediate frequencies; Power consumption; transformer; Transformers
• ISSN: 0895-2477; 1098-2760
• DOI: 10.1002/mop.32219

A Gilbert mixer for the application of a D band transmitter is presented. In the work, the differential pair below the mixing quad is replaced by an active balun. A source resistor is introduced to improve balance performance of the active balun. Owing to the resistor, the LO‐to RF isolation of the mixer is also improved. At the output end, a transformer‐based balun is used to transform differential signal to single‐end signal and realize wideband output match. The circuit is designed on a 130 nm SiGe BiCMOS technology with fT/fmax of 300/500 GHz. The compact mixer covers 5 GHz intermediate frequency (IF) tuning range (1 to 6 GHz) with LO frequency fixed at 150 GHz. The measured RF 3‐dB bandwidth varying from 128 to 160 GHz with maximum −6 dB conversion gain, when the LO frequency is tuned. And the output referred 1‐dB compression point (OP1dB) is nearly −15 dBm. The mixer except test circuit consumes 14 mW DC power.