D-Band Cascode Up conversion Mixer Utilizing Double Mixing Technique for Enhanced Linearity and Output Power in 130-nm SiGe Process

This article presents a D-band cascode balanced up conversion mixer in a 130-nm SiGe process. The proposed mixer employs a double mixing technique in its cascode configuration, where the local oscillator (LO) and intermediate frequency (IF) signals are applied at the base of the common-emitter (CE) configured transistor, and the common-base (CB) configured transistor remixes the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f_{\mathrm {LO}}$</tex-math> </inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f_{\mathrm {IF}}$</tex-math> </inline-formula> signals at the collector of the CE transistor, generating additional RF signal power and thereby enhancing the overall mixing process. This up conversion mixer achieves a saturation output power of 5.9 dBm with a dc power consumption of only 69 mW. The measured output referred 1-dB compression point (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathrm{OP}_{\text {1 dB}}$</tex-math> </inline-formula>) is 4.8 dBm. The measured peak conversion gain (CG) of the mixer is 9.8 dB at 139 GHz, with 3-dB bandwidth exceeding 30 GHz for different LO/IF powers. The LO-RF isolation is below −40 dB across the 120–170-GHz range. The chip size is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$620\times 360~\mu $</tex-math> </inline-formula>m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. This mixer exhibits superior performance concerning output power and linearity as well as core chip area.