Transformer-Based Broadband High-Linearity HBT Gm-Boosted Transconductance Mixers

Journal article, 2014

A Gm-boosted transconductance configuration mixer is proposed. Based on this topology, two broadband monolithic InGaP HBT mixers, one single device and one balanced, have been developed for C-Ku-band applications. The single device mixer has a conversion gain of 4.5 +/- 1.5 dB within the RF frequency range from 5 to 17 GHz. The balanced design has about 3.5 +/- 1.5-dB conversion gain within a frequency range of 6-18 GHz. The two mixers have very good linearity with a third-order intermodulation intercept point (IIP3) higher than 16 and 20 dBm for the single device mixer and single balanced mixer, respectively. Both mixers are pumped by a local oscillator power of 5 dBm. To the authors' best knowledge, the designed mixers demonstrate the highest IIP3 with positive conversion gain in this frequency range. Compact designs are achieved with chip sizes less than 0.5 mm(2). DC power consumptions are 30 and 50 mW, for the single device and single balanced mixer, respectively.