Design and analysis of a wideband compact LNA-mixer in millimeter wave frequency

Abstract

This paper presents the design and analysis of a millimeter-wave LNA-mixer, which adopts a low-noise single-to-differential conversion balun with low phase (gain) imbalance, using a common-source and a common-gate stage. Each stage employs a cascode transistor with inductors in the gate and source for improving noise, gain, and bandwidth performance. A new transformer-based network is proposed for broadband input matching. Also, a transformer network couples between transconductance and switching stage for independent biasing of two stages, which provides passive gain without extra power consumption and further noise reduction. To optimize the size of transistors and their current density, a new figure of merit is utilized which concurrently optimize noise performance, cut-off frequency, and transconductance efficiency. The input frequency range is 27.5–43.5 GHz with typical input signal power of – 40 dBm and a switching signal power of 0dBm, using 0.18 µm CMOS technology. The simulation result shows that typical conversion gain is 24–27 dB, DSB-NF is 5.33–9.1 dB, and third-order intercept point is − 7.83 dBm. The DC power consumption is 11.13 mW with a chip size of 0.45 mm2.