A 200-GHz Modulable Transceiver With 35-dB Tx On–Off Isolation and 16-Gb/s Code Rate for MIMO Radar in 130-nm SiGe Process

Abstract

This article describes a modulable 200-GHz trans- mitter (Tx) and receiver (Rx) chipset for multiple-input–multiple- output (MIMO) radar applications. To achieve signal modulation and orthogonality, a mode-switchable modulator and an ON–OFF isolation enhanced power amplifier (PA) are incorporated in the Tx. Based on this architecture, a simulated switching isolation exceeding 40 dB is realized even at PA saturation output. In addition, a compact, high-performance distributed balun design is proposed and analyzed, optimizing balanced-to- unbalanced performance and impedance matching. Moreover, the chipset features a wideband folded-dipole on-chip antenna with a vertical chip-to-waveguide transition for broadband radiation. The Rx includes a noise-canceling low-noise amplifier (LNA) and an IQ down mixer with a compact local oscillator (LO) generation network. The Tx chip exhibits a 3-dB saturated power bandwidth of 52 GHz and a maximum output power of 10.5 dBm, and the Rx chip exhibits a 42-GHz, 3-dB small- signal bandwidth, 24-dB conversion gain (CG), and 12-dB SSB NF. Enhanced by the isolation architecture, the chipset achieves switching isolation better than 35 dB within 170–230 GHz. Integration of the folded-dipole on-chip antenna generates a maximum equivalent isotropically radiated power (EIRP) of 12 dBm across a 4-dB bandwidth from 180 to 232 GHz. This performance is further enhanced to 28 dBm with a chip-to- waveguide transition connecting a WR-05 horn antenna. The modu