Silicon Photonic Radar Receiver IC for mm-Wave Large Aperture MIMO Radar Using Optical Clock Distribution

A silicon photonics millimeter-wave (mm-wave) radar receiver (RX) integrated circuit (IC) for a multiple-input–multiple-output (MIMO) imaging radar is presented. Optical clock distributed over fiber enables coherent operation of several transceiver frontends for large apertures and finer angular resolution in the MIMO imaging radars. All electronic and photonic components needed to receive the optical clock signal, the electronic radio frequency (RF) signal, and the in-phase quadrature (IQ) downconvertion to the baseband is integrated in the RX frontend IC. The RX chip supports optical clock signals at 1310- and 1550-nm optical wavelengths. The chip is implemented in IHPs pre-production photonic 250-nm SiGe BiCMOS technology. At an intermediate frequency (IF) of 1 MHz, the measured conversion gain (CG) is 6.95 dB at an RF of 66 GHz and −11.18 dB at an RF of 77 GHz from −5-dBm optical modulation amplitude (OMA) and −13-dBm RF power. The RX IC dissipates 770 mW and is operated with a single 3.6-V power supply. For the realization of an optical receive path, an off-chip lithium niobate (LiNbO3) Mach–Zehnder modulator (MZM) was used. The optical receive path achieves a saturated OMA of −6 dBm at an RF of 77 GHz and at an IF of 1 MHz.