Wideband Balanced Photoreceivers with InP-based Photodiodes and 65 nm CMOS TIAs for use in Optical Frequency Synthesis Systems

Two photoreceivers, each comprised of a set of InP balanced photodiodes (PD) and one of two CMOS transimpedance amplifiers (TIA) fabricated in a 65 nm general-purpose process, are demonstrated in this paper. The balanced photodiodes achieve a responsivity of 0.65 A/W and a bandwidth of 12 GHz while driving a 50  $\bf \Omega$ load. The first photoreceiver uses a 9 GHz bandwidth regulated cascode (RGC) TIA with 59 dB $\bf \Omega$ transimpedance, achieving a maximum conversion gain of 1289 V/W and a minimum noise equivalent power (NEP) of 13 pW/ $\bf \sqrt{Hz}$ . The second photoreceiver utilizes an 11 GHz bandwidth modified current-reuse regulated cascode (CRRGC) TIA with 63 dB $\bf \Omega$ transimpedance gain, resulting in a maximum conversion gain of 2083  V/W and minimum NEP of 13 pW/ $\bf \sqrt{Hz}$ .