A 29-Gb/s D-Band Gain-Boosted OOK Modulator With 60-dB On-Off Ratio in 28-nm CMOS

This paper presents a D-band on-off keying (OOK) modulator fabricated in a 28-nm CMOS process. A transformer-based gain-boosting structure is proposed to enhance the forward gain in the on state while achieving satisfactory impedance matching without increasing circuit complexity. Moreover, along with the symmetrical structure itself, the precisely designed physical signal routing further cancels the LO leakage in the off state, thereby significantly improving the on-off ratio. This single-stage modulator exhibits a measured peak forward gain of 4.7 dB at 151 GHz and achieves the highest single-stage on-off ratio among the D-band silicon-based OOK modulators, which exceeds 60 dB. The large-signal measurement reveals an output 1 dB compression point (OP<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub>) of -1.2 dBm while the on-off ratio surpasses 57 dB at the OP<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub>. The communication demonstration shows that the modulator supports a data rate of up to 29 Gb/s with a bit error rate (BER) of less than 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup>.