OOK/BPSK-Modulated Impulse Transmitters Integrated With Leakage-Cancelling Circuit

A time-gating technique is adopted to design an on-off keying (OOK) and a binary phase-shift keying (BPSK) ultra-wideband impulse transmitters, respectively. A leakage-cancelling technique is proposed to suppress leakage signal from the oscillator, which is implemented by integrating a leakage-cancelling circuit with the output buffer of the OOK transmitter and the modulator of the BPSK transmitter, respectively. These two types of transmitters have been implemented using 0.18-μ m RF CMOS technology. The measured leakage overshoot is less then 1.5 dBc in the OOK transmitter, and is negligible in the BPSK version.