A Carrier-Suppressed Balance BPSK Modulator for Impulse Radio Ultra-Wideband Transmitter

A carrier-suppressed balance binary phase shift keying (BPSK) modulator for impulse radio ultra-wide band (IR-UWB) transmitter is proposed. The principle of the carrier-suppressed balance modulator is to split one local oscillator signal into two balance channels with 180deg out-of-phase through a 0/pi microstrip power splitter, then both signals are multiplied with two positive pulses respectively and at last two modulation signals converges at a single channel in the microstrip combiner. Leakage of carrier wave can be significantly suppressed because it is counteracted in the process of modulation. Furthermore, the proposed modulator has a lower error vector magnitude (EVM). And the stringent demanding of timing jitter is largely reduced compared to the noncoherent modulation scheme. The carrier-suppressed balance modulator is fabricated and measured in the end of the paper, which has a suppression improvement of 15.7 dB on carrier wave and a low value of EVM at 5.17%.