A 1.14mW 750kb/s FM-UWB transmitter with 8-FSK subcarrier modulation

A Low-Power Low-Complexity Transmitter for FM-UWB Systems

“…This work focuses on the proposed transmitter architecture, which is different from the existing transmitter configurations [4,5,7,[9][10][11][12][13][14]. From similarity degree, this work is close to [9]. Both have sameness and differences.…”

“…The existing receiver [8] with dual band-pass filters (BPFs) is difficult to make the BPF center frequency accurately tuned under wide frequency ranges. The existing transmitter [9] with low power dissipation employs a multi-phase phase-locked loop (PLL) along with a pre-tuned relaxation VCO for subcarrier generation, which increases the hardware cost. The existing transmitters [10,11] based on direct-digital frequency synthesis (DDFS) encounter limited data rate (DR) or subcarrier frequency deviation (f 2 -f 1 ).…”

“…The frequency modulated UWB (FM-UWB) system generates a constant-envelope UWB signal with wideband frequency modulation (FM), featuring a flat inband power spectral density (PSD) and a steep spectral roll off to enable a well-defined RF bandwidth [4][5][6][7][8][9][10][11][12][13][14]. Fig.…”

High-Robust Relaxation Oscillator with Frequency Synthesis Feature for FM-UWB Transmitters

“…The existing oscillator [14] encounters slight f OSC shift under power supply variations. Although these oscillators have better PVT feature than those [3][4][5][6], they either could not generate the desired triangular waveforms, or have no the frequency synthesis (FS) function, namely, f OSC is not linearly tuned by a digital control signal. Hence, they are not perfect for 2-FSK triangular subcarrier generation.…”

“…Fig. 1 shows the block diagram of FM-UWB transmitters employing fractional-N phase-locked loop (PLL) with relaxation VCO for subcarrier generation [5,6].…”