A QPSK/16-QAM OFDM-based 29.1Mbps LINC transmitter for Body Channel Communication

A low power and glitch-free circular rotation phase modulator for outphasing transmitter

“…The fine stage and extra stage employs DCV to achieve required phase resolution. In this approach, each delay stage consists of an inverter driving a 5-bit Due to the constant delay caused by MUX cells in the power-of-two schemes [3,10,11], the 0°phase is always indicated by the constant delayed signal instead of the original input signal. Therefore, a CDC circuit is proposed to get relative 0°phase for determining the changing time of the enable signals, which is essential for the circular phase shift.…”

“…Note that, with circular rotation phase shift, the 8-bit delay line can achieve maximum control code of 512. In addition, for fair comparisons, conventional structure in [3] and the AND-gated architecture in [10] were also designed and simulated in the same condition. As shown in Fig.…”

“…Digital outphasing transmitter with switch-mode power amplifier (SMPA) [1,2,3] have recently become a focus of research and development activity due to its less circuit complexity and lower power consumption [2,3,4,5,6]. Phase modulator (PM), as an essential part of outphasing transmitters, has been widely discussed by many researchers [2,3,4,5,6,7,8,9,10]. The author in [2] propose a sub-mW achievement with simple power-of-two structure.…”

“…However, unnecessary inverse leads into power dissipation and the asynchronous control causes pulse-shortening problem. To reduce power overhead, implementation in [10] employs a continuous locking scheme. Although this approach minimize power consumption by gating the un-working path, it still suffers from glitch and pulse-shortening problems.…”

Multi-scheme PSK and QAM modulator through vector scaling and summation

“…Phase-Shift Keying (PSK) and Quadrature Amplitude Modulation (QAM) are two classic modulation schemes that have given rise to a multitude of different circuits. However, few modulation architectures [2], [3] have attempted to carry out multiple modulation schemes with the same design.…”