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This paper proposes a new closed-form expression for computing the power efficiency of delta-sigma (DS) radio frequency (RF) transmitters. Due to the large bandwidth of the pulsewidth modulated (PWM) signal at the output of the DS modulator, the peak efficiency of the power amplifier (PA) when driven by a PWM signal is considerably different than its peak(More)
This paper presents the design of concurrent multiband Doherty power amplifiers (MB-DPA) based on a newly developed multiband impedance inverter network (MB-IIN). The design concept can theoretically be applied to a large number of frequency bands. To support the design of MB-DPAs, a detailed realization of the MB-IIN is introduced for the first time. For(More)
This paper presents an RFDAC based transmitter for wireless mobile and connectivity applications in a 65 nm CMOS technology. The transmitter RFDAC has a segmented architecture employing 4 LSB and 16 MSB unit cells for each I and Q path, thus providing a resolution of 8 bit + signum. Switchable LO drivers and unit cells with current shutdown are used to(More)
This paper presents a fully integrated adaptive multiband multimode switching-mode power amplifier (SMPA) in CMOS technology. The power amplifier (PA) module, consisting of input matching, driver, output stage, load transformation network (LTN), and auxiliary circuitry, utilizes optimized driving waveforms to increase output power and efficiency of a SWPA.(More)
This paper presents a novel energy-efficient multi-standard multilevel LINC transmitter architecture. The proposed system is able to provide a large number of reconfigurable multiple levels by arbitrarily controlling the output power of the two efficient power amplifiers. The novelty of the architecture relies in the efficient generation of the arbitrary(More)
This paper presents a low power high performance frequency synthesizer. Based on the current-reuse VCO architecture, the whole system power consumption is significantly saved with excellent phase noise performance. Imbalance amplitude problems caused by the unsymmetrical VCO are solved by the pre-tuning mechanism, which automatically chooses the correct(More)