Saleh Hassanzadehyamchi, Amirreza Alizadeh, Ali M. Niknejad, Omeed Momeni
This article proposes a novel approach on cascaded series-connected power amplifier (PA) design. High-frequency transistor modeling is employed to analyze the stacked cell, and a methodology is developed to maximize the output power ($P_\text{out}$) and power-added efficiency (PAE) of each cell. The$P_\text{out}$and power gain of the cell are studied, and the optimum operation point is determined. A proof-of-concept integrated PA is implemented in a 45-nm CMOS silicon-on-insulator (SOI) process, where stacking and parallel power combining techniques are adopted to achieve 18.7-dBm$P_\text{out}$and 4.8% PAE at 200 GHz. Each PA unit uses three cascaded gain stages where two-stacked, three-stacked, and five-stacked architectures are employed for the first, second, and third stages, respectively. Four PA units are power-combined by a low-loss 4:1 zero-degree combiner. The amplifier consumes 1.4-W dc power and has a small-signal gain of 14.6 dB at 203.2 GHz. The designed PA occupies$1.28\times1.05$mm$^\text{2}$die area, including all pads. To the author’s knowledge, the designed PA achieves the highest$P_\text{out}$and PAE among all the Si counterparts at 200 GHz.
Advanced Power Amplifier Design
Radio Frequency Integrated Circuit Design
Electromagnetic Compatibility and Noise Suppression
This paper presents an all-passive negative feedback network that performs autonomous radio-frequency (RF) front-end beam-forming and dynamic beam-tracking toward the direction of the incident RF signal. The proposed feedback network consists of a passive RF signal processing network, voltage rectifiers, and voltage-controlled delay-line phased shifters, all of which are passive-only circuits. The negative feedback loop is realized by passive phase detection, phase-to-voltage conversion, and voltage-controlled phase shifting, achieving a large loop-gain and autonomous operation with zero DC power consumption. The nonlinear behavior of the loop is exploited to substantially expand the array field of view (FoV). A proof-of-concept broadband four-element all-passive self-steering beam-former at 5 GHz with a wide FoV is implemented in a standard 130 nm CMOS process. A high-quality four-element synthesized array factor is measured for the input progressive phase shift φinfrom -180° to 180°. When the proposed negative feedback loop is enabled, the normalized array factor is -2.87/-2.8 dB at φin= +90°/-90° with an input RF power Pin of -17 dBm/element at 5 GHz, achieving >25 dB array factor improvement over the open-loop operation. Moreover, the nonlinear feedback loop allows for significant array factor improvement even at φin= +180°/-180°. The proposed beam-former also achieves high-quality self-steering beamforming from 4 to 5.68 GHz with 34.7% fractional bandwidth. Therefore, the proof-of-concept all-passive self-steering beamformer outperforms the state-of-the-art active designs in terms of beam-forming quality, FoV, and fractional bandwidth. To the best of the authors' knowledge, this is the first demonstration of an all-passive negative feedback network for a broadband and wide FoV self-steering beam-forming with zero DC power consumption.
This paper presents an all-passive negative feedback network to perform autonomous RF front-end beam-forming towards the direction of the incident RF beam. The beam-forming front-end block consists of a passive network for RF signal processing, voltage rectifiers, and voltage-controlled phase shifters, all of which are passive components and consume zero DC power. A proof-of-concept 4-element self-steering beam-forming block at 5GHz is implemented in a standard 130nm CMOS process and occupies an area of 4.1mm2. The measurements demonstrate that a high-quality 4-element array factor is successfully synthesized for the input progressive phase shift from -120° to +120°. At an input power Pin of -17dBm/element, the normalized array factor is -4.3dB/-3.2dB at +90°/-90° input progressive phase shift in the closed-loop operation, out-performing reported active self-steering beam-formers. To the best of our knowledge, this is the first demonstration of an all-passive network for front-end self-steering beam-forming with zero DC power.