This paper presents an RFDAC based transmitter for wireless mobile and connectivity applications in a 65nm cmos technology. The transmitter RFDAC has a segmented architecture employing 4 LSB and 16 MSB unit cells for ...
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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...
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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 reduce power dissipation when transmitting signals with high PAPR such as IEEE 802.11 (WLAN) or 3GPP Long Term Evolution (LTE). The frontend is capable of transmitting an 64 QAM-OFDM WLAN signal at a center frequency of 1 GHz with an output power of -8 dBm and an EVM of 4.66 %. Analog power dissipation is 34 mW, clock and LO divider use less than 10 mW, and the digital block consumes about 87 mW. The area of the frontend is about 0.4 mm 2 .
A double-harmonic-tuned LC tank (DHT tank) is proposed for significant phase-noise suppression in cmos voltage-controlled oscillator (VCO). The DHT tank presents open at the fundamental and third harmonic and short at...
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This paper assesses the impact of two modelling approaches for the nonlinear drain-source and gate-drain capacitances in a switch-based GaN HEMT model on predicting large-signal and switching-mode device performance. ...
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This paper assesses the impact of two modelling approaches for the nonlinear drain-source and gate-drain capacitances in a switch-based GaN HEMT model on predicting large-signal and switching-mode device performance. The extracted values for these intrinsic capacitors, derived from measured S-parameters in deliberate bias points, are modelled by a zeroth and first order approximation. Using these approximations in an in-house developed large-signal switch-based device model for GaN HEMTs, their effects on modelling accuracy of switching-mode operation at microwave frequencies are shown by comparing simulation and load-pull measurement results for inverse class-F operation. Whereas a zeroth order approximation is confirmed to provide good accuracy for both output power and efficiency prediction in saturation, the study shows that modelling the gate-drain capacitance with a linear equation instead of constant values extends the application range of the switch-based model to the linear region. Good agreement between large-signal simulation results and load-pull measurements in this operation mode has been obtained.
This paper proposes a methodology to design and optimize the footprint of miniaturized 3-dB branch-line hybrid couplers, which consists of high-impedance transmission lines and distributed capacitors. To minimize the ...
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