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A single-output, band selecting interposer is designed to combine three identical all-digital CMOS transmitter (Tx) chips. The open-drain CMOS Txs are flip-chip connected to the primary windings of three frequency selecting transformers realized on a single PCB interposer. The secondary windings of the three transformers are connected in series and they share a single output. Across 0.4 to 4 GHz, a peak power higher than 22.9 dBm is achieved collectively by the three sub-Txs with a drain efficiency (DE) better than 25%. The peak powers/DE of the three sub-Txs are 28.6 dBm/50%, 27.4 dBm/49%, and 24.7 dBm/34%, at 0.85, 2.1, and 3 GHz, respectively. This paper further demonstrates that the band selection can be achieved via reconfiguring the CMOS inverse Class-D switching power amplifiers. As demonstrated via continuous wave and 64-quadratic-amplitude modulation, WLAN, and LTE modulation tests, the reconfigurable Tx package exhibits high power and efficiency across all supported bands. [ABSTRACT FROM AUTHOR]

A 700-MHz to 1.6-GHz RF power digital-to-analog converter with programmable integrated harmonic cancellation and mixed-signal filtering is presented. Harmonic cancellation is implemented by splitting the power amplifier (PA) into segments, driving different segments of the PA with phase-shifted versions of the local oscillator (LO) signals, and summing at the output. Mixed-signal filtering is realized in a similar fashion but with segments driven with delayed versions of the input data. The phase shift and data delays are reconfigurable and implemented to operate across a wide frequency range. To boost efficiency, 25% duty cycle LO signals are used. A technique to correct for IQ constellation distortion induced by these 25% duty cycle LO signals is introduced and verified in measurements. The transmitter (TX) operates at a maximum sample rate of 500 MSa/s and achieves an output power of 25.6 dBm for an output load of 100 $\Omega $ when harmonic cancellation is enabled. The TX demonstrates 24–42 dB of 3rd harmonic cancellation for continuous wave signals across a 700-MHz to 2-GHz frequency range, achieving an HD3 as low as −57 dB. The TX achieves an HD3 reduction of 33 dB and an 18-dB notch at 40-MHz offset with 20-MHz long-term evolution data. [ABSTRACT FROM AUTHOR]

This paper demonstrates a wideband CMOS all-digital polar transmitter with flip-chip connection to three high-density-interconnection PCB interposers. The interposers are designed to extract power from a CMOS open-drain inverse Class-D power amplifier core. For a wide frequency range from 0.7 to 3.5 GHz, continuous-wave output power higher than 25.5 dBm and drain efficiency (DE) above 40% are demonstrated. The low-band package achieves a peak power of 29.2 dBm at 1.1 GHz with DE of 60%, the mid-band package outputs 28.8 dBm at 1.5 GHz with DE of 56%, and the high-band package generates 26 dBm at 3 GHz with DE of 49%. The amplitude modulation (AM) is achieved by digitally modulating the switch conductance of the inverse Class-D core, and the on-chip phase modulation is achieved by digitally weighing the in-phase and quadrature bias currents in the IQ mixer. Detailed modulation tests, involving 64 quadrature amplitude modulation (QAM) and 20-MHz WLAN and LTE signals, exhibit excellent power and efficiency at 0.6, 1.2, 1.8, 2.4, 3, and 3.6 GHz. The associated specifications on spectral masks and error vector magnitudes are satisfied. [ABSTRACT FROM AUTHOR]

This paper demonstrates a wideband CMOS all-digital polar transmitter with flip-chip connection to three high-density-interconnection PCB interposers. The interposers are designed to extract power from a CMOS open-drain inverse Class-D power amplifier core. For a wide frequency range from 0.7 to 3.5 GHz, continuous-wave output power higher than 25.5 dBm and drain efficiency (DE) above 40% are demonstrated. The low-band package achieves a peak power of 29.2 dBm at 1.1 GHz with DE of 60%, the mid-band package outputs 28.8 dBm at 1.5 GHz with DE of 56%, and the high-band package generates 26 dBm at 3 GHz with DE of 49%. The amplitude modulation (AM) is achieved by digitally modulating the switch conductance of the inverse Class-D core, and the on-chip phase modulation is achieved by digitally weighing the in-phase and quadrature bias currents in the IQ mixer. Detailed modulation tests, involving 64 quadrature amplitude modulation (QAM) and 20-MHz WLAN and LTE signals, exhibit excellent power and efficiency at 0.6, 1.2, 1.8, 2.4, 3, and 3.6 GHz. The associated specifications on spectral masks and error vector magnitudes are satisfied. [ABSTRACT FROM PUBLISHER]

A wide-tuning-range low-power sigma-delta-based direct-RF-to-digital receiver architecture is implemented in 65 nm CMOS. A flat signal transfer function is chosen to support wide-frequency-range radios. A multilevel (two-bit) nonreturn-to-zero DAC improves jitter immunity to enable a high dynamic range, and, with a class-AB low-noise transconductance amplifier, guarantees a highly linear front end. For a 4 MHz signal, the peak SNDR of the receiver exceeds 68 dB and is better than 60 dB across the 400 MHz to 4 GHz carrier frequency range. By virtue of utilizing a negative feedback digitizer close to the antenna, an IIP3 of +10 dBm is achieved while dissipating only 40 mW from 1.1 V/1.5 V supply voltages. [ABSTRACT FROM AUTHOR]

We present an ultra-wideband transceiver designed for ultra-low-power communication at sub-10 cm range. The transceiver operates at a 5.6 GHz carrier frequency, chosen to minimize path loss when using a 1 cm^2 antenna, and can switch its architecture between self-synchronous rectification and low-IF to adapt its power consumption to the channel characteristic in real time. A low-power digital circuit exploits redundancy in the modulation scheme to provide a real-time BER estimate used to close the mode-switching loop. Implemented in 65 nm CMOS, the transceiver consumes 25 \mu\W when transmitting and 245\ \mu\W when receiving in low-power mode, plus 45\ \mu\W in the clock generator, and only requires an external antenna. Dual-mode operation allows range extension and mitigates interference. [ABSTRACT FROM AUTHOR]

This paper describes a low power and element-scalable 60 GHz 4-element phased array transceiver implemented in a standard 65 nm CMOS process. Using a 1.2 V supply, the array consumes < 34 mW/element including LO synthesis and distribution. Energy and area efficiency are achieved by utilizing a baseband phase shifting architecture, holistic impedance optimization, and lumped-element based design. Each receiver (RX) element provides 24 dB of gain with an average noise figure (NF) of 6.8 dB while the total saturated output power of the transmitter (TX) is 4.5 dBm. The array achieves 360^\circ of phase shifting range with a worst-case measured phase resolution of 6 bits (TX)/ 5 bits (RX) while maintaining amplitude variations less than \pm 0.5 dB. [ABSTRACT FROM AUTHOR]

This paper presents a low power 60 GHz transceiver that includes RF, LO, PLL and RB signal paths integrated into a single chip. The transceiver has been fabricated in a standard 90 nm CMOS process and includes specially designed ESD protection on all mm-wave pads. With a 1.2 V supply the chip consumes 170 mW while transmitting 10 dBm and 138 mW while receiving. Data transmission up to 5 Gb/s on each of I and Q channels has been measured, as has data reception over a 1m wireless link at 4 Gb/s QPSK with less than 10-11 BER. [ABSTRACT FROM AUTHOR]