Search

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]

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]