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This brief discusses an oscillator-based capacitive 3-D touch-sensing circuit for mobile devices. The proposed 3-D touch sensor uses correlated double sampling to achieve a high sensing resolution in the Z-direction and employs bootstrapping circuitry to reduce the mobile screen's interchannel-coupling effects. Additionally, to reduce chip area and assembly, the sensing oscillator is implemented with inverter-based active resonators instead of using either on- or off-chip inductors. The prototyped 3-D touch sensor is fabricated using 65-nm CMOS process technology and consumes an area of 2 mm2, with a 2.3-mW power consumption from a 1-V power supply. Measured together with a 3.4′′ HTC standard mobile screen, the sensor achieves an 11-cm Z-direction sensing range with a 1-cm resolution, demonstrating the potential implementation of 3-D finger position sensing in a mobile device.

A 10-bit 2-GS/s mixed-signal baseband (BB) circuit, which enables a self-healing 60-GHz 4-Gb/s radio-on-chip implemented in a 65-nm complementary metal-oxide semiconductor, is described. The BB circuit autonomously senses and optimizes transmitter (TX) P1dB, OIM3, and image suppression, reducing the yield loss because of process variations. On-chip test tones are generated using a 10-bit 2-GS/s current-steering digital-to-analog converter (DAC) and direct digital frequency synthesizer (DDFS). Using the generated test tones, the aforementioned impairments are measured by an envelope detector at the power amplifier output. Based on this information, the programmable digital IQ phase amplitude and offset controller (IQ_CTRL) in the BB circuit improves the TX image suppression from -32.4 to -42.6 dBc, and digital control signals generated by the on-chip self-healing controller heal the TX P1dB and OIM3 from 9.5 to 13.2 dBm and from -32.5 to - 40 dBc, respectively. In terms of achieving the target specifications, namely, TX image suppression , , and , healing increases yield on ten dies from 0% to 100%. The BB circuit consumes only 49 mW, of which 37 mW comes from the DACs and 12 mW from the DDFS and the IQ_CTRL.