A 5Gbps CMOS ASK modulator for 60GHz application

Abstract

This thesis proposes a simple ASK modulator for 60GHz application. Every independent chips and integrated modulator is fabricated with 0.13um 1P8M bulk CMOS technology. The proposed modulator integrates a VCO as a signal source, and a switch for ASK modulation. The fabricated chip has a dimension of 971um $\times$ 726um $\times$ 300um. It shows output power of -16.6dBm and tuning range of 4GHz, from 52GHz to 56GHz. The data rate of proposed ASK modulator is 5Gbps, which is the best among reported ASK modulator. It also consumes the least DC power, among the ASK Modulators with active component. The operation is simple, which makes less circuits and power consumption possible, in a view point of transmitter system. The VCO generates a CW signal of 60GHz with the DC power, and the switch receives the signal as an input. A base-band signal received as another input of switch induces the on/off operation of switch. Then, at an output of switch generates a ASK modulated signal, in 60GHz band. Each VCO and switch is optimized for Ask modulation. The VCO designed with cross-coupled topology, which is easily oscillated with low DC power. This topology has been widely used for VCOs in many applications, by reason of easily achievable symmetry of VCOs. A size of the fabricated VCO is 530um $\times$ 615.5um $\times$ 300um, with on-wafer test pads. An output power of the VCO is -6.35dB and tuning range is 4GHz. The VCO core consumes only 8.64mW, and shows the best power efficiency in comparison among previously reported VCOs, which is requirements for a signal source of ASK modulation. A phase noise is measured almost same with the simulated results, -86.5dBc/Hz at 1MHz offset. The proposed switch uses series-shunt topology with an impedance transformation concept, for optimizing the isolation. By using this concept, high isolation over wide frequency range is able without additional circuits or power consumption. The simulated and fabricated millimeter switch has a...