Design of millimeter-wave low-power OOK de-modulator for wireless chip-to-chip communication

Abstract

Data throughput between chips in a module, or modules, has significantly increased. Electrical inter-connect is usually used to transmit data between chips or modules by using cables or PCB board. However, it may cause many problems such as dielectric loss and cross talk as a required data rate increases. To solve this problem, many researchers conduct studies on the electrical interconnect such as SERDES to cover high data rate, but there is a limit by a material characteristic. Optical interconnect is most popular alternative for the electrical interconnect because it has a wide bandwidth, and an optic fiber has a low signal loss character-istic. However, it is too expensive to be used in many chips. Inductive and capacitive coupling is the other alternative that operates at low power consumption and high data rate. However, it can only be applied to the vertical structure such as 3-D devices, a fine alignment mismatch of each coupler significantly degrades the overall performance. The wireless interconnect by using millimeter wave is on the rise for the alternative because it satisfies both a high speed operation and a low power operation that is an important characteristic required for chip-to-chip communication. In this thesis, the millimeter wave low power OOK demodulator is designed. The target performance for chip-to-chip application is 16 Gbps over 5 cm. OOK modulation scheme is chosen because its system architecture is simple, so a low power con-sumption and a small chip size is possible. Proposed OOK demodulator operates at 77 GHz frequency and consists of a square-law detector and a baseband amplifier. The proposed detector is a gain-boosting detector with an active load. PMOS transistor is used for a load and increases both a voltage responsivity of the detec-tor and a gain of the baseband amplifier. The baseband amplifier has a wide bandwidth characteristic but is configured by multi stages of the differential amplifier. The wideband characteris...