A device generates a model associated with a multi-rate system. The multi-rate system includes a system associated with a clock rate and a sample rate, and the clock rate is greater than the sample rate. The device identifies the clock rate of the multi-rate system based on the model, and identifies a portion, of the model, associated with the sample rate. The device applies clock rate pipelining to adjust the sample rate associated with the portion of the model so that the sample rate substantially equals the clock rate, and generates code associated with the model and the applied clock rate pipelining.
Various embodiments of a novel structure of a Ge/Si avalanche photodiode with an integrated heater, as well as a fabrication method thereof, are provided. In one aspect, a doped region is formed either on the top silicon layer or the silicon substrate layer to function as a resistor. When the environmental temperature decreases to a certain point, a temperature control loop will be automatically triggered and a proper bias is applied along the heater, thus the temperature of the junction region of a Ge/Si avalanche photodiode is kept within an optimized range to maintain high sensitivity of the avalanche photodiode and low bit-error rate level.
Systems and methods optimize hardware description generated from a graphical model automatically. The system may include an optimizer. The optimizer may add a serializer component and a deserializer component to the model. The serializer component may receive parallel data and may produce serial data. The serializer may introduce one or more idle cycles into the serial data being produced. The deserializer component may receive serial data and may produce parallel data. The serializer and deserializer components may receive and generate control signals. The control signals may include a valid signal for indicating valid data elements of the serial and parallel data, and a start the start signal for indicating the beginning of a new frame or cycle when constructing parallel data from serial data.
Avalanche photodiodes (APDs) having at least one top stressor layer disposed on a germanium (Ge) absorption layer are described herein. The top stressor layer can increase the tensile strain of the Ge absorption layer, thus extending the absorption of APDs to longer wavelengths beyond 1550 nm. In one embodiment, the top stressor layer has a four-layer structure, including an amorphous silicon (Si) layer disposed on the Ge absorption layer; a first silicon dioxide (SiO2) layer disposed on the amorphous Si layer, a silicon nitride (SiN) layer disposed on the first SiO2 layer, and a second SiO2 layer disposed on the SiN layer. The Ge absorption layer can be further doped by p-type dopants. The doping concentration of p-type dopants is controlled such that a graded doping profile is formed within the Ge absorption layer to decrease the dark currents in APDs.
Various embodiments of a novel structure of a Ge/Si avalanche photodiode with an integrated heater, as well as a fabrication method thereof, are provided. In one aspect, a doped region is formed either on the top silicon layer or the silicon substrate layer to function as a resistor. When the environmental temperature decreases to a certain point, a temperature control loop will be automatically triggered and a proper bias is applied along the heater, thus the temperature of the junction region of a Ge/Si avalanche photodiode is kept within an optimized range to maintain high sensitivity of the avalanche photodiode and low bit-error rate level.
A device is configured to receive optimization information associated with a model, determine an amount of delay to be inserted into the model, and determine a sampling factor by which a first data rate associated with a signal is to be modified into a second data rate. The device is configured to determine a region of interest, insert an upsampling block that upsamples the signal entering the region of interest based on the sampling factor, and insert a downsampling block, associated with a unit of delay, which downsamples the signal exiting the region of interest based on the sampling factor. The device is configured to convert the unit of delay into a fast delay block, corresponding to the amount of delay, and insert the fast delay block in the region of interest. The device is configured to generate code associated with the model, and provide the code.
Various embodiments of a germanium-on-silicon (Ge—Si) photodiode are provided along with the fabrication method thereof. In one aspect, a Ge—Si photodiode includes a doped bottom region at the bottom of a germanium layer, formed by thermal diffusion of donors implanted into a silicon layer. The Ge—Si photodiode further includes a doped sidewall region of Ge mesa formed by ion implantation. Thus, the electric field is distributed in the intrinsic region of the Ge—Si photodiode where there is low dislocation density. The doped bottom region and sidewall region of the Ge layer prevent electric field from penetrating into the Ge—Si interface and Ge mesa sidewall region, where a large amount of dislocations are distributed. This design significantly suppresses dark current.