Filtering by
- All Subjects: Technology
- Creators: Electrical Engineering Program
This thesis details the design process of a variable gain amplifier (VGA) based circuit which maintains a consistent output power over a wide range of input power signals. This effect is achieved by using power detection circuitry to adjust the gain of the VGA based on the current input power so that it is amplifier to a set power level. The paper details the theory behind this solutions as well as the design process which includes both simulations and physical testing of the actual circuit. It also analyses results of these tests and gives suggestions as to what could be done to further improve the design. The VGA based constant output power solution was designed as a section of a larger circuit which was developed as part of a senior capstone project, which is also briefly described in the paper.
The honors thesis presented in this document describes an extension to an electrical engineering capstone project whose scope is to develop the receiver electronics for an RF interrogator. The RF interrogator functions by detecting the change in resonant frequency of (i.e, frequency of maximum backscatter from) a target resulting from an environmental input. The general idea of this honors project was to design three frequency selective surfaces that would act as surrogate backscattering or reflecting targets that each contains a distinct frequency response. Using 3-D electromagnetic simulation software, three surrogate targets exhibiting bandpass frequency responses at distinct frequencies were designed and presented in this thesis.
This honors thesis explores the potential use of LoRa technology for detecting moisture in a diaper. Tests of both onboard and external humidity sensors coupled with LoRa transmission are incredibly promising. The potential scale of the final device also shows much promise, measuring smaller than a U.S. dime. However, the estimated cost for producing these proof-of-concept units in bulk is $19.41 per unit. While this is believed to be a pessimistic estimate of the price, the cost of production remains too high regardless for large-scale implementation. The thesis concludes by emphasizing the need for further research and development to optimize the design and reduce the cost of production. Despite the limitations imposed by price, the idea of using LoRa in detecting moisture in a diaper remains intriguing and promising, however, RFID technology has many advantages, such as size, cost, and passive power features.
There are quite a few readily available products that one can buy if one looks past some of their flaws. A lot of these alarms either require a user to carry an extra communication device, or they are too big or expensive. The proposed solution merges all desirable features of a bike alarm into one module. In light of this, surveys were conducted to ascertain what these qualities would need to be. The top considerations for purchasing this alarm were how costly it would be, the false detection rate, and also the battery life. Additionally, the features that were most requested was the inclusion of a GPS and a camera. In order to incorporate these features, a three year plan was formulated which would culminate into a bike network in which each bike could communicate with other bikes. This would allow for an IOT network to be established, thus far exceeding expectations. The price point for this alarm is USD $10.00-15.00 and can come in a variety of colors. Additionally, this concept can be applied to many different scenarios, from protecting boats/jet skis and other aquatic vehicles, to houses as well. Furthermore, one could miniaturize this technology to be used in jewelry or accessories.