IOTCo, a sister company of SmartBin Ltd, provide sensors for remote monitoring applications. The sensors are used to track the position of containers and the condition of the contents within the containers, communicating over cellular networks, as well as the latest IoT networks directly to the SmartBin Live platform. On SmartBin Live, data from SmartBin sensors are presented; giving a war room view of operations and generating optimized routes for the drivers.
Problem to Be Solved
The main task was to investigate the most suitable 868 MHz antenna for a Sigfox/LoRA transceiver module. This was followed by design work to match the impedance on the RF section of an Uplink Sigfox module to a 50 Ohm antenna and the final phase of the project was to investigate the best location for an antenna on a GSM/3G module where the antenna’s free space radiation characteristics is preserved without affecting the radiation characteristics of the antenna.
A broad range of 868 MHz antennas were investigated and a report was presented to the company that outlined the properties and limitations of various types of antenna. In this report the most suitable antenna for the preferred transceiver module and space constraints was recommended. This was followed by experimental work in which a solution for mitigating antenna detuning was proposed and a matching circuit recommended. In the second phase of the project, a GSM/3G antenna was tested in free space using a network analyser. These tests confirmed operation at GSM (900MHz), DCS (1800MHz), PCS (1900MHz) and 3G (UMTS 2.1GHz) frequencies. The effect on the radiation characteristics of the antenna was then analysed by the placement of the antenna at different locations on the module as shown in the figure below. The best solution for minimum antenna tuning was recommended.
Impact & Benefits
The company received practical solutions to their antenna selection and performance challenges with an informed understanding of antenna fundamentals. Matching circuits were designed and the best location and orientation for antenna element placement recommended. The work contributed to the company’s target of using a common enclosure design housing for different communication protocols and corresponding antennae.