Available at: http://digitalcommons.calpoly.edu/theses/334
Date of Award
MS in Electrical Engineering
This thesis involves the development of a 2.4GHz phased array antenna for consumer wireless applications. 802.11g specifications include 11 channels from 2.412 GHz to 2.472 GHz. Each channel has a 22MHz minimum bandwidth with a 5 MHz center-to-center interchannel spacing. Design goals for the phased array include an operating frequency of 2.437GHz (channel 6 center frequency). The array antenna design procedure can be integrated into a future antenna laboratory experiment.
Design considerations for the antenna array include cost, producibility, compatibility with 802.11b/g devices, and performance. Dipole antenna elements are arranged in a linear array to simplify calculations and to provide an intuitive understanding of array fundamentals. A linear array can maximize signal to interference ratio (SIR) by placing pattern nulls in the directions of noise sources. The design includes eight radiating elements mounted at λ/2 intervals. Design specifications include a scanning range of 360 degrees in the H-plane. Each element’s phase and gain is controlled by a network capable of 180 degrees of phase delay and up to 15.5dB of attenuation to enable sidelobe cancellation.
This project includes array design, simulations and theoretical calculations, antenna array construction, and final design characterization. Measurements are compared to theoretical predictions yielding good results. The antenna array was connected to an access point and tested on a lab network. Successfully associating a laptop to the wireless router and browsing the router configuration pages confirm connectivity. Array functionality is evaluated at channel 6, the 802.11g center frequency. The array is also tested at the lower and upper frequencies of channel 6 to ensure less than 3dB SNR variation.
The thesis includes a sample lab, which includes: A prelab, a procedure, and sample questions.