Analysis of a microwave patch antenna array for reflection measurements

Microstrip antennas and arrays are widely used antenna technology in the frequency range of 1 GHz to 100 GHz. Microstrip antennas are simple and compact, and with current printed circuit technologies they are easy to manufacture. They are used in various applications such as; satellite communications, biomedical, mobile phone technology, radar, wireless local area networks and many other applications. This research focuses on developing a microstrip antenna to be used in an array that operates in a dual-band frequency range. The long term aim of this research is to develop an antenna array which can be used for the application of breast cancer detection. Two dual-band antenna elements are developed for this research and the antenna elements are arranged in a 2×2 array. Each antenna array has been designed and manufactured on a Rogers 4003 substrate. The design of the antenna elements were such that it operated in the frequency range of 5 GHz to 7 GHz creating an effect of wideband frequency operation. Four resonant frequencies were used in the range 5-7 GHz. The antenna elements were designed and simulated using the ANSYS HFSS software platform. Five antenna arrays were tested experimentally. The initial work is to study the reflections from an object and the phase information of the reflection is analysed. A simulation model of the reflection analysis is conducted and a metal object is used for this purpose to get better understanding of the behaviour of antenna elements in an array and how effectively the phase information can be extracted to find the reflecting body’s nature. The antenna elements built and tested match the simulation results well. The phase of transmitted signals has been measured experimentally and the results obtained were similar to the simulations and theory. The electric field information from the simulation has also been studied. This analysis provides a better understanding of how the reflected signals are received at the receiver antenna and it is expected that in future this method of analysis can be implemented for complex object identification